Exploring non-cancer pain conditions in a community sample:
Transcription
Exploring non-cancer pain conditions in a community sample:
Exploring non-cancer pain conditions in a community sample: Critiquing a current conceptual model of the acute to chronic pain transition and examining predictors of chronicity by Cathryne Patrice Lang B.Psych(Hons) A thesis submitted in fulfilment of the requirements for the degree of Doctorate of Philosophy School of Psychology and Counselling Queensland University of Technology December 2008 ii iii KEYWORDS Chronic pain, acute to chronic transition, community sample, mixed-methods, longitudinal iv v ABSTRACT This program of research examines the experience of chronic pain in a community sample. While, it is clear that like patient samples, chronic pain in non-patient samples is also associated with psychological distress and physical disability, the experience of pain across the total spectrum of pain conditions (including acute and episodic pain conditions) and during the early course of chronic pain is less clear. Information about these aspects of the pain experience is important because effective early intervention for chronic pain relies on identification of people who are likely to progress to chronicity post-injury. A conceptual model of the transition from acute to chronic pain was proposed by Gatchel (1991a). In brief, Gatchel’s model describes three stages that individuals who have a serious pain experience move through, each with worsening psychological dysfunction and physical disability. The aims of this program of research were to describe the experience of pain in a community sample in order to obtain pain-specific data on the problem of pain in Queensland, and to explore the usefulness of Gatchel’s Model in a non-clinical sample. Additionally, five risk factors and six protective factors were proposed as possible extensions to Gatchel’s Model. To address these aims, a prospective longitudinal mixed-method research design was used. Quantitative data was collected in Phase 1 via a comprehensive postal questionnaire. Phase 2 consisted of a follow-up questionnaire 3 months post-baseline. Phase 3 consisted of semistructured interviews with a subset of the original sample 12 months post follow-up, which used qualitative data to provide a further in-depth examination of the experience and process of chronic pain from respondents’ point of view. The results indicate chronic pain is associated with high levels of anxiety and depressive symptoms. However, the levels of disability reported by this Queensland sample vi were generally lower than those reported by clinical samples and consistent with disability data reported in a New South Wales population-based study. With regard to the second aim of this program of research, while some elements of the pain experience of this sample were consistent with that described by Gatchel’s Model, overall the model was not a good fit with the experience of this non-clinical sample. The findings indicate that passive coping strategies (minimising activity), catastrophising, self efficacy, optimism, social support, active strategies (use of distraction) and the belief that emotions affect pain may be important to consider in understanding the processes that underlie the transition to and continuation of chronic pain. vii TABLE OF CONTENTS KEYWORDS ............................................................................................................... iii ABSTRACT................................................................................................................. V TABLE OF CONTENTS ........................................................................................... vii LIST OF TABLES ..................................................................................................... xiii LIST OF FIGURES ....................................................................................................xvi LIST OF ABBREVIATIONS................................................................................... xvii STATEMENT OF ORIGINAL AUTHORSHIP ........................................................xix ACKNOWLEDGEMENTS ........................................................................................xxi CHAPTER 1: INTRODUCTION ............................................................................. 1 Brief Overview of the Research .................................................................................... 1 The Experience of Chronic Pain in a Community Sample .......................................... 1 The Transition from Acute to Chronic Pain ................................................................ 2 Aims of the Research ................................................................................................... 3 Research Plan ............................................................................................................... 4 Significance of the Research ......................................................................................... 4 Prevalence of Chronic Pain.......................................................................................... 5 Low Recovery Associated with Chronic Pain ............................................................. 9 High Costs of Chronic Pain ....................................................................................... 10 Disability and Distress Associated with Chronic Pain .............................................. 12 Structure of the Thesis ................................................................................................. 13 Chapter Summary ........................................................................................................ 14 CHAPTER 2: LITERATURE REVIEW ............................................................... 15 Chapter Overview ........................................................................................................ 15 Definitions and Terms ................................................................................................. 15 Preventing Chronic Pain Development and Disability ................................................ 18 The Transition from Acute to Chronic Pain ................................................................ 22 Gatchel’s Conceptual Model of Transition from Acute to Chronic Pain .................. 23 Description of the Model .................................................................................................... 23 A Critique of the Model ..................................................................................................... 28 Predictors of the Development of Disability: Risk Factors ....................................... 32 Risk Factors: Variables from Prevalence Research ............................................................ 35 Risk Factors: Variables from Longitudinal Research......................................................... 36 Protective Factors ...................................................................................................... 41 Protective Factors: Emerging Variables ............................................................................. 44 Coping Strategies. ........................................................................................................... 45 Control Appraisal and Self Efficacy. .............................................................................. 47 Beliefs about Pain............................................................................................................ 49 Positive Affect. ................................................................................................................ 50 Optimism. ........................................................................................................................ 51 viii Social Support..................................................................................................................53 Examining the Limitations of Previous Research into Protective Factors ..........................54 Aims of the Research .................................................................................................. 56 Aim 1: The Nature of Pain in a Community Sample ................................................ 56 Aim 2: Exploring the Transition between Acute and Chronic Pain ......................... 58 Clinical Model of the Transition from Acute to Chronic Pain ...........................................58 Examine the Predictive Value of Risk Factors and Protective Factors...............................59 Chapter Summary ....................................................................................................... 60 CHAPTER 3: METHODOLOGY OF THE RESEARCH .................................. 63 Chapter Overview ....................................................................................................... 63 The Use of a Mixed-Methods Approach .................................................................... 63 Using a Mixed-Method Approach for the Research ................................................. 64 Choosing the Data Types ....................................................................................................65 Matching a Mixed-Methods Approach to Chronic Pain Research .....................................66 Optimising the Use a Mixed-Methods Approach ..................................................... 67 Description of the Study Methodology ....................................................................... 68 Design ....................................................................................................................... 68 Sample ....................................................................................................................... 69 Procedure .................................................................................................................. 71 Phase1: Baseline Study .......................................................................................................71 Phase 2: Follow-up Study ...................................................................................................71 Phase 3: Interview Study ....................................................................................................72 Ethical Clearance and Occupational Health and Safety Approval .....................................72 Measures ................................................................................................................... 73 Questionnaire: Phase 1 (baseline) .......................................................................................73 Experience of Pain and Disability ...................................................................................75 Graded Chronic Pain Scale ....................................................................................................75 Roland and Morris Disability Questionnaire .........................................................................76 Psychological Distress Variables .....................................................................................77 Center for Epidemiologic Studies Depression scale ..............................................................77 Pain Anxiety Symptoms Scale-20..........................................................................................78 Extensions to Gatchel’s Model: Risk Factor Variables ...................................................80 Fear-Avoidance Beliefs Questionnaire ..................................................................................80 Coping Strategies Questionnaire............................................................................................82 Extensions to Gatchel’s Model: Protective Factors .........................................................83 Chronic Pain Coping Inventory .............................................................................................83 Survey of Pain Attitudes ........................................................................................................84 Pain Self efficacy Questionnaire ............................................................................................85 Positive affect scale of the Affect-Balance Scale ..................................................................86 Life Orientation Test – Revised .............................................................................................87 Multidimensional Scale of Perceived Social Support ............................................................87 Questionnaire: Phase 2 (follow-up) ....................................................................................88 Semi-structured Interview: Phase 3 ....................................................................................88 Statistical Analysis .................................................................................................... 92 Questionnaire: Phase 1 (baseline) & Phase 2 (follow-up) ..................................................92 Semi-structured Interview: Phase 3 ....................................................................................93 Chapter Summary ....................................................................................................... 93 ix CHAPTER 4: PHASE 1 – BASELINE QUESTIONNAIRES (DESCRIBING THE COMMUNITY SAMPLE) .............................................................................. 95 Purpose of the Study .................................................................................................... 95 Brief Introduction ........................................................................................................ 95 Method ......................................................................................................................... 96 Sample ....................................................................................................................... 96 Measures .................................................................................................................... 98 Procedure ................................................................................................................... 98 Statistical Analysis ................................................................................................... 100 Internal Consistency ......................................................................................................... 100 Missing Data .................................................................................................................... 100 Results........................................................................................................................ 102 Comparisons across the Pain Samples: Demographic Data .................................... 103 Description of the Experience of Pain ..................................................................... 106 Pain Variables................................................................................................................... 106 Seeking Treatment ............................................................................................................ 110 Influence on Employment ................................................................................................ 111 Psychological Health and Disability ................................................................................ 113 Coping with and Attitudes towards Pain .......................................................................... 115 The Influence of Pain Site on Functioning .............................................................. 118 Discussion .................................................................................................................. 122 Nature of Pain in a Community Sample .................................................................. 122 Who Experiences Pain? ........................................................................................... 123 A Picture of the Pain Experience ............................................................................. 124 Strengths and Limitations of the Baseline Phase ..................................................... 127 Chapter Summary ...................................................................................................... 129 CHAPTER 5: PHASE 1 – BASELINE QUESTIONNAIRES (ASSESSING GATCHEL’S MODEL) .......................................................................................... 131 Purpose of the Study .................................................................................................. 131 Brief Introduction ...................................................................................................... 131 Method ....................................................................................................................... 132 Sample ..................................................................................................................... 132 Measures .................................................................................................................. 133 Statistical Analysis ................................................................................................... 136 Internal Consistency ......................................................................................................... 136 Missing Data .................................................................................................................... 136 Factor Analysis with the Coping and Attitude Subscales................................................. 137 Results........................................................................................................................ 138 Correlations between Gatchel’s Variables ............................................................... 142 Assessing Differences between the Acute and Chronic Pain subgroups ................. 143 Relationships between Gatchel’s Variables and the Proposed Extension Constructs ...... 143 Predicting De-conditioning: Regression Analyses .................................................. 144 Daily Interference: RMDQ scores .................................................................................... 147 x Global Disability: GCPS disability estimate.....................................................................149 Depression: CES-D scores ................................................................................................151 Anxiety: PASS scores .......................................................................................................152 Results of the Hierarchical Regressions combined ...........................................................156 Comparing the 3 Stages of Gatchel’s Model .......................................................... 157 Discussion ................................................................................................................. 161 Chapter Summary ..................................................................................................... 165 CHAPTER 6: PHASE 2 – FOLLOW-UP QUESTIONNAIRES ...................... 167 Purpose of the Study ................................................................................................. 167 Brief Introduction...................................................................................................... 167 Method ...................................................................................................................... 170 Sample ..................................................................................................................... 170 Measures ................................................................................................................. 172 Statistical Analysis .................................................................................................. 172 Results ....................................................................................................................... 173 Examining Gatchel’s Model ................................................................................... 173 Correlation Analyses for Gatchel’s Variables ..................................................................174 Correlations between Changes in Physical and Mental De-conditioning .........................176 Changes over Time: Repeated Measures t-Tests ..............................................................177 Predicting the Development of Chronic Pain ......................................................... 179 Predicting Chronic Pain Participants’ Pain Outcome at Follow-up ........................ 182 Resolved vs. Continued Chronic Pain ..............................................................................182 Discussion ................................................................................................................. 188 Examining Gatchel’s Model ................................................................................... 188 Pain Outcome at Follow-Up ................................................................................... 191 Predicting Chronic Pain Development..............................................................................191 Significant Predictors of Continuing Chronic Pain ..........................................................193 Chapter Summary ..................................................................................................... 194 CHAPTER 7: PHASE 3 – SEMI-STRUCTURED INTERVIEWS .................. 197 Purpose of the Study ................................................................................................. 197 Brief Introduction...................................................................................................... 197 Method ...................................................................................................................... 198 Sample ..................................................................................................................... 198 Procedure ................................................................................................................ 203 Data Coding and Analysis....................................................................................... 203 Results ....................................................................................................................... 205 The Experience of Pain ........................................................................................... 205 Descriptions of Pain ..........................................................................................................205 Doing battle. ..................................................................................................................205 New love. .......................................................................................................................206 Lighthouse. ....................................................................................................................206 Co-existence (with the gods). ........................................................................................207 Part of getting older. ......................................................................................................208 xi Influence of Pain on Self .................................................................................................. 208 Constant pain “Pain doesn’t rule my life” ..................................................................... 208 Episodic pain “You just do what you can handle” ........................................................ 210 Resolved pain “Move along and go onto something else” ............................................ 212 Suffering with the pain “It really drives me insane” ..................................................... 212 The Influence of Pain on Others “You snap at people when you shouldn’t” ................... 213 Coping with Pain .............................................................................................................. 214 Gatchel’s Model ....................................................................................................... 216 The Disability Sequence: Pain, Inactivity, Dysfunction................................................... 216 Mental De-conditioning: Struggling to Cope ................................................................... 218 Influence of Emotion: “Emotions do play a part for me” ............................................. 219 Influence of Personal Characteristics: ‘I’m a pretty resilient person”........................... 220 Attitude: “Woe is me” ................................................................................................... 221 Exhaustion: “It still wears you out a bit” ...................................................................... 222 Evidence of Mental De-conditioning: “Is everything going to be all right” ................. 222 Summary of the Disability Sequence. ........................................................................... 223 Crossover between Mental and Physical De-conditioning: “Exercise gives you a dose of euphoria as well” .............................................................................................................. 223 Protective Variables ................................................................................................. 223 Coping Strategies ............................................................................................................. 224 Self-talk and distraction: “Using our computer disk”. .................................................. 224 Rest and relaxation: “Pull back, relax, and just let it go for a minute”. ........................ 226 Getting help: “I try to get assistance more than anything” ............................................ 226 Exercising: “I just do my exercises and it goes away”. ................................................. 226 Optimism and Positive Affect: “Mind over matter”......................................................... 227 Self efficacy to Manage Pain: “Pain doesn’t stop me” ..................................................... 229 Beliefs about Pain and Pain Management ........................................................................ 230 “I don’t take pills or anything like that”. ....................................................................... 231 “If it gets bad, I’ll see a doctor”. ................................................................................... 232 Social Support and Solicitude Beliefs .............................................................................. 233 “Whinging and moaning”.............................................................................................. 233 “I have a fantastic partner”. ........................................................................................... 234 “Using a support group”. ............................................................................................... 234 Revisiting and Understanding the Questionnaire Data ............................................ 234 Categorising Respondents’ Pain Experience .................................................................... 234 Survey of Pain Attitude (SOPA) Items ............................................................................ 235 Discussion .................................................................................................................. 237 The Experience of Pain ............................................................................................ 237 Gatchel’s Model ....................................................................................................... 240 Interpretation of Quantitative Data Phases .............................................................. 242 Limitations of the Research ..................................................................................... 243 Chapter Summary ...................................................................................................... 244 CHAPTER 8: DISCUSSION & CONCLUSIONS .............................................. 245 Purpose and Overview of the Research ..................................................................... 245 The Experience of Pain in a Community Sample ...................................................... 246 Characteristics of the Different Pain Subgroups...................................................... 247 Influence on Healthcare Systems ............................................................................. 249 Comparison of Chronic Pain in this Community Sample with Clinical Samples ... 251 xii An Exploration of Gatchel’s Model.......................................................................... 254 Fit between Gatchel’s Model and the Pain Experience of this Community Sample254 Exploring the Extension Variables (Risk & Protective Factors) ............................ 256 Predicting the Development of Chronic Pain ...................................................................258 Predicting the Continuation of Pain ..................................................................................258 Transposing the Extension Variables onto Gatchel’s Model ............................................259 Contribution to Theory ............................................................................................. 259 Fear-Avoidance Model ........................................................................................... 260 Attachment-Diathesis Model of Chronic Pain ........................................................ 261 Practical Applications ............................................................................................... 262 Strengths and Limitations of this Research .............................................................. 264 Future Directions ...................................................................................................... 270 Conclusion ................................................................................................................ 271 REFERENCES ........................................................................................................ 273 APPENDICES ......................................................................................................... 303 Appendix A: Comparison between Brisbane and rural respondents available for the Phase 3 (interview) study .......................................................................................... 303 Appendix B: Baseline (Phase 1) Questionnaire ........................................................ 304 Appendix C: Comparison between pain respondents who provided pain duration and respondents who did not provide pain duration at baseline ............................... 315 Appendix D: Participant Information Sheet ............................................................ 316 Appendix E: Examining Gatchel’s Model with Low Back Pain Respondents ........ 319 xiii LIST OF TABLES Table 1 Selected Non-Australian Prevalence Studies of Chronic Pain Table 2 Examples of Average Pain Duration at Program Entry in Overseas 6 Patient Samples 21 Table 3 Probability of Postcode Selection 70 Table 4 Mapping the Risk and Protective Variables onto the Questionnaire Measures 74 Table 5 Semi-structured Interview Questions 91 Table 6 Description of the Measures used in Phase 1 to describe the Pain Experience of Respondents 99 Table 7 Internal Consistency for each of the Scales and Subscales 101 Table 8 Missing Data Imputed 102 Table 9 Demographic Information compared by Pain subgroups 105 Table 10 Comparison of Pain Variables between Acute, Intermittent and Chronic Pain subgroups 107 Table 11 Treatment-seeking Variables across the Pain subgroups 111 Table 12 Number of Respondents whose Employment was Affected by their Pain by Pain subgroup 112 Table 13 Frequency of Compensation Seeking for each Pain subgroup 112 Table 14 Average Scores for Psychological Well-being (depression; CES-D and anxiety; PASS) Measures by Pain subgroup 114 Table 15 Graded Chronic Pain Scale Classifications by Pain subgroup 114 Table 16 The Percentage of Respondent who reported that pain interfered with these Daily Activities (using the RMDQ) Table 17 115 Average Endorsement of the Coping Strategies and Attitudes contained in the CPCI, CSQ and SOPA by Pain subgroup compared with the Published Means of a Clinical Sample 117 Table 18 Psychological Distress and Disability Data by Primary Pain Site 120 Table 19 Description of the Measures used in Phase 1 (baseline study) 134 Table 20 Internal Consistency for each of the Scales 136 Table 21 Missing Data Imputed 137 Table 22 Varimax Rotation of the Six Factor Solution for the CSQ, CPCI and SOPA items 139 xiv Table 23 Correlations between Pain Duration and Measures of Gatchel’s key constructs Table 24 Comparison of Gatchel’s Variables between Acute and Chronic Pain subgroups Table 25 155 The Final Betas for the Predictors of the Physical and Mental Deconditioning Measures Table 31 154 Hierarchical Regression Analyses to Predict Anxiety Scores (PASS) Table 30 150 Hierarchical Regression Analyses to Predict Depression scores (CES-D) Table 29 148 Hierarchical Regression Analyses to Predict Disability using the GCPS disability estimate Table 28 145 Hierarchical Regression Analyses to Predict Disability using the RMDQ Table 27 143 Correlations between Measures of Gatchel’s key constructs and the Extension Variables Table 26 142 156 Analysis of Differences between the Stages identified in Gatchel’s Transitional Model of Pain 159 Table 32 Results of the Classification Scheme 161 Table 33 Demographic Characteristics of the Phase 2 Sample 170 Table 34 Internal Consistency for each of the Scales at Phase 2 171 Table 35 Missing Data Imputed 172 Table 36 Demographic Characteristics of the CHRONIC sample 173 Table 37 Correlations between Pain Duration and Measures of Gatchel’s Variables at Baseline and Follow-Up for Chronic Pain Respondents Table 38 Correlation Matrix for Changes Scores on Psychological and Disability Measures for Chronic Pain Respondents Table 39 177 Frequencies (%) of GCPS Classification Changes for Chronic Pain Respondents Table 41 176 Comparing Gatchel’s Variables between Baseline and Follow-up data collection for the CHRONIC sample Table 40 174 177 Details of the Participants who transitioned from Acute to Chronic Pain 180 xv Table 42 Comparison of Predictor Variables between the new Chronic Pain Participants and Resolved Acute Participants 182 Table 43 Univariate tests of Categorical Predictor Variables 184 Table 44 Univariate tests of Continuous Predictor Variables 185 Table 45 Results of the Binary Logistic Regression Predicting Resolved vs. Table 46 Continued Chronic Pain 186 Profile of Each of the Interviewees 199 xvi LIST OF FIGURES Figure 1 Gatchel’s Three-Stage Model: a conceptual model of the transition from acute to chronic pain 25 Figure 2 Flowchart of the study sample 69 Figure 3 Mapping the measures onto Gatchel’s Model 74 Figure 4 Defining the Phase 1 pain subgroups 98 Figure 5a Percentage of the acute pain subgroup with pain at each body site Figure 5b Percentage of the intermittent pain subgroup with pain at each body site Figure 5c 109 109 Percentage of the chronic pain subgroup with pain at each body site 110 Figure 6 Boxplot of depression scores by pain site 119 Figure 7 Boxplot of anxiety scores by pain site 121 Figure 8 Scatter plot of the discriminant function scores 160 Figure 9 Flowchart of questionnaires returned 170 Figure 10 Flowchart of the interview sample 197 xvii LIST OF ABBREVIATIONS ANOVA Analysis of Variance CES-D Center for Epidemiologic Studies Depression scale CI Confidence Interval CPCI Chronic Pain Coping Inventory CSQ Coping Strategies Questionnaire FABQ Fear-Avoidance Beliefs Questionnaire GCPS Graded Chronic Pain Scales IASP International Association for the Study of Pain LOT-R Life Orientation Test - Revised M Mean MSPSS Multidimensional Scale of Perceived Social Support NHMRC National Health and Medical Research Council NRS Numerical Rating Scale PASS Pain Anxiety Symptoms Scale PSEQ Pain Self Efficacy Questionnaire RMDQ Roland and Morris Disability Questionnaire SD Standard Deviation SR Self-reported SOPA Survey of Pain Attitudes xviii xix STATEMENT OF ORIGINAL AUTHORSHIP The work contained in this thesis has not been previously submitted to meet the requirements for an award at this or any other higher education institution. To the best of my knowledge and belief, the thesis contains no material previously published or written by another person except where due reference is made. Signature Date Sections of this research have been presented at the following conferences: Lang, C.P., Sullivan, K.A., Yates, P.M., & Hansen, J. (2008). Assessing Fear-Avoidance Beliefs in a community chronic pain sample. Paper presented at the Australian Pain Society annual conference; Perth, Australia. Lang, C.P., Sullivan, K.A., & Yates, P.M. (2007). 56% of respondents in a Queensland sample report significant pain: Examining the nature of significant pain in a community sample. Refereed Paper presented at the Australian Psychological Society annual conference; Brisbane, Australia. Lang, C.P., Sullivan, K.A., & Yates, P.M. (2007). Psychological symptoms do not worsen over time with chronic pain: An exploration of Gatchel’s (1991) model. Paper presented at the Australian Psychological Society annual conference; Brisbane, Australia. xx xxi ACKNOWLEDGEMENTS I would like to acknowledge and sincerely thank my supervisors, Dr Karen Sullivan (principal), Prof Patsy Yates and Dr Julie Hansen for the guidance and support that they provided me during my candidature. I would also like to thank Prof Jenny Strong and two anonymous examiners for their comments on this document. This project would not have been completed without the support and encouragement of my husband, Anthony, to whom I am eternally grateful. Thanks must also go to all of my colleagues and peers at the School of Psychology & Counselling who have paved the way for PhD research generally and acted as editors-in-chief for the various chapters; special thanks to Judy Fleiter, Shari Walsh, (Dr) Ioni Lewis and (Dr) Erin O’Connor. This research was supported by a grant from the Institute of Health & Biomedical Innovation, Queensland University of Technology. Chapter 1: Introduction 1 CHAPTER 1: INTRODUCTION Brief Overview of the Research This research has a dual focus; it describes the experience of pain in a community sample and it explores a conceptual model of the transition from acute to chronic pain (also known as persistent pain). The Experience of Chronic Pain in a Community Sample Over the last two decades much large-scale research has been conducted examining the prevalence of chronic pain using community samples. While the primary focus of this research has been on prevalence rates, some data on the nature of chronic pain in non-clinical samples has been gathered. From this research, it is clear that chronic pain in community samples is associated with psychological distress (Breivik, Collett, Ventafridda, Cohen, & Gallacher, 2006) and disability (Blyth et al., 2001), greater use of healthcare services (Blyth, March, Brnabic, & Cousins, 2004), and lower quality of life (Hoffman, Meier, & Council, 2002). However, the experience of pain across the total spectrum of pain conditions (including acute and episodic pain conditions) and during the early course of chronic pain is less clear. Such data may assist in healthcare planning to reduce associated psychological distress and physical disability and improve quality of life for those affected by long-term pain conditions. In addition, such data may increase our clinical knowledge about the mechanisms underlying the acute to chronic pain Chapter 1: Introduction 2 transition, which may then also inform the development of early intervention programs and other community-based healthcare programs. The Transition from Acute to Chronic Pain A conceptual model of the transition from acute to chronic pain was proposed by Gatchel (1991a). In brief, Gatchel’s model describes three stages that individuals who have a serious pain experience move through, each with worsening psychological dysfunction and physical disability. Disability status is consolidated as secondary reinforcers to remaining disabled develop, for example, solicitous responses from others or decreased domestic responsibilities. Two processes, mental and physical de-conditioning (described further in Chapter 2), act in tandem as an individual moves through these stages. Treatment which alleviates physical and/ or mental de-conditioning is advised to decrease chronic pain disability. While Gatchel’s Model is one of the few models which attempts to describe the acute to chronic pain transition, there is little direct empirical support for its concepts and the relationships it posits. The model was originally developed with low back pain clinical patients. It has since been extended to other pain conditions, although its focus on clinical patients remains. However, since chronic pain patients are a small subset of the total chronic pain population, assessing the value of this model in a non-clinical sample would seem worthwhile. In addition, Gatchel’s Model does not account for people who have a significant pain experience and develop chronic pain but report limited psychological or physical disability. Nor can this model be used to predict who is at risk of developing chronic pain disability. Further development of Gatchel’s model may be informed by other research, which has used large-scale community or Chapter 1: Introduction 3 primary care samples to identify a number of risk factors for the development of chronic pain (Gatchel, Polatin, & Mayer, 1995; Linton & Hallden, 1997; Picavet, Vlaeyen, & Schouten, 2002; Schultz et al., 2004; White, LeFort, Amsel, & Jeans, 1997). These include demographic variables (e.g., gender and age), pain variables (e.g., pain intensity) and psychosocial variables (e.g., catastrophising, fear-avoidance beliefs and a weak belief that pain will resolve). Examination of the literature also reveals that a number of protective factors, for decreased disability later in the chronic pain trajectory or decreased disability for other health problems, exist. Although few of these variables have been examined in relation to the acute to chronic pain transition, these variables may also be protective early in the pain trajectory (see Chapter 2). Specifically, active coping strategies, specific pain beliefs, self efficacy, positive affect, optimism and social support may be predictors of resilience against developing chronic pain disability. This research examines the value of these proposed risk and protective factors to predict the development of chronic pain and disability status, and also evaluates the usefulness of incorporating some or all of these variables into Gatchel’s Model. Aims of the Research This research aims to provide a comprehensive description of the nature and experience of pain (in particular, chronic pain) in a community sample. It will also examine how people with pain (who have not completed a clinical pain program) cope with their pain. This research also aims to assess the fit of Gatchel’s Model with the pain experience of a non-clinical sample by examining the main premises of the model, which are that mental and physical de-conditioning will increase over time and that Chapter 1: Introduction 4 physical and mental de-conditioning processes are linked. In addition, to improve the utility of Gatchel’s Model, possible risk and protective factors identified through the literature will be explored as possible extensions to this model. Research Plan This thesis presents the results of a large-scale prospective longitudinal project. Both quantitative and qualitative data collection methods and analysis were utilised, which allowed the study of multiple aspects of the experience of and transition to chronic pain (Onwuegbuzie & Johnson, 2006). The first two research phases used a postal questionnaire sent to randomly selected households across Queensland to collect baseline and follow-up quantitative data. The third research phase used semi-structured interviews to obtain an in-depth look at the experience of chronic pain and the processes that underlie its development with a smaller subset of the original sample. Before the methodology and results are presented, first, a closer and more detailed examination of the significance of research in this area is provided. The rationale for the project is then presented through a review of the previous literature about chronic pain and by a considered account of Gatchel’s Model and how this might be expanded (in Chapter 2). Significance of the Research Pain research generally has been identified as a priority funding area through the 2001-2011 Decade of Pain Control and Research announced by the American Congress (Turk & Okifuji, 2002). In Australia, pain research and treatment is also a national priority as was demonstrated at a recent world congress in pain (which was Chapter 1: Introduction 5 held in Sydney, Australia, by the International Association for the Study of Pain). Further, pain and pain management are a national health priority recognised for funding through the National Health and Medical Research Council’s Strategies Plan 2003-2006 (NHMRC, 2003). Some of the reasons that pain and pain management are a national health priority are clear when examining the prevalence, effects and long-term outcomes of chronic pain. Prevalence of Chronic Pain The prevalence of chronic pain in non-Australian and Australian samples is considerable. In a review of the prevalence literature published up until 1994, Verhaak, Kerssens, Dekker, Sorbi and Bensing (1998) report that these chronic pain prevalence estimates ranged from 2-40% with a median estimate of 15% across 15 non-Australian population and primary healthcare studies. Since this review, estimates of chronic pain prevalence in 23 samples are available for the United States of America and Canada, the United Kingdom, China and many countries in Europe. Most recently a community survey of chronic pain across 15 European countries and Israel was conducted (Breivik et al., 2006). The prevalence estimates for each of the countries ranged from 12% to 30% (weighted prevalence across countries = 19%). As can be seen in Table 1, prior to the Breivik et al. study, a number of independent prevalence studies had been conducted yielding considerable variation in their prevalence estimates. This is likely to be related to a number of factors, shown in Table 1, such as the type of chronic pain each study assessed (e.g., musculoskeletal, low back only, non-cancer), the definition of chronic pain used (e.g., length – 3 months vs. 6 months; frequency – every day, more days than not), Table 1 Selected Non-Australian Prevalence Studies of Chronic Pain Reference Tripp et al. (2006) Breivik et al. (2006) Rustøen et al. (2004) Eriksen et al. (2004) Ng et al. (2002) 1 2 Date data collected 2004 2003 2000 1994 2000 Country Research methods Ontario Canada Telephone-administered questionnaire; contacted 2167 households; non-random selection of person within household Computer-assisted telephone interview; conducted 46,394 surveys 15 European countries & Israel Norway Denmark Hong Kong China Mailed questionnaire to 4000 adults randomly selected from national register; sent a repeat questionnaire 6000 people (16+ yrs) randomly selected from national register; face-to-face interviews & SF36 questionnaire (written form) Interviewed 1051 adults randomly selected from the telephone directory; adult with DOB closest to interview date Response rate 49% 37% Characteristics associated with chronic pain Female; unmarried; lower income; poorer SR health; rural residence 1 19% 2 Varied per country N= 46,394 Pain > 6 months; pain in last month; pain ≥ 2/wk; pain ≥ 5 (110 NRS) for last episode 48.5% Pain > 3mths 24.4% Female; older individuals; divorced or separated; less education; receiving pension Pain > 6 months 13.5% Not reported Pain > 3 months 10.8% Female; older than 60 years N = 1067 54% Definition of chronic pain Pain persisting ≥ 90 days in past 6 months Prevalence N = 1912 73% N = 4083 47.7% N = 1051 After controlling for depression, rural residence was no longer associated with chronic pain (pain grade) Prevalence rate varied from country to country (range 12-30%) Reference Date data collected Country Research methods Hoffman et al. (2002) Not reported North Dakota USA 750 surveys sent randomly selected residents – urban and rural; sent 2 repeat questionnaires Sweden 3928 mail questionnaires Selected randomly from population register (20-74 years); sent 1 repeat questionnaires followed by a shorter questionnaire Bergman et al. (2001, 2002) 1995 Response rate 25% Definition of chronic pain Pain ≥ 6 months Overall 58% (rural = 66%; urban = 50%) Pain > 3mths persistent or occurs regularly during last 12mths 31.4% N = 188 70% N = 2755 Prevalence (widespread pain = left & right side of body and below & above the waist) Elliott et al. (1999) 1996 Grampian Scotland 5036 patients ≥ 25yrs randomly selected from patient lists of 29 general practices; postal questionnaire; 2 reminders sent Note. SR is self-reported. NRS is numerical rating scale. 78% N = 3928 Pain > 3 months Characteristics associated with chronic pain Not reported Older age, manual work, current/ former smoker, not having personal support, family history of chronic pain (regional pain) Female, older age, lower SES, being an immigrant, living in poor housing area, lower education, seldom drinking alcohol, not having personal support, family history of chronic pain (widespread pain) 46.5% Older age; female; council housing; retired or not working Chapter 1: Introduction 8 the population studied (e.g., adults, patients) and effort expended to recruit participants (e.g., the use of reminder letters). Regardless, these studies in combination demonstrate the size of the problem of chronic pain, which is sizeable and ranges from approximately 10% (Ng, Tsui, & Chan, 2002) to estimates as high as 50% or more in some areas (Hoffman et al., 2002). Australian studies of prevalence are impacted by similar inconsistencies in the figures reported, which may have resulted from targeting different pain types and the use of varying definitions of chronic pain. The only Australian population-based study of chronic pain was conducted in New South Wales, using a population health survey. Prevalence of chronic pain (daily pain > 3 months in the previous 6-month period) was 20% for females and 17.1% for males aged above 16 years (Blyth et al., 2001). There is an estimated 3.2 million people with chronic pain in Australia based on this New South Wales data (Access Economics, 2007). Blyth et al. (2001) conclude that chronic pain is a significant problem in both the Australian adult population and the working-aged population, and further, that chronic pain should be a research and intervention priority. Other research conducted in Australia has examined specific pain types or focused on specific populations. In terms of the most common chronic pain complaint (Dionne, 1999), low back pain, Walker, Muller and Grant (2004) reported a prevalence rate of 13.4% for chronic low back pain. Walker et al. used a population-based survey sent to a random sample of Australian adults selected from the electoral roll. They suggested that previous surveys designed as more general health or well-being surveys (not specific to pain) have underestimated the prevalence of chronic pain conditions through imprecise items and language (see also Blyth et al., 2001). Given the stricter definition used in this study and its focus Chapter 1: Introduction 9 on only one type (albeit the most common type) of pain, that is, low back pain, it is likely that the 20% estimate for all pain conditions provided by the Blyth et al. (2001) study may understate the problem of chronic pain in Australia. Two other Australian studies provide some data on pain. Chen, Devine, Dick, Dhaliwal and Prince (2003) showed that 26% of women aged over 70 years experience lower extremity pain (i.e., pain located in the lower leg, ankle and foot region). However, pain duration was not assessed. McClean and Higginbotham (2002) found that 27.8% of nursing home residents in rural New South Wales able to communicate (approx 60% of total sample) reported chronic pain. Forty-one percent of participants with chronic pain reported that the pain was severe. Due to the small number of Australian studies (n = 4) and frequent focus on a single pain type, these studies are only indicative of the problem of chronic pain in Australia. However, it is clear that, like the rest of the western world, chronic pain is a sizeable health problem in this country. Accordingly, further research examining the nature of significant pain in Australia is necessary. Low Recovery Associated with Chronic Pain While the problem of pain in terms of prevalence is substantial, the significance of chronic pain research goes beyond prevalence rates. There is evidence that the prognosis for people with chronic pain is poor. Annual recovery rate estimates range from 5.4% over a 4-year period (Elliott, Smith, Hannaford, Smith, & Chambers, 2002) through 8.7% using a 6-year follow-up period (Eriksen, Ekholm, Sjøgren, & Rasmussen, 2004) to 15% over the longest follow-up period – 12 years (H. I. Andersson, 2004). While it is difficult to discern why estimates of Chapter 1: Introduction 10 incidence and recovery rates for chronic pain vary from study to study3, it is clear that recovery from chronic pain conditions is relatively rare even over long time periods. Consequently, if chronic pain has a high incidence rate and (in comparison) a low recovery rate, an increase in prevalence rates can be expected. In combination with the aging population in many western countries (Elliott et al., 2002; Gatchel, 2004) and increasing prevalence rates with age (H. I. Andersson, Ejlertsson, Leden, & Rosenberg, 1993; Elliott et al., 2002; Elliott, Smith, Penny, Smith, & Chambers, 1999), the prevalence of chronic pain may rise dramatically. Increases in prevalence rates are projected to result in 5 million Australians with chronic pain by the year 2050 (Access Economics, 2007). High Costs of Chronic Pain In addition to increasing prevalence rates and low recovery rates, chronic pain is associated with significant costs to the community. Recently, the total annual cost of chronic pain in Australia was estimated to be over $34 billion (Access Economics, 2007). This equated to approximately $11,000 per Australian with chronic pain (Access Economics, 2007). Studies of chronic pain patients in the United States of America clearly demonstrate that the costs and level of medical intervention requested by, and provided to, patients with chronic pain is largely disproportionate to the ratio of patients with pain who progress to develop chronicity in benign pain conditions (see e.g. Gatchel, 1991b; Gatchel & Turk, 1996). Similar statistics are found in Europe and the United Kingdom (see Maetzel & Li, 2002 for a review). In a Chinese 3 Some possible reasons for the discrepancy in the estimates include: samples from diverse countries, differences in length of follow-up period, and differences in the manner in which the pain populations were identified (Eriksen et al., 2004). Chapter 1: Introduction 11 sample, three-quarters of the sample had sought medical attention for their pain, and one-third of those participants had sought intervention from more than one source (Ng et al., 2002) (see also Hart, Deyo, & Cherkin, 1995). Chronic pain is associated with unemployment and a reduction in efficiency at work (e.g., Ng et al., 2002). In terms of the costs to the Australian community, the primary costs identified have been to employers through lost productivity and workers’ compensation litigation. Many overseas studies have focused on absence from work as an estimate of the cost of chronic pain on employers and the workers compensation systems generally (e.g., Galizzi & Boden, 2003; Schultz et al., 2004). However, this type of measure may underestimate the cost of chronic pain to the work force. Blyth, March, Nicholas, and Cousins (2003) found that days absent from work only account for one third of the workplace loss, with participants reporting attending work but being less effective due to pain on three times the number of (equivalent whole) days they were actually absent from work. These figures are based on adults who were able to maintain employment – nearly 8% of the New South Wales sample was not working due to health or pain reasons (Blyth et al., 2001). Litigation figures in this New South Wales community sample were also significant. Nearly 9% of adults with chronic pain were involved with litigation, primarily through the workers’ compensation system (Blyth, March, Nicholas et al., 2003). In overseas patient samples, the figures are much higher. For example, 80% of an American patient sample were seeking or receiving compensation for their pain (Turk & Okifuji, 1996). Increases in chronic pain rates (due to low recovery rates and increases in the aging population of many western countries (Elliott et al., 2002; Gatchel, 2004) and Chapter 1: Introduction 12 some eastern populations (see Ng et al., 2002)) means that chronic pain is likely to become more of an economic burden. Postulating from the current cost of chronic pain (Access Economics, 2007) suggests the annual cost of chronic pain in 2050 will exceed 55 billion dollars. Disability and Distress Associated with Chronic Pain Not only are the community costs high, the experience of chronic pain is associated with significant disability and distress for the affected individual. The disabling effects of chronic pain reported vary across samples. Over 50% of a Chinese chronic pain sample reported some, and 33% reported moderate to severe interference with their daily life (Ng et al., 2002). In an Australian sample, disability caused by pain was reported by 13.5% of women and 11% of men (Blyth et al., 2001). Blyth et al. (2001) also noted the association of chronic pain with psychological problems. Chronic pain has been associated with depressive symptoms (Breivik et al., 2006) and lower quality of life (Hoffman et al., 2002). Finally, chronic pain, particularly widespread chronic pain, may be associated with increased mortality (H. I. Andersson, 2004). The reasons that pain research is a national priority in Australia and other countries are well documented. Of concern to public health professionals is the economic cost associated with chronic pain. Of concern to health professionals is the individual’s psychological distress and physical dysfunction. These concerns are compounded by predictions that chronic pain prevalence rates are rising. This thesis aims to provide information on the experience of those with chronic pain in the community and contribute to the theoretical knowledge base used to develop effective interventions to minimise the symptoms of chronic pain. Chapter 1: Introduction 13 Structure of the Thesis This thesis has eight chapters. Chapters 1-3 provide an examination of the aims of the research, and the factors and variables under consideration. Building on the thesis overview provided in this chapter, Chapter 2 provides some definitions to aid in understanding the chronic pain research and provides a detailed literature review, including what is known about how chronic pain develops and a framework for understanding the transition from acute to chronic pain. Chapter 3 details the methodology for the research and presents a rationale for its structure. Chapters 4-7 present each of the studies conducted as part of this research. In each of these chapters, the rationale, brief background and method of each study are detailed. The results and the significance of the findings are also briefly discussed for each of the studies. Because of the volume of results reported for the first research phase, Phase 1 is presented in two chapters. Chapter 4 describes the pain experience in this community sample and Chapter 5 presents an assessment of Gatchel’s Model. Chapter 6 depicts the second research phase; a quantitative follow-up of the Phase 1 (baseline) participants. Chapter 7 illustrates the final research phase of the thesis. This is a qualitative examination of the factors that people with pain believe are important during the transition to and for the management of chronic pain. Chapter 8 highlights the significance of this research and its overall findings; integrating the results across the studies. This chapter also details the strengths and limitations of this research, and offers some suggestions for future research. Chapter 1: Introduction 14 Chapter Summary In summary, this chapter introduced the topic of this thesis, pain in a community setting, a contemporary research concern during the Decade for Pain Control and Research, and highlighted the significance of this research. Prevalence rates for chronic pain are increasing and expected to further increase in countries with an aging population, like Australia. With these increases, the economic cost to healthcare systems and employers is also expected to rise. The impact on individuals is underscored by the potential for physical and psychological problems to be associated with chronic pain. Taken together, these studies indicate that chronic pain is a significant problem for Australian adults as well as for overseas populations. As can be seen in this brief overview, the nature of the problem of chronic pain is not well understood in Australia, and in Queensland, in particular. Population-specific data may assist in healthcare planning and service provision. In addition, although estimates of prevalence vary with the type of pain targeted and the definition of chronic pain used, further research into chronicity in pain conditions is clearly warranted on the basis of these preliminary prevalence estimates. The potential benefits gained from the prevention of chronic pain disability are clear in terms of financial, social and personal benefits. Chapter 2 begins with an overview of the common terms used in this research area before discussing the prevention of chronic pain development and associated disability. In order to prevent chronic pain, the transition from acute to chronic pain is examined and a framework for understanding this transition, and the possible risk and protective factors for the development of chronic pain are reviewed. Chapter 2: Literature Review 15 CHAPTER 2: LITERATURE REVIEW Chapter Overview This chapter presents a comprehensive literature review that provides the background for the research. Prior to presenting the literature review, some definitions are provided. The prevention of the development of chronic pain and associated disability is then detailed. This is followed by an examination of the acute pain to chronic pain transition and a model of this transition period, Gatchel’s Model of Transition from Acute to Chronic Pain. Additional factors – both risk factors and protective factors – that may extend this model are subsequently proposed. The research aims are presented at the conclusion of this chapter. Definitions and Terms The current definition of pain, provided by the International Association for the Study of Pain (IASP), is “An unpleasant sensory and emotional experience associated with actual or potential tissue damage , or described in terms of such damage” (IASP, 1986, p. s217; Loeser & Treede, 2008; Merskey & Bogduk, 1994). While the community’s perception is that pain correlates with tissue damage, the IASP definition clearly gives weight to the affective component of pain. This aspect is important in chronic pain because while tissue damage may or may not be evident, the affective experience of pain can be very debilitating and illustrates one difference between chronic and acute pain conditions. Many different terms are used with regard to pain types and chronic pain, in particular. Previously, the definition of chronic pain varied across clinical and Chapter 2: Literature Review 16 research literature, resulting in inconsistencies in literature in terms of the key features of chronic pain (e.g., prevalence rates, predictors of disability; see Chapter 1). The chronic pain4 definition widely used in research in recent years is that recommended by the IASP (1986) as pain that persists past three months after onset. This timeframe is considered to encompass the expected healing times for most injuries and yet provide a clear research-appropriate definition. Evidently the first criterion for chronic pain concerns duration. A second criterion of chronic pain relates to the pervasiveness of pain. A chronic pain syndrome describes pain that is pervasive and constant in the individual’s life. Frequent reoccurring pain conditions (like migraine), therefore, do not meet the criterion of constant pain due to the intermittent nature of such pain; such conditions will not be considered as chronic in this research. Daily headache (persistent for greater than three months), however, would meet the criteria for chronic pain. Other terms include chronic benign pain, chronic regional pain, chronic widespread pain and chronic pain syndrome. The term, chronic benign pain, separates these pain conditions from those associated with malignant diagnoses such as cancer and acknowledges the link between tissue damage and pain is or has become, distant; pain cannot be accounted for by physiological injury (Verhaak et al., 1998). Some research further separates chronic regional pain from chronic widespread pain (e.g. Bergman, Herrstrom, Jacobsson, & Petersson, 2002). Chronic regional pain refers to pain that occurs in one or more area of the body. Widespread pain, on the other hand, refers to pain sites that exist in all four quadrants of the body, that is, on both sides of the body and both above and below the waistline. 4 More recently, the term persistent pain has been used. This term is believed to reflect that pain has persisted longer than anticipated but that it may not be a permanent condition. Chapter 2: Literature Review 17 Based on the broadness of these criteria, it can therefore be seen that the terms, chronic pain or chronic pain syndrome may incorporate “a heterogeneous group of different pain states with varying degrees of severity, distribution and functional impact” (H. I. Andersson, 2004, p. 47). Chronic pain has also been classified into subtypes based on type of injury or site of pain (IASP, 1986), such as low back pain or rheumatoid arthritis. Often research has focused upon one distinct pain type, possibly to reduce variability introduced due to pain type, given the range of pain states. Chronic pain differs from acute pain in more than these definitional components (that is, length and pervasiveness). This is more obvious when considering, as some authors have suggested, that there are three axes of chronic pain – time, severity and impact (disability) (e.g., Von Korff, Dworkin, & Le Resche, 1990). In terms of impact or disability, there are differences between acute and chronic pain on psychological and physical dimensions. First, disability is greater due to the longer length of pain. Second, chronic pain is associated with greater levels of psychological distress than acute pain (Gatchel & Oordt, 2003). Psychological distress is compounded with time. Third, while a comprehensive discussion of the physiology of pain is beyond the scope of this thesis, it should be noted that the underlying pathology associated with chronic pain can include changes to physiological systems including the nervous system (H. I. Andersson, 2004). Central nervous system sensitivity (that is, increased sensitivity to pain-like stimuli) is thought to develop and play a role in continued pain, after healing at the original injury site has taken place. Acute pain is pain that persists up until three months. Some authors refer to acute (0-4 weeks) and subacute pain (5-12 weeks) (Karjalainen et al., 2001b; Chapter 2: Literature Review 18 Poiraudeau et al., 2006). As acute pain is the first stage in the chronic pain trajectory, it is also examined in this thesis. It is estimated that 7-20% of acute low back pain becomes chronic (G. B. J. Andersson, 1999; Klenerman et al., 1995; Reid, Haugh, Hazard, & Tripathi, 1997). In some ways, acute pain is considered functional as it leads the individual to desist from harmful activities (e.g., touching a hot surface) or further damaging injured tissue (e.g., walking on a sprained ankle). As per chronic benign pain, once pain becomes chronic the link between pain and tissue damage is believed to become more remote. Given the variety of terms used in the pain literature, it is easy to see how different definitions may introduce variance into the results of research in this area. For the purposes of this study, the term chronic pain will be used generally to refer to pain lasting greater than 3 months, present on more days than not. Acute pain is defined as pain that persists up until three months. Preventing Chronic Pain Development and Disability As was discussed in Chapter 1, chronic pain is associated with significant financial and personal costs and has low recovery rates. Prevention of chronic disability is best achieved by early intervention. Because disability status begins to consolidate in the first 12 months post-injury and return to work is unlikely after this time, intervention is required as early as the first few months after an injury (Turner, Franklin, & Turk, 2000). Studies of early intervention programs in the acute or subacute phases of low back pain demonstrate that early intervention can increase the rate of return to work (Elders, van der Beek, & Burdorf, 2000; Hagen, Eriksen, & Ursin, 2000; Indahl, Haldorsen, Holm, Reikerås, & Ursin, 1998; Indahl, Velund, & Reikeras, 1995; Karjalainen et al., 2001b; Lindstrom et al., 1992; Patrick Loisel et Chapter 2: Literature Review 19 al., 1997; Schultz et al., 2008; Steenstra et al., 2006). The resultant reduction in number of sick days is often associated with a cost benefit to employers and workers’ compensations systems (Hagen, Grasdal, & Eriksen, 2003; Hlobil et al., 2007; P. Loisel et al., 2002) although this has not always been found to be the case (Steenstra et al., 2006) and more research is recommended (Tompa, de Oliveira, Dolinschi, & Irvin, 2008). Most of this research has been conducted with employee populations and samples accessed via workers’ compensation systems. Outside of a workers’ compensation scheme, one study has examined the cost effectiveness of early intervention for low back pain. Gatchel et al. (2003) also demonstrated early intervention (via a traditional chronic pain program) for people with acute low back pain who were at high risk of developing chronic pain (see Gatchel, Polatin, & Mayer, 1995) was effective in preventing the development of pain disability. While the results of the above studies demonstrate early intervention can be effective with low back pain, intensive early intervention for neck and shoulder pain was not better than usual care (Ekberg, Björkqvist, Malm, Bjerre-Kiely, & Axelson, 1994). Neck and shoulder pain have only been examined in one study; clearly more research into early intervention for pain at other sites is necessary. Samples that are more likely to contain patients with heterogeneous pain conditions are clinical samples. Unfortunately, patients at tertiary pain clinics often do not present until after they have experienced pain for many years; see Table 2 for some examples. The differences in average pain duration across samples and the large standard deviations within samples suggest there is much variability between these overseas patient samples. Regardless, it is clear that few people present to a pain clinic in the first 12 months of pain. Chapter 2: Literature Review 20 In Brisbane, Australia, the characteristics of several patient samples receiving treatment in a tertiary pain clinic have been reported. In two different samples from the same clinic, the mean pain duration ranged from 8.1 years (SD not reported; range 1-39 years) for 50 low back pain patients (Strong, Ashton, Cramond, & Chant, 1990) to 11.1 years (SD = 11.5; range 1-52 years) for 39 chronic pain patients (McCahon, Strong, Sharry, & Cramond, 2005). Such data suggests that patients in Brisbane also present to tertiary treatment programs after many years of suffering pain (although this is not always the case). The lag time between developing chronic pain and obtaining treatment at a pain clinic decreases the opportunity to effectively treat chronic pain. Because clinical patients typically have had chronic pain for many years prior to entry into the treatment program, they may be difficult to treat as their distress and associated disability is entrenched (Gatchel et al., 2003). Ultimately this also decreases treatment clinics’ capacity to decrease chronic pain disability. In addition, these studies of clinical samples have not shed light on the mechanisms of the development of chronic pain. Understanding the processes underlying the transition from acute to chronic may provide researchers and clinicians with knowledge that can be used to generate effective, early-intervention for a variety of pain conditions. Table 2 Examples of Average Pain Duration at Program Entry in Overseas Patient Samples Study Country/ region & population McCracken & Eccleston (2005) United Kingdom – chronic pain patients United States of America – chronic pain patients United States of America – chronic pain patients Cleveland – low back pain patients United States of America – chronic pain patients Netherlands – low back pain patients McCracken & Eccleston (2003) McCracken (1998) Heinberg et al. (2004) Turk et al. (1998) Vlaeyen et al. (1995) * median † mean ‡ range Ω standard deviation Average pain duration 87.5 months* Average pain duration (equivalent in Years) 7.3 Variance 12-528 months‡ 32.5 months* 2.7 3-372 months‡ 36 months* 3 3-372 months‡ 12 years† 12 13.01 yearsΩ 2285.65 days† 6.26 3151.69 daysΩ 9.75 years (men) 10.5 years (women)† 9.75 (men) 10.5 (women) 9.6 (men) 8.7 (women)Ω Chapter 2: Literature Review 22 The Transition from Acute to Chronic Pain To successfully treat chronic pain with early intervention, understanding the course and development of pain is vital (H. I. Andersson, 2004; Elliott et al., 2002). However, to date, the treatment or management of chronic pain once it is established has been a priority in the literature. As a result, most studies of chronic pain have focused almost exclusively on patient samples (that is, hospital or specialist pain clinic patients) who present to such services long after the onset of pain (e.g., Cannella, Lobel, Glass, Lokshina, & Graham, 2007; Heinberg et al., 2004; Keeley et al., 2008; McCracken & Eccleston, 2005, 2006). In addition, the section of the “course” of chronic pain that has yet to be extensively charted is that phase during the acute to chronic pain transition, that is, the first three months of pain. Exploration of the course of chronic pain with nonpatient groups generally occurs after chronic pain has been established – focussing primarily on changes within the chronic pain experience (e.g., changes in numbers of sites or location of pain) and spontaneous resolution of pain (e.g., H. I. Andersson, 2004; Bergman et al., 2002; Elliott et al., 2002). These studies show that the long term experience of chronic pain varies; the severity of pain can change in both directions – improvement and deterioration (see Bergman et al., 2002; Forseth, Førre, & Gran, 1999; Macfarlane et al., 1996). However, these studies lack the ability to map the week-to-week course of chronic pain, which may provide information about treatment options for pain patients. Moreover, clinical patient studies, the most common research type, do not report correlations between how long their participants have had chronic pain and other variables of interest that might assist health professionals to capture the typical course of the transition to chronic pain. While this is not unexpected if this was not Chapter 2: Literature Review 23 a primary aim of the research, it means that the picture of the chronic pain trajectory has yet to be charted. To summarise, chronic pain disability may be prevented through early intervention, although successful treatment has been primarily for low back pain. Yet, the factors leading to chronic pain are not well understood. Greater understanding of the transitional aspects in the development of chronic pain may be able to assist in the development of more effective early intervention programs (particularly outside of workers’ compensation schemes) and for other pain sites. Better understanding of how people with pain cope with pain during the acute phase may inform prevention and treatment (Koleck, Mazaux, Rascle, & BruchonSchweitzer, 2006). Clearly, greater understanding about how people behave and cope during the acute phase is an important issue. Gatchel’s Conceptual Model of Transition from Acute to Chronic Pain Description of the Model A model that was presented at the World Congress for Pain in 2005 (in Sydney, Australia) and proposed by Gatchel (1991a; see also Gatchel, 2005) describes the stages that an individual moves through if they develop chronic pain disability. Gatchel (1991a, p. 281) originally offered this model as “a conceptual model … [which] present[s] a number of testable hypotheses and important treatment implications”. Later, Gatchel (1996) presented data to support the model, although this research base mostly relied on indirect empirical evidence. Whether the same mechanisms as proposed by Gatchel occur in the transition from acute to chronic pain in non-clinical samples is unknown. Regardless, this model provides a useful framework to examine the psychosocial mechanisms of the transition into Chapter 2: Literature Review 24 chronic pain and related disability. It may be possible to extend this model to be more useful clinically and to guide theoretical understanding of the development of chronic pain. Gatchel’s (1991, see also Block, Gatchel, Deardorff, & Guyer, 2003; Gatchel, 1996; Gatchel & Dersh, 2002) conceptual model arose from sports medicine principles, which guide the rehabilitation of athletes (Mayer & Gatchel, 1988). Gatchel proposed that lengthy periods of inactivity increase the likelihood of developing dysfunctional behaviour patterns, both physical and psychological. Gatchel’s Conceptual Model of Transition from Acute to Chronic Pain (hence referred to as Gatchel’s Model) identifies three stages that follow the onset of pain or injury (see Figure 1 for a diagram). Patients move sequentially through these stages. Stage 1 describes the initial acute pain stage and the emotional response to the injury or pain onset (Gatchel, 1991a, 1996; Gatchel & Dersh, 2002; Gatchel & Kishino, 2006). During this stage, individuals may experience anxiety and fear of causing re-injury or increased pain, as well as the associated consequences of the injury or pain itself on their daily lives. This stage is portrayed as an adaptive response to minimise further harm (Gatchel, 1996). Stage 2 occurs when pain does not resolve. This stage usually emerges after 2-4 months, the reasonable rehabilitation time for an acute injury (Gatchel, 1996; Gatchel & Dersh, 2002; Gatchel & Kishino, 2006). Further psychological distress develops as a result of the continued pain (Gatchel, 1991a, 1996; Gatchel & Dersh, 2002). According to Gatchel’s Model, psychological distress at this stage is sufficient to interfere with recovery and impede intervention outcomes. Some of the behavioural and psychological reactions that may be seen at this stage are depression and learned helplessness, and anxiety disorders, amongst others. Gatchel (1991a) Chapter 2: Literature Review 25 This figure is not available online. Please consult the hardcopy thesis available from the QUT Library Figure 1. Gatchel’s Three-Stage Model: a conceptual model of the transition from acute to chronic pain. From Gatchel (1991a). notes that the type of psychopathology will be influenced by current environmental and socioeconomic factors in addition to individual premorbid psychological characteristics. For example, for an individual with a premorbid depressive personality who is seriously affected economically by loss of a job due to the pain and disability, depressive symptoms are greatly exacerbated during this stage. Similarly, an individual who had premorbid hypochrondriacal characteristics and who receives a great deal of secondary gain remaining disabled, will most likely display a great deal of somatization and symptom magnification (Gatchel, 1991a, p. 283). Stage 3 is the final stage in the progression of chronic pain (Gatchel, 1991a; Gatchel & Dersh, 2002) produced by unresolved or increasing psychosocial dysfunction (Gatchel, 1996). This stage is characterised by adoption of a “sick role” (i.e., acceptance of a life of diminished activity and social responsibilities). Often there is reduced interest in all activities outside of those necessitated by the pain Chapter 2: Literature Review 26 condition, such as doctor’s appointments (Gatchel, 1996). Disability status is consolidated during this stage as other reinforcers to remaining “disabled” develop, for example, increased interaction with family members or decreased caretaker responsibilities. While Gatchel and colleagues do not place a time period on the development of this stage, signs of chronic disability begin to become evident between 6-18 months after pain onset (Krause & Ragland, 1994) and, as mentioned previously, return-to-work is unlikely after 12 months post-injury (Turner et al., 2000). Other authors have also described clusters of pain patients that resemble Stage 3 patients of Gatchel’s Model. For example, Stage 3 may be likened to the dysfunctional classification described by Turk and Rudy (1988), which was characterised by a profile of more severe pain, greater interference in daily life, reduced activities, greater affective distress and lower perceived ability to control one’s life. This profile accounted for approximately 43% of their sample of 122 adults attending an outpatient pain clinic. The characteristics of Stage 3 patients are also similar to people described as having a chronic pain syndrome (Grabois, 2002; Von Korff et al., 1990). Symptoms associated with this syndrome include: vegetative signs of depression; psychological distress and demoralization; preoccupation with the pain experience; impairment of interpersonal relationships; excessive use of healthcare and pain medications; significant activity limitations in work, family and social life; and adoption of a chronic sick role (Von Korff et al., 1990, p. 280). According to Gatchel’s Model, in addition to these three stages, a cycle of mental de-conditioning and physical de-conditioning exists. These two deconditioning syndromes are overlaid on the model’s stages. Gatchel (1991a) Chapter 2: Literature Review 27 describes mental de-conditioning as the development of a “layer” of behavioral and psychological problems that occur in response to the chronic pain and the patients’ attempts to cope with it. These problems prevent the individual from maintaining a productive lifestyle. They prompt cessation or disuse of normal functioning, with all psychological resources being expended in an attempt to deal with the prolonged pain and disability (Gatchel, 1991a, p. 280). A similar process has also been described by Price, Riley and Wade (2001). Mental de-conditioning may be considered any psychosocial barrier to returning to or maintaining a productive lifestyle, which occurs in response to pain. This is consistent with the biopsychosocial approach to pain, which identifies the increasing importance of psychosocial factors with the illness progression to remaining disabled (Gatchel, 1991a, 1996; Gatchel & Dersh, 2002; Guzman et al., 2002; Karjalainen et al., 2001a; Karjalainen et al., 2001b; Linton, 2000; Turk & Okifuji, 2002). According to Gatchel’s Model, people with chronic pain develop psychological distress as a result of exhausting their (mental) resources in failed attempts to alleviate their pain (Gatchel, 1991a, 1996). However, it is not clear if mental de-conditioning occurs as a result of or is the process that moves individuals through these stages. It seems that the persistence of de-conditioning symptoms does initiate the move from Stage 2 to Stage 3 (Gatchel, 1991a). The physical de-conditioning cycle is when the individual, in an attempt to prevent or alleviate pain, protects the painful area by minimising movement. This guarding results in decreases in muscle strength, endurance and flexibility, which in turn increase pain and effort required to complete physical tasks (Gatchel, 1996). As Chapter 2: Literature Review 28 pain increases, the individual further minimises movement and the spiral continues (Gatchel, 1991a). Mental and physical de-conditioning are separate processes. However, each of these de-conditioning processes influence and interact with the other. While physical de-conditioning is likely to occur initially, it may result in mental deconditioning (Block et al., 2003). For example, declines in mental health and self esteem occur as patients are less able to complete physical tasks (Gatchel, 1991a). Likewise, psychological distress may influence physical functioning (Gatchel, 1996). For example, motivation to get involved in work or recreational activities is likely to decrease with psychological distress, and reduce the physical involvement in these activities. Decreases in physical activities then further increases physical de-conditioning (Gatchel, 1996). Both these types of de-conditioning may feed back into the experience of pain intensity (Block et al., 2003; Gatchel, 1996). Much literature supports the link between psychological distress and greater pain severity (Crombez, Vlaeyen, Heuts, & Lysens, 1999; Turk & Okifuji, 2002). While both physical and mental de-conditioning may be important in the transition to chronic pain (Gatchel, 1996), the relative contribution of these factors to the development of chronic pain has not been established. A Critique of the Model Intuitively Gatchel’s Model provides a clear framework for how the components of chronic pain develop and influence each other, that is, physical and psychosocial components, which is consistent with the biopsychosocial model of pain. There is much support for the involvement of psychological variables in the transition between acute and chronic pain (see Linton, 2000 for a review). Chapter 2: Literature Review 29 Many chronic pain conditions are associated with higher rates of depression, anxiety, and substance use and personality disorders compared with both the general population and acute pain patient groups (see Gatchel & Dersh, 2002 for a review) (Benjamin, Morris, McBeth, Macfarlane, & Silman, 2000). There is evidence both that chronic pain precedes depressive symptoms for some individuals (Magni, Moreschi, Rigatti-Luchini, & Merskey, 1994) and that depressive symptoms precede chronic pain conditions for other individuals. Further, symptoms of psychopathology (that is, indicators of mental deconditioning) diminish with the successful treatment of chronic pain that results in a reduction in disability (Gatchel & Dersh, 2002). Gatchel (1996) described studies of low back patients that provide evidence for the development of psychological problems that parallel the development of chronicity of pain. However, to the author’s knowledge, the model itself has not been specifically evaluated with a pain population. Gatchel’s Model was originally developed to specifically illustrate the transition from acute to chronic back pain (Gatchel, 1991a). However, as other authors have commented on the similarity of concomitant psychological conditions found across pain conditions (e.g., Turk et al., 1998), this model may be able to describe the transition from an acute to chronic condition for a wide range of noncancer pain complaints. Further, Gatchel draws on research from other pain conditions (e.g., temporomandibular disorders, headache) to provide support for his model (Gatchel, 1996). Using research from other pain conditions implies that the model is generalisable beyond the pain condition it was initially developed to describe. Chapter 2: Literature Review 30 As the focus of Gatchel’s Model is those people who progress from acute to chronic pain, this model does not describe the patients who experience pain but do not progress to Stages 2 and 3. The importance of identifying the people who will progress through de-conditioning processes and why only some people progress through de-conditioning processes was highlighted by Gatchel himself (1991a). A number of studies have drawn attention to the presence of pain patients who continue to experience pain that they describe as severe, who do not have the accompanying disability indicators such as inability to return to work, reduced involvement in activities or significant psychological distress (Turk & Okifuji, 2002). Using Gatchel’s Model as a framework suggests that these patients (the ones who recover) do not decondition at the rate or to the level of their more disabled counterparts. Regardless, the model does not specify the process by which this happens nor the types of protective factors that may be important in minimising the risk of or level of mental de-conditioning that occurs. Nor does this model specify variables (other than the passage of time) that may be predictive of the transition from Stage 1 to the other stages. Conversely, the expectation, with this model, is that when (if) the pain resolves, so too should any comorbid psychological problems (Gatchel, 1996). In this sense, the model could be considered as describing a passive process. However, as chronicity develops active strategies are required to reduce pain and comorbid symptoms. While protective factors that prevent movement through the stages are not identified, some processes for reversing each of the de-conditioning syndromes are provided. Gatchel proposes that physical exercises are able to restore physical conditioning (see Block et al., 2003; Gatchel, 1991a for a fuller explanation of physical de-conditioning and pacing physical programs). Physical reconditioning is Chapter 2: Literature Review 31 also expected to ultimately decrease pain (Block et al., 2003). To counteract the effects of mental de-conditioning, Gatchel (1991a) suggests a return to productivity, for example, return to work or other daily activities. While this suggestion is not unreasonable conceptually, it has not been tested empirically nor have the mechanisms for how a return to productivity reduce mental de-conditioning been identified. As mentioned earlier, the process that moves individuals through the three stages is not clear. Gatchel (1991a, p. 283) states “if the pain persists past a reasonable acute period, this leads to the progression into Stage 2”. Persistence of de-conditioning leads to Stage 3. The model appears to have a reliance on time passing to move individuals through the stages. Further, it may be difficult to discriminate between the stages. While a time period (2-4 months) was suggested as a marker of the transition between Stages 1 and 2 (Gatchel, 1991a), no time marker was given for the transition between Stages 2 and 3. Although the descriptions of each stage provide a picture of an individual at each stage, these descriptions may not be as useful in assessing a specific pain patient to identify the stage in which they fall and to tailor treatment accordingly. For example, a patient in Stage 3 may require a more intensive program for them to return to meaningful activity compared to a patient in Stage 2 of the model. Notwithstanding these difficulties, being able to accurately identify patients in each stage may allow efficient and cost-effective allocation of resources to obtain the best outcome for each patient. In summary, the model proposed by Gatchel is a descriptive model of the transition from acute pain to a problematic chronic pain experience. It does not identify those pain patients who, despite the experience of chronic pain, do not develop severe disability. In its current conceptualisation, it does not identify factors Chapter 2: Literature Review 32 that facilitate the transition through the stages. To extend Gatchel’s Model for greater clinical utility, there is value in examining this model, with particular focus on the mechanisms that both predict and may prevent or reverse the transition from acute to chronic pain. Previous research has examined some predictors of the development of chronic pain, once an acute injury or pain episode has occurred. Inspection of this literature may provide insight into factors that could extend Gatchel’s Model. Predictors of the Development of Disability: Risk Factors Research examining the acute to chronic pain transition has focused on identifying predictors of the development of future disability; that is, predictors to discriminate between individuals who are likely to continue to experience pain (and disability) and individuals whose pain will resolve. Often the factors identified are known as risk factors, that is, factors that put the individual at increased risk of developing chronic pain. These types of predictors may complement Gatchel’s Model. Understanding these risk factors may be valuable in identifying those adults who will develop chronic pain. This is important because of the high economic cost of chronic pain disability as well as the burden it places on individuals (see Chapter 1). Interventions that reduce the number of people who develop chronic pain have the potential to be very cost effective. However, since large numbers of adults experience acute pain in a given year (Australian Bureau of Statistics, 2004) and most will have their pain resolve without, or regardless of, the intervention provided (Greene & Laskin, 1974), the expense of intervention for all pain cases nullifies the potential financial benefit of early treatment. Therefore identifying adults who are Chapter 2: Literature Review 33 likely to develop chronic pain prior to its development and intervening with this group only, would seem to be a cost-effective method of managing chronic pain. Selectively targeting pain interventions in this way also has the potential to reduce patient suffering and distress by preventing chronicity without burdening those patients at low risk of chronic pain with lengthy or involved treatment. Cost-effective intervention at the acute stage relies on identification of individuals who are likely to develop chronic pain (Gatchel, Polatin, & Mayer, 1995; Linton & Hallden, 1997; Turk & Okifuji, 2002; White et al., 1997). However, identifying useful predictors of the development of chronic pain has been difficult. Large prospective studies, either population-based or using acute pain patients, are required to make statements regarding causal factors (e.g., White et al., 1997)5 6. In addition, reliable data about the initial course of pain and individuals’ psychological status prior to the current pain experience is difficult for people with long term pain to provide (see Koleck et al., 2006). Considering the volume of literature that has examined predictors of chronicity, relatively few prospective longitudinal studies have been conducted (Turk & Okifuji, 2002), perhaps due the relative difficulty and expense of this type of research (Asghari & Nicholas, 2006). The results of the longitudinal research that has been conducted are inconsistent. Similar to pain prevalence studies, the evidence for most predictors varies with sample characteristics, e.g., type of pain diagnoses such as back pain or headache, and the variety of measures (often of the same construct) that have been used. Measures of depression are an often cited example, where researchers have used a single item, questionnaires (newly 5 A brief examination of the evidence for psychological factors involved in the acute to chronic pain transition provided by retrospective and/ or cross-sectional studies is provided by Koleck et al. (2006). 6 A review of the predictors of occupational disability was provided by Crook, Milner, Schultz, & Stringer (2002). Chapter 2: Literature Review 34 developed and standardised) or clinical interviews to measure a variety of constructs from depressed mood to a clinical mood disorder diagnosis (Banks & Kerns, 1996; Gatchel, 1996; Gatchel & Dersh, 2002; Sullivan, 2001). Rarely have the same predictors been re-evaluated in subsequent studies, which would allow for the replication of findings. As a consequence, while much research has been conducted, relatively little of it is longitudinal, and a reliable comprehensive set of risk factors has yet to be identified. In addition, the outcome measure used will influence the relationships reported. Initially, researchers used pain reduction as their outcome measure (e.g., Linton, Bradley, Jensen, Spangfort, & Sundell, 1989; Linton & Hallden, 1997; Richardson & Richardson, 1999; White et al., 1997). As pain is a subjective experience, influenced by culture, personality traits, and past experience (Osterweis, Kleinman, & Mechanic, 1987; Turk & Okifuji, 2002), pain report may not be an appropriately sensitive outcome measure. The second wave of research focused on function (e.g., Crombez et al., 1999; Schultz et al., 2004), which may be a better outcome measure as it is able to be objectively assessed and more closely reflects what interventions aim to achieve, decreased disability (traditionally via decreased pain). However, even function as an outcome criterion is affected by the chosen unit of measurement. For example, impairment in activities of daily living could be considered a gauge of more debilitating disability than non-return to work. The use of multiple measurements of an individual’s function, for example, both impairment in activities of daily living and impairment in social/ recreational activities provides a more robust measure of change and allows the significance of the impairment to be evaluated more fully than either measure alone; this is the measurement approach that was used in this research. Chapter 2: Literature Review 35 Risk factors have been examined in two types of studies. Prevalence studies have sometimes provided some information about the demographic factors that are associated with increased prevalence of pain. As described earlier, longitudinal studies of people with acute pain who develop chronic pain have been used specifically to assess a range of demographic, pain and psychological variables associated with the development of chronic pain. Risk Factors: Variables from Prevalence Research A number of demographic variables have been frequently associated with the prevalence of chronic pain in community samples (see Table 1 in Chapter 1, page 6). Primarily the demographic characteristics associated with greater prevalence of chronic pain are female gender (e.g., Elliott et al., 1999; Rustøen et al., 2004; Tripp, VanDenKerkhof, & McAlister, 2006) and older age (Elliott et al., 1999; Ng et al., 2002; Rustøen et al., 2004) although older age is not consistently reported (e.g., Tripp et al., 2006). In addition, chronic pain is sometimes associated with indicators of poverty such as living in council housing (Elliott et al., 1999) or a poor housing area (Bergman et al., 2001), low income (Tripp et al., 2006) or receiving a pension (Rustøen et al., 2004). Finally chronic pain prevalence has been linked to lower education (Bergman et al., 2001; Rustøen et al., 2004) and family history of chronic pain (Bergman et al., 2001). Similar results are reported in Australian samples; chronic pain in the community is associated with female gender (Blyth et al., 2001; McClean & Higginbotham, 2002; B. F. Walker et al., 2004), older age (Blyth et al., 2001), and lower education (Blyth et al., 2001). Chronic pain is also associated with indicators of poverty such as an absence of private health insurance and receipt of welfare Chapter 2: Literature Review 36 payments (Blyth et al., 2001). The data reported here has largely come from one New South Wales sample (Blyth et al., 2001). While this data are consistent with that from overseas samples, these results need to be replicated in another Australian sample. Risk Factors: Variables from Longitudinal Research While there is some clear evidence for demographic risk factors, psychological factors have generally been found to have greater impact on the transition from acute to chronic pain disability (Linton, 2000). This is reflected in the results of the studies described below, which highlight some of the risk factors that have emerged from the literature that has focused on the acute to chronic transition. More research has been conducted examining the transition to chronic low back pain than other pain aetiologies and a number of reviews of these longitudinal studies are available (Pincus, Burton, Vogel, & Field, 2002; Pincus, Vogel, Burton, Santos, & Field, 2006). Recently, a review of whiplash pain was undertaken (Kamper, Rebbeck, Maher, McAuley, & Sterling, 2008). These results of these reviews will be discussed here. In addition, because few longitudinal studies have been conducted examining other pain aetiologies and little replication has occurred, each of the studies using heterogeneous pain samples are described in detail. The first review of longitudinal studies examining the development of chronic low back pain included 18 cohorts recruited via primary care clinics, secondary care clinics (including hospital out-patients) and workplaces. Pincus et al. (2002) conclude that the evidence for depressive symptoms being related to worse outcome was the most consistently supported finding. This finding is consistent Chapter 2: Literature Review 37 with Gatchel’s Model, although this review does not provide support for additional complementary risk factors. The second review of longitudinal studies examining the development of chronic low back pain specifically examined fear-avoidance beliefs (Pincus et al., 2006). The authors concluded from their review of nine studies that there was little overall evidence for the link between fear-avoidance beliefs and pain outcome in the short or long-term, especially if considering studies that recruited participants within 3 weeks of their back pain episode. It may be that fear-avoidance beliefs have greater influence later in the pain trajectory (Pincus et al., 2006). One study that was not included in this review was conducted by Klenerman et al. (1995). They found that fear-avoidance beliefs were the best predictor of whether low back pain patients continued to have pain and disability (a combined measure) at 12 months, over and above demographic variables and history of low back pain. Other authors have also recognised the importance of fear-avoidance beliefs in the development of chronic pain (Crombez et al., 1999; Fritz, George, & Delitto, 2001). The conclusions that can be drawn about the value of fear-avoidance beliefs as a risk factor for chronic pain are not clear. A risk factor related to fear-avoidance beliefs is catastrophising. Catastrophising is a cognitive variable that has been examined extensively with pain patients with regard to treatment. It was recently identified as one of the most important factors associated with increased pain and poor adjustment to pain (Keefe, Rumble, Scipio, Giordano, & Perri, 2004). Catastrophising has also been examined in a longitudinal context in relation to the development of chronic pain in a Dutch community sample (Picavet et al., 2002). The authors of this study reported that pain catastrophising and also kinesophobia (fear of movement/ (re)injury), in Chapter 2: Literature Review 38 separate analyses, predicted low back pain at 6-month follow-up both for respondents with current low back pain and no back pain. In addition, in an examination of osteopath patients consulting for acute low back pain, catastrophising was the strongest predictor of self reported disability at 12 months, explaining 47% of the variance (Burton, Tillotson, Main, & Hollis, 1995). The third review of longitudinal studies focused on the development of whiplash (Kamper et al., 2008). Again, general psychological distress (mainly depressive symptoms) was consistently associated with poorer outcome. In addition, acute pain intensity was consistently associated with poorer recovery. Similar to the findings of the whiplash review, studies that have examined predictors of chronicity using other pain samples also have found that measures of pain intensity appear to be a consistently replicated psychosocial predictor (Sieben et al., 2005; White et al., 1997). The other replicated risk factor in heterogeneous pain samples is a weak belief that pain would resolve. For example, greater pain intensity, a weaker belief that the pain would resolve and constant temporal pattern of pain over the initial 3 weeks of pain were the significant psychosocial predictors of continued pain at 3 months, compared to those whose pain resolved, for 371 acute pain patients hospitalised for heterogeneous medical complaints (White et al., 1997). Older age, trauma diagnosis, longer periods of hospitalisation, and absence of surgery were the significant demographic and medical variables predictive of the continued pain at 3 months. These factors together accounted for 21% of the variance in predicting pain chronicity. However, gender was not a significant predictor in this sample. A study by Sieben et al. (2005), of general practice patients presenting with low back pain of less than 3 weeks duration, also found that older Chapter 2: Literature Review 39 age, greater baseline pain, greater number of previous episodes, and a lower level of education were significant predictors of chronicity. Linton and Halldén (1997), using less than 4 months absent from work in the previous year as the cut-off for an acute pain complaint, targeted 142 consecutive primary healthcare patients. For their sample, the significant psychosocial predictors of continued pain at 6 months included higher average pain in the past 3 months, more frequent pain episodes, greater number of pain sites, greater stress and depression experienced, greater belief that pain would become persistent, belief that they had a lower perceived chance of working in 6 months, and greater belief that pain increases with physical activity than those patients who did not have continued pain. Similarly, when examining self-reported function, all of the previous predictors for continued pain, plus longer duration of the pain problem and female gender were the significant predictors of impaired ability to complete activities of daily living. Schultz et al. (2004) examined 159 workers who had sustained a low back injury, recruited through a workers’ compensation board. They found that low expectations of recovery and low scores on the SF-36 Health Transition scale (perception of a change in health status) were the main predictors of non-return to work at 3 months post-initial examination. Low Skill Discretion scores (from The Job Content Questionnaire; Karasek et al., 1998) also predicted non-return to work, although this relationship was weaker than the psychosocial predictors. Demographic predictors were not reported. While this study is a more recent longitudinal study that has highlighted some possible risk factors, the representativeness of the sample is uncertain due to the low response rate (28% of those workers eligible for participation). Chapter 2: Literature Review 40 Outcomes measured at different time periods may also affect the usefulness of predictors. For example, Gatchel, Polatin and Kinney (1995) demonstrated that in a sample of acute lumbar pain patients (N = 324) presenting at a pain clinic, 11% were not working due to back injury at 6 months. Greater pain severity and higher scores on the Hysteria scale of the Minnesota Multiphasic Personality Inventory (MMPI) predicted disability. At 12-month follow-up, Gatchel, Polatin and Mayer (1995) reported that for the original sample plus additional participants (N = 421), pain severity, gender, presence of an insurance case (i.e., workers’ compensation, personal injury) and the Hysteria scale scores of the MMPI predicted non-return to work for the 7% of this sample who were not working. In summary, the published longitudinal research into the chronic pain transition indicates that there are inconsistencies in the variables studied (both predictor and outcome) and the way that these variables have been operationalised. Not surprisingly, there are inconsistencies in the results of the research, with little replicated support obtained for any particular variable, with the exception of depression/ psychological distress, acute pain intensity, beliefs about the likelihood of recovery from pain, and catastrophising. There is some evidence for fearavoidance beliefs. The evidence for gender is mixed; although there is more evidence for the predictive value of gender for function at longer term follow-up, with greater proportions of females developing disability (Gatchel, Polatin, & Mayer, 1995). Older age as a risk factor was supported in some of the studies (e.g., Sieben et al., 2005). Clearly further research is needed to clarify the role of acute pain severity, beliefs about the likelihood of recovery from pain, catastrophising, fear-avoidance beliefs, gender and age as predictors of chronic pain. Chapter 2: Literature Review 41 The results from the longitudinal studies described above have all come from overseas studies – from Canada, the USA and Sweden. Longitudinal research into risk factors for chronic pain in Australia has not been reported. In addition, while many of the studies detailed above utilised acceptable sample sizes, the nature of the recruitment of samples has resulted in studies with limited generalisability that are based on subgroups of pain sufferers; an approach that has potentially minimised important predictors. The use of a broader sample to improve the generalisability of research findings is required. A longitudinal population-based study will minimise the problem of subgroups and allow for the study of pain that is induced by a range of aetiologies. Finally, these studies have examined only risk factors. There has been inadequate attention devoted to the assessment of possible protective factors. Such factors might also contribute to an expansion or refinement of Gatchel’s Model by explaining why some people progress through the model as predicted and others do not. An examination of this literature, drawn predominantly from the broader context of health psychology, would seem important. Possible protective factors will be examined next. Protective Factors Consistent with the illness focus of early mainstream psychology and medicine, the traditional approach in chronic pain research has been to examine and explore risk factors (reviewed in the previous section). An alternative approach, more recently adopted in developmental and health psychology, is to examine protective factors (for e.g., see Bonanno, 2004). In the context of chronic pain development, protective factors are those factors that discriminate people with acute Chapter 2: Literature Review 42 pain whose pain is more likely to resolve or who have greater likelihood of not developing psychological distress symptoms. To think of it another way, what are the variables that predict psychological wellness despite pain? The examination of protective factors is an approach that is common in the areas of child trauma and bereavement (e.g., Bonanno, 2004; Bonanno, Papa, & O'Neill, 2001), sometimes referred to as resilience. Protective factors are more than simply inverted risk factors. The action of protective variables may vary and have effect in multiple and non-additive ways. For example, in the areas of bereavement and trauma exposure, positive emotion and laughter are associated with resilience via two means. The expression of positive emotion and laughter may both reduce the amount of expressed negative emotion as well as counteracting the effects of distress associated with negative emotion (Bonanno, 2004). When examining the development of chronic pain, there may be several advantages to concentrating on protective factors and resilience7. Most importantly, the study of protective factors may increase our understanding of the process by which people develop chronic pain and guide the refinement of Gatchel’s Model. As stated by Bonanno (2004), … dysfunction cannot be fully understood without a deeper understanding of health and resilience. By viewing resilient functioning through the same empirical lens as chronic forms of dysfunction and more time-limited recovery patterns, researchers will be able to examine and contrast each of these patterns (p. 26-27). Additionally, protective factors may provide a classification system with greater specificity than risk factors by identifying which people with pain are not at 7 The central components of resilience are displaying psychological wellness in the face of and after significant adversity (Cowan, Cowan, & Schultz, 1996; Rutter, 1999) and demonstrating flexibility to adapt to stressors (Lepore & Revenson, 2006), which may be applicable to chronic pain (see also Strand et al., 2006). Chapter 2: Literature Review 43 risk of chronic pain. Alternately, rather than replacing the role of risk factors in identification for early intervention, protective factors may complement identified risk factors to provide a more accurate combined method for classifying people at risk of chronic pain. Moreover, if key variables in preventing the development of chronic pain disability can be identified, these factors may also be important in treating disability or managing relapse for those already with chronic pain. Protective mechanisms are likely to provide an emphasis on personal resources that will fit with current treatment programs that encourage self-management. Consequently, protective variables may be able to be manipulated or targeted in such interventions. To more fully understand the protective factors involved with the recovery from pain is, therefore, one of the aims of the current study. Despite acknowledgement of the value of protective factors in other areas of psychology and the advantages of identifying and treating people with chronic pain, a resilience approach has not been trialled with adults who may develop chronic pain or as a method to further understand the process of the development of chronic pain. In contrast, what has been examined more fully by pain researchers is the prediction of adjustment to chronic pain after it is an established phenomenon. The term, adjustment, has generally been used to describe an individual who is coping with or managing the chronic pain experience better than their counterparts (Jensen, Turner, Romano, & Karoly, 1991; McCracken & Eccleston, 2003; Morley, Davies, & Barton, 2005). Two common outcomes through which an individual could demonstrate adjustment include psychological well-being (e.g., measures of depressive symptoms, anxiety or fear-avoidance beliefs) and physical functioning or disability (e.g., activity levels, objective measures of physical capacity such as lifting or grip strength) (Jensen & Karoly, 1991). Some authors (McCracken, 1998; Chapter 2: Literature Review 44 Turner, Jensen, Warms, & Cardenas, 2002) have used indices of pain (e.g., intensity, severity or duration) as another index of adjustment. Therefore the adjusted chronic pain patient is one that reports at least one of the following indices – less psychological distress, greater functioning despite pain, or less pain – than their counterparts. Adjustment may be the end result of resilience that is displayed by a person experiencing chronic pain. More recently, there has been a shift in the focus of pain research to investigate the concept of resilience with people with an established pain condition. To date, this focus shift has mainly been in the area of widespread pain conditions like rheumatoid arthritis (for example, see Strand et al., 2007; Strand et al., 2006) so the inclusion of protective variables in a study of musculoskeletal pain is likely to be an important advance. Protective Factors: Emerging Variables The variables selected for this research were chosen from the chronic pain adjustment or health psychology literature because they may also have a protective role during the development of chronic pain. The variables chosen for this study were also assessed as having the potential to prevent the development of physical and/or mental de-conditioning as described in Gatchel’s Model. Some variables are likely to act against both physical and mental de-conditioning, e.g., active coping strategies, self efficacy and social support. Others (e.g., positive affect and optimism) would be expected to influence mental de-conditioning to a greater degree. The protective factors selected for inclusion in this research were coping strategies, control appraisal and self efficacy, pain beliefs, positive affect, optimism, Chapter 2: Literature Review 45 and social support. The empirical evidence from which these variables were drawn is reviewed next. Coping Strategies. Recently, coping strategies have been used to predict disability and continued pain in acute patients (e.g., Koleck et al., 2006). However, the use of coping strategies has been more often examined in an attempt to predict adjustment to chronic pain (for a review, see Jensen et al., 1991). Generally findings support the use of active coping strategies (i.e., those that require the patient to be active in managing pain) as related to better adjustment. Conversely, passive strategies (e.g., hoping, praying, resting) are associated with worse adjustment. For example, lower depressive symptoms and greater life satisfaction is predicted by the use of coping strategies of ignoring pain, using coping self-talk, and increasing activities (Jensen & Karoly, 1991). In another sample, lower depression and lower anxiety were associated with lower avoidant coping (a similar construct to passive coping; e.g., resting) (McCracken, Eccleston, & Bell, 2005). In a Spanish sample of chronic pain patients, active coping strategies (but not passive strategies) influenced functional disability whereas passive coping strategies (but not active coping strategies) were related to pain intensity and depressed mood (Lopez-Martinez, Esteve-Zarazaga, & Ramirez-Maestre, 2008). Some research has found that pain severity may effect how coping strategies influence disability. For example, Jensen and Karoly (1991) found that higher physical functioning (measured as difficulty in completing activities of daily living and the frequency in which one engaged in activities within and outside the home) Chapter 2: Literature Review 46 was predicted by ignoring pain, diverting attention from pain and using coping selftalk for patients with low or medium pain severity only. In contrast, in a 6-month longitudinal study, Revenson and Felton (1989) found that coping efforts (including information seeking, considering the positive aspects of the illness experience, emotional expression, wish-fulfilling fantasy, threat minimization and self-blame) at baseline were unrelated to an increase, decrease or no change in physical limitations for 45 rheumatoid arthritis patients. The small number of participants and the short study period in addition to the heterogeneous nature of the sample (see below) may have resulted in a lack of power to be able to distinguish differences. An alternate explanation is that since the patients varied considerably on time since rheumatoid arthritis diagnosis (M = 6 years; SD = 8; almost one third had been diagnosed only in the previous 12 months), the differences within the sample’s placement on a disease time line may have masked differences in coping. This possibility highlights the need to examine these variables at a specified time period. Gatchel’s Model, which divides the continuum of pain into stages, will be a useful framework with which to examine the interaction of time with coping on chronic pain disability. A third possible explanation is that, while the use of coping strategies is related to current functioning, it is not predictive of future functioning. The present study will enable these explanations to be tested. The previous studies of pain coping and adjustment did not assess the factors that discriminate people who are protected from the development of chronic pain. One published study has examined coping ability in the transitional process from acute to chronic pain. Koleck et al. (2006) followed 90 general practice patients who presented with acute low back pain for 12 months. Using the Coping Strategies Questionnaire, the praying and distraction scales (in combination with an irrational Chapter 2: Literature Review 47 beliefs scale) were related to low function (a factor score based on measures of functional limitations and involvement with medical care). The other scales of the Coping Strategies Questionnaire – catastrophising, reinterpreting, and ignoring – when combined with other measures were not related to the development of functional or emotional non-coping. This study offers some support for praying and distraction subscales, in particular, although further exploration of the influence of specific coping strategies on clearly defined outcome measures during the development of chronic pain is necessary. The current research will provide this data. Control Appraisal and Self Efficacy. As has been alluded to, cognition (or cognitive strategies) is an important factor in adjustment to chronic pain. Self efficacy is an individual’s belief that they are able to act and their expectation of how easy or difficult action will be (Bandura, 1977). These expectations of success affect whether the person attempts continued activity (e.g., paid employment) or to actively manage pain (e.g., through relaxation techniques), as well as the level and duration of effort exerted towards achieving these goals (Ajzen, 1991; Bandura, 1977, 1982). Self efficacy has been likened to control appraisal, which are the “beliefs that one has the ability and resources to manage pain” (Jensen & Karoly, 1991, p. 431). Like coping strategies, a number of researchers have examined the commonly positive relationship between self efficacy and psychological functioning (Jensen & Karoly, 1991; see also Jensen et al., 1991). Self efficacy has been found to be predictive of depression, pain severity, daily interference and general activity in outpatients with chronic pain (Anderson, Dowds, Pelletz, Thomas, & Peeters-Asdourian, 1995). In a community sample of Chapter 2: Literature Review 48 adults with osteoarthritis, along with other factors, self efficacy was predictive of objective measures of physical functioning at 3 years (Sharma et al., 2003). In Jensen and Karoly’s (1991) study of multidisciplinary pain program inpatients, the relationship between the control appraisal and functioning was more complex. There was a significant interaction between control appraisal and pain severity, where those respondents who had high control appraisal and low or medium levels of pain had higher activity levels than the other groups (i.e., low control appraisals or high pain severity) (see also Jensen et al., 1991). Similarly, self efficacy was a significant partial mediator of the relationship between pain intensity and disability in a cross-sectional study of pain clinic patients (Arnstein, Caudill, Mandle, Norris, & Beasley, 1999). In Arnstein et al.’s study, self efficacy also partially mediated the relationship between pain intensity and depression. As can be seen, self efficacy and control appraisal beliefs have been examined previously in both longitudinal and cross-sectional research, and found to be significantly related with physical and psychological functioning. However, most cross-sectional research has relied on clinical pain samples (e.g., Arnstein et al., 1999), while the longitudinal research presented was specific to one type of pain (e.g., Sharma et al., 2003). The contribution of self efficacy across types of pain conditions and the influence of self efficacy during the acute to chronic transition have not been explored. Given the broad influence that self efficacy has demonstrated on both physical and psychological variables (e.g., Anderson et al., 1995), it may have a protective role in slowing or halting the progression to chronic pain as per Gatchel’s Model. Further, as Gatchel (1996) suggests, motivation (which may include an element of self efficacy) may mediate the relationship between mental and physical de-conditioning, this variable is important to examine. Chapter 2: Literature Review 49 Beliefs about Pain. Personal beliefs about health have been documented as having an important effect on an individual’s health behaviour and engagement with healthcare systems (Janz & Becker, 1984; Rosenstock, 1974). For chronic pain patients, some specific beliefs have been identified as risk factors (e.g., fear-avoidance beliefs). There is also some evidence that certain beliefs may be protective. Pain beliefs have been associated with psychological functioning, activity levels and use of medical resources (also described by Jensen & Karoly, 1991; Jensen & Karoly, 1992). In terms of psychological function, patients who endorsed that they did not believe themselves to be disabled had lower depressive symptoms and greater life satisfaction. For patients who reported low pain severity only, low solicitude beliefs8 were also related to better psychological functioning. Low disability beliefs9 were correlated with high activity levels, only for patients with low or medium pain severity. None of the other beliefs (appropriateness of medication, medical cure, solicitude, or links between emotion and discomfort) were significant predictors of activity levels (Jensen & Karoly, 1992). Jensen and Karoly’s study provides preliminary support for the positive contribution of the following beliefs: strong belief that one is not disabled, weak belief that significant others should provide care, and strong belief that there is a medical cure for one’s pain, in a sample of patients of a multidisciplinary pain program. The influence of these beliefs for non-clinical samples or during the development of chronic pain has not been explored. The proposed study will explore the above beliefs using the same measure as Jensen and Karoly (1992) in a community pain sample to assess their predictive value. 8 9 Belief that significant others should provide care and comfort Belief that one is disabled by pain Chapter 2: Literature Review 50 Positive Affect. Positive affect is another variable of recent interest in health psychology (see Pressman & Cohen, 2005 for a review). It is proposed to be related to coping generally and to the use of specific coping strategies. Positive affect is a positive emotion believed to promote an attitude of readiness or willingness to try new activities (see Strand et al., 2007) and is an important “factor in the process of resilience following adverse events” (Strand et al., 2006, p. 478). High positive affect in a person with significant pain may encourage them to try new coping strategies to manage their pain. There is some evidence that positive affect also increases physical health via an immune response (Pressman & Cohen, 2005; Salovey, Detweiler, Steward, & Rothman, 2000), lower levels of stress hormones (Pressman & Cohen, 2005) as well as decreased perception of pain through gateway type mechanisms (Strand et al., 2007). Positive affect has been investigated with several samples of people with widespread pain (Strand et al., 2007; Strand et al., 2006; Zautra, Johnson, & Davis, 2005). Zautra et al.’s (2005) study showed that for women with osteoarthritis or fibromyalgia syndrome, higher average positive affect (over 12 weeks) was related to less pain increases from week to week. Greater average positive affect was also associated with fewer increases in negative affect during weeks of more severe pain or greater stress. The results of Zautra et al.’s study suggested that it is presence of positive affect, rather than simply the absence of negative affect that promotes a less severe pain experience and combats the influence of negative affect. Similar results have also been reported with samples of rheumatoid arthritis patients (Strand et al., 2007; Strand et al., 2006). Positive affect reduced pain intensity over eight weeks Chapter 2: Literature Review 51 (Strand et al., 2006). In addition, high positive affect disrupted the relationship between pain and negative emotion. Further, while Revenson and Felton (1989), mentioned previously, reported positive affect was not directly related to disability, positive affect was related to pain coping efforts. This may provide another or an alternate method by which positive affect has a positive affect on managing pain. Positive affect appears to be related to pain severity and pain coping and may be valuable to explore as individuals move from acute to chronic pain, and in relation to Gatchel’s mental de-conditioning concept. Of particular interest is whether positive affect is predictive of functioning also, and remains predictive of pain severity over periods of greater than one week. Optimism. Optimism is another protective factor from the health psychology literature (Scheier & Carver, 1992). While there is some controversy about the nature of this concept and the factors that discriminate it from other psychological concepts, such as self efficacy, there is robust research that links optimism with physical health and psychological outcomes (Scheier & Carver, 1992). However, less research has been conducted with people with chronic pain specifically, including clinical groups. Optimism can be broadly defined as the emotional response that overlays the expectation of a socially desirable or advantageous future (Peterson, 2000; Peterson & Seligman, 2004). Optimism incorporates what is often referred to as hope (the belief that goals can be achieved and that pathways to achieve these goals exist or are viable), dispositional optimism (a general view that good things will happen) and optimism as an explanatory style (i.e., the attributions that individuals give to both Chapter 2: Literature Review 52 positive and negative events) (Peterson, 2000). Optimism has also been related to individuals’ ability to plan and focus on the future and active problem-solving skills (Peterson & Seligman, 2004). Optimism has been linked to greater engagement with preventative health behaviour (such as smoking cessation, seeking early intervention for medical conditions), less overt illness behaviour (e.g., days of bed rest), and fewer occurrences of acute and chronic illnesses (Seeman & Seeman, 1983). Optimism has also been related to better psychological outcomes (Scheier & Carver, 1992), for example, greater levels of optimism are negatively associated with postnatal depression, are positively associated with quality of life post heart surgery (Fitzgerald, Tennen, Affleck, & Pransky, 1993), and are negatively associated with distress among women with early stage breast cancer (Wimberly, Carver, & Antoni, 2008). Some authors have suggested that the strength of optimism has been underestimated through the practice of controlling for optimism with other demographic or contextual variables when examining coping (Novy, Nelson, Hetzel, Squitieri, & Kennington, 1998). Novy et al. (1998) found that optimism interacts with coping style or strategies to explain a greater proportion of the variance in individuals’ ability to manage pain. This suggests that optimism may have at least a partial mediating influence on the use of coping strategies in how well pain is managed. While the evidence for the influence of optimism on the development of chronic pain is not available, optimism has been related to the use of coping strategies in one clinical sample. Further, evidence for the influence of optimism in recovery from other health problems and for the prevention of acute and chronic Chapter 2: Literature Review 53 health problems exists. The method by which optimism has its effect, possibly through individuals’ ability to plan and focus on the future and use of active problem-solving skills, may prevent mental de-conditioning through a future focus and distraction from current challenges, and this possibility is explored in this research. Social Support. The availability of social support has been examined in relation to adjustment in people with pain – both in clinical and non-clinical samples. The perception of greater social support has been found to be protective against developing more severe pain (defined as a greater number of pain sites on the body) three years later (Bergman et al., 2002). In terms of adjustment to chronic pain, perceived social support makes an independent contribution to explaining the variance in depressed mood and pain intensity (Lopez-Martinez et al., 2008). In this study of chronic pain patients, higher social support was associated with lower pain intensity, which in turn was related to less disability. Although there was no direct relationship between perceived social support and functional disability, social support may indirectly decrease disability. Social support perceptions may also have a protective role during the development of chronic pain. For recently-diagnosed rheumatoid arthritis patients a larger social network was related to greater mobility one year later (Evers, Kraaimaat, Geenen, & Bijlsma, 1998). In the same sample, higher levels of perceived support at baseline predicted lower functional disability (two self-report measures and grip strength test) and lower pain severity at three- and five-year follow-up (Evers, Kraaimaat, Geenen, Jacobs, & Bijlsma, 2003). This study showed Chapter 2: Literature Review 54 that how well people manage their pain in the early stages of disease (participants were recruited within one year of diagnosis) is associated with their pain and functioning up to five years later. In another sample, higher levels of social support at baseline was an identified protective factor for self-reported physical functioning at three years for individuals diagnosed with osteoarthritis of the knee (Sharma et al., 2003). The evidence for perceived social support seems to be strongest and consistent across different pain groups (community pain sample, knee osteoarthritis and rheumatoid arthritis sufferers) compared to the other possible protective variables presented here, for which the evidence is mixed or limited. Further, in the ageing literature, social support is linked to increased activity levels also (Duke, Leventhal, Brownlee, & Leventhal, 2002), which prevent or slow physical dysfunction. This suggests that social support may be a valuable contribution to an extension of Gatchel’s Model and may act to mediate the speed of physical de-conditioning as described by his model. Examining the Limitations of Previous Research into Protective Factors The studies of protective variables that have been reviewed are limited by a number of aspects. Most use cross-sectional designs (e.g., Jensen & Karoly, 1991; McCracken et al., 2005; Strong et al., 1990). Conclusions about the relationships between predictors and adjustment are therefore difficult to make, because the direction of the relationship cannot be established and the influence of other factors (e.g., a third variable) cannot be ruled out. Separating out the relationship between pain, disability and psychological well-being has become a “chicken-and-egg” dilemma. These variables are described as influencing each other; however, the Chapter 2: Literature Review 55 logic of the direction of influence is circular, and changes with the focus of the research reported. Longitudinal rather than cross-sectional research designs are needed to explore directional and possible causal relations between protective factors and pain. Additionally, the use of clinical samples, who are presumably not coping with chronic pain adequately since they are seeking treatment, to examine relationships between coping-like variables and adjustment may limit generalisability. The narrow focus on clinical samples has resulted in overall little evidence that the results of treatment-seeking patient will generalize to untreated pain sufferers (Jensen & Karoly, 1992). This, coupled with the long average pain duration reported by such samples (e.g., 9.5 years in the Morley et al. (2005) study) makes it unlikely that clinical samples can inform knowledge and understanding of all people with pain, particularly those early in the course of chronic pain or those who have chronic pain but are not seeking treatment. The difficulty of discerning the results of the research reviewed into protective factors is further complicated by the diversity amongst pain patient samples. Many studies seem to have recruited heterogeneous samples in terms of their duration of pain (e.g., Revenson & Felton, 1989) or type of pain (e.g., Bergman et al., 2002). Such variability in samples may account for the difficulty in replicating the findings from one study to another. A larger study of significant pain in the community may address these issues of representativeness and restriction of range. Respondents may be able to be categorised according to variables such as pain duration or type of pain, and have the contribution of these factors explored. Nonetheless, given these preliminary findings, it would seem that variables such as Chapter 2: Literature Review 56 coping, pain beliefs and appraisal, positive affect, optimism and social support may be protective against developing chronic pain disability. Aims of the Research The research has two main aims. The first aim is to examine the nature of pain in a community sample. The second aim of this research is to explore the transition from acute to chronic pain with particular emphasis on Gatchel’s Model. This research will focus on non-cancer pain. Non-cancer pain was chosen to overcome some of the limitations of previous research that have been restricted to a site of pain as non-cancer pain is considered a broader category of pain than pain types differentiated by site (e.g., headache, low back pain). However, excluding cancer conditions will reduce variance introduced by clinical indicators (e.g., disease variables, malignancy) (Jay, Elliot, & Varni, 1986; cf Turk et al., 1998). As Gatchel’s Model was originally developed for low back pain and it has since been deemed appropriate for other musculoskeletal pain conditions (e.g., temporomandibular disorders), examining this model and the proposed extensions to it with a broader pain population may increase its usefulness. Aim 1: The Nature of Pain in a Community Sample In Chapter 1, the review of the literature showed that constant pain that persists after three months is associated with higher levels of psychological distress than acute pain conditions. The disability costs to society and the individual are equally bleak. Studies of overseas populations in addition to a general health survey conducted in New South Wales indicate that chronic pain is likely to be a significant problem for Australian adults. Although increases in prevalence rates (and Chapter 2: Literature Review 57 associated economic costs) are predicted, the nature of the problem of chronic pain is not well understood in Australia, nor in Queensland in particular. In addition, although estimates of prevalence vary with the type of pain targeted and the definition of chronic pain used, further research into chronicity in pain conditions is clearly warranted on the basis of these preliminary estimates. Data will be collected in one of Australia’s seven states and territories, Queensland. Queensland has the second fastest rate of population growth in Australia (Australian Bureau of Statistics, 2008); geographically, Queensland is the second largest state in Australia; and, by 2041 it is projected to be the second most populous Australian state (Australian Bureau of Statistics, 2005). Collecting data on the nature of pain in a community sample in Queensland serves two purposes. First, it provides Queensland population data, which has not been collected previously. While a full scale prevalence study was beyond the scope of this research, population data on chronic pain will be collected in order to comment generally on the healthcare planning and service provision requirements in rural and urban Queensland. Recently, community based treatment was identified as “appropriate for most people with chronic non-disabling pain” (Access Economics, 2007, p. vii). Second, this research will allow a more comprehensive description of chronic pain in a community sample than has been undertaken previously. Most of the knowledge about chronic pain including its presentation and associated disability are obtained from patient samples, who are long term sufferers and whom arguably represent the people with chronic pain who are not managing their pain experience. Many of the patients who present to tertiary pain services could be described as being at Stage 3 of Gatchel’s Model; also depicted by Turk and Rudy (1988) as dysfunctional. Yet, a community study conducted in New South Wales Chapter 2: Literature Review 58 demonstrated that over one third of adults with pain did not report that pain interfered with their daily life (Blyth et al., 2001). Clearly, this portion of the pain population may be missed by research using patient samples. Therefore, description of a community sample for comparative purposes for Australian patient studies will be valuable. In addition, exploring the nature of pain in a community sample allows for a broader spectrum of pain conditions to be assessed. Due to a focus on chronic pain, missing from the pain research is knowledge of the broader experience of pain, for example, people with longstanding intermittent pain. Specifically, data about the following areas will be sought: the type of acute and chronic pain, the sites of pain, perceived causes of pain, involvement with insurance systems, where people first seek treatment, and the amount of disability associated with these pain conditions. Aim 2: Exploring the Transition between Acute and Chronic Pain Recently, further research into the acute to chronic pain progression was identified as a priority research area in Australia (Access Economics, 2007). Currently, the pathways between acute and chronic pain are not well understood. Nor are the factors that predict continued disability or recovery from pain well delineated. These factors give rise to two research questions that fall under this broad aim. Clinical Model of the Transition from Acute to Chronic Pain The model proposed by Gatchel (1991a), which has indirect research evidence, may provide a framework for understanding individuals’ transition from Chapter 2: Literature Review 59 acute pain to chronic pain disability. Whilst this model was first proposed in 1991, it remains current in the literature (Gatchel, 2005). Therefore, a primary aim of this research is to explore Gatchel’s Model of the transition from acute to chronic pain disability. Specifically, this research will 1) explore the development of psychological distress as acute pain persists and meets the criteria for chronic pain, with particular focus on some of the psychological symptoms that have been associated with Gatchel’s concept of mental de-conditioning – depressed mood and pain-related anxiety – using a longitudinal study design, and 2) compare the development of physical de-conditioning in this sample with that which is predicted by Gatchel’s Model. Examine the Predictive Value of Risk Factors and Protective Factors Much of the literature presented earlier shows that there are inconsistencies in the results of research that examines risk factors for the development of chronic pain. One of the limitations of previous research is that subgroups of people with pain have been targeted which has resulted in studies with limited generalisability and may have minimised potentially important predictors. In addition, longitudinal research into risk factors of chronic pain in Australia has not been conducted. Similarly, many of the protective factors have not been examined in a community sample or with people early in the course of chronic pain. Therefore, this research will use a broader pain sample with the aim to improve the generalisability of the research findings, with the aim of replicating the results of previous overseas research regarding the predictive value of risk factors (acute pain severity, expectations of recovery, catastrophising, fear-avoidance beliefs, age and gender) in an Australian community sample. In addition, this Chapter 2: Literature Review 60 research will explore the predictive value of possible protective factors (i.e., coping, self efficacy, pain beliefs, positive affect, optimism and social support). Both risk and protective factors will be assessed with a view to incorporating these variables into an extension of Gatchel’s Model. The predictive value of protective factors will be compared with the predictive value of risk factors for chronic pain. Chapter Summary The chapter began with an overview of the common terms used in chronic pain research. The expression, chronic pain, includes a heterogeneous group of pain conditions that persist past 3 months and are often associated with affective distress and physical disability. It has been demonstrated that the prevention of chronic pain and its associated disability relies on clear understanding of the transition from acute to chronic pain. A model that provides a framework for understanding the transition process was proposed by Gatchel (1991a). One of the strengths of Gatchel’s model is that treatment recommendations are provided based on the proposed underlying de-conditioning processes that occur as chronic pain and disability develops. However, this model has focused solely on clinical samples, who are a small proportion of people with pain, and has little direct empirical support. In addition, the mechanisms behind some of the processes described are not clear. The description of Gatchel’s Model was followed by an examination of risk and protective factors that may provide a useful extension to this Model. Several possible risk factors were identified, although little research has examined these factors in Australian samples. Protective factors were examined also, although there is less evidence for their influence during the acute to chronic transition. Chapter 2: Literature Review 61 The chapter concluded with the two primary aims of this research. Chapter 3 presents the methodology used in the research to achieve these research aims. Chapter 3: Methodology of the Research 63 CHAPTER 3: METHODOLOGY OF THE RESEARCH Chapter Overview As was discussed in Chapter 2, the two primary aims of this research were to explore the experience of pain in a community sample and to examine the transition process from acute pain to chronic pain disability using Gatchel’s Model. To address these aims, a prospective longitudinal mixed-method design was utilised. This chapter describes the rationale for using a mixed-method approach, outlines the methodology for the research and provides a description of each of the study phases, the results of which are presented in subsequent chapters. The Use of a Mixed-Methods Approach Using a combination of quantitative and qualitative research methods is known as a mixed-method approach. Mixed-method approaches have been used for many years; however, these approaches have gained increasing attention as a specific methodology in the last 20 years (see also Axinn & Pearce, 2006; see Sandelowski, Voils, & Barroso, 2006). Particularly, mixed-method approaches have been used in health research in an effort to capture the complexity of the numerous factors that influence wellbeing (Morgan, 1998b). A mixed-method approach may offer a number of advantages over a single type of methodology. Axinn and Pearce (2006) state that “when a research problem calls for the combination of high levels of structure to test hypotheses and low levels of structure to discover new hypotheses, mixed-methods are particularly Chapter 3: Methodology of the Research 64 appropriate” (p.24). Mixed-method research is also believed to provide richer information about the concept under investigation (for a discussion see Onwuegbuzie & Johnson, 2006). Onwuegbuzie and Johnson (2006) suggests that an additional value of mixed-method research is that it enables the study of multiple aspects or multiple research questions in a single piece of research; while compensating for the weaknesses of each techniques (Axinn & Pearce, 2006). A mixed methodology was selected for this research for these reasons. Using a Mixed-Method Approach for the Research There are a number of ways that the various methods can be combined. In the most part, these methods are differentiated by the order in which data are collected and analysed. For example, classifications of these different approaches have been provided by Morgan (1998b) and Onwuegbuzie and Johnson (2006). The approach used in this research can be classified as a sequential mixed-method design (Axinn & Pearce, 2006). This means that the different types of data were collected one after another; data was collected through quantitative methods and then using qualitative methods. This particular approach is regarded as well suited to longitudinal research (Axinn & Pearce, 2006). Using this approach, the data from one phase are used to inform the following phases. This research used questionnaires (Phases 1 and 2; quantitative data) followed by semi-structured interviews (Phase 3; qualitative data). A qualitative approach was used in the later stages of the research to facilitate the interpretation of quantitative data, known as a contextual overlaying strategy (Onwuegbuzie & Johnson, 2006). Additionally, analysis of the large scale data set can guide the collection of the smaller less structured data set. For example, this information can guide the selection of Chapter 3: Methodology of the Research 65 participants (such as, those most likely to be informative etc.) to be targeted for these more time-intensive research phases (Axinn & Pearce, 2006). Choosing the Data Types Each type of data included in this research was chosen deliberately. Phase 1 and 2 of the project used postal questionnaires, which have the advantage of being able to easily assess a large number of respondents simultaneously (Axinn & Pearce, 2006). Questionnaires also allow the use of standardised measures which can facilitate the comparison of data between studies. Since one of the aims of this study is to provide Australian data on concepts that may be comparable to other populations, it is vital to use approaches that are consistent with those used in previous research. In addition, as this is the first time that Gatchel’s Model has been examined with a community sample of people with pain, standardised questionnaires provide a precedent against which to compare these data. However, questionnaires and standardised instruments are limited in their ability to provide in-depth information about new concepts and processes because the research questions and the measures that are used to assess these questions are set a priori (Axinn & Pearce, 2006). Due to the structure of questionnaires, participants’ responses are constrained to factors predetermined by the researcher – who cannot predict the total experience of their participants. While quantitative research reduces the variability in a phenomenon to highlight patterns across that phenomenon, as a result of the reductionist nature of this type of research, some of the fullness of the experience may be lost, for example, when using standardised items (Axinn & Pearce, 2006). Chapter 3: Methodology of the Research 66 To overcome some of the limitations of questionnaires, semi-structured interviews were utilised. The interviews were designed to allow new themes to emerge as well as exploring the processes underlying the experience of pain. This type of qualitative data collection has the potential to provide greater opportunities for insight into the lives of the target population, and opportunities for new discoveries. Given that this research aimed to extend Gatchel’s Model to include concepts (e.g., protective factors) not frequently studied in previous pain research, this approach was considered particularly important. The limitations of semi-structured interviews also need acknowledgement. This method is time and labour intensive for the researcher and participant. As well, this type of data collection may be more confronting for participants who are disclosing their personal experiences face-to-face with the interviewer. In addition, similar to questionnaire methods, bias may be introduced through the wording or order of items as well as through the interaction between the interviewee and interviewer (Axinn & Pearce, 2006). In order to minimise bias in this research, consistent wording was used for the primary interview questions and some optional prompts. Questions were also administered in the same order by one interviewer. In addition, by emphasising at the beginning of each interview the importance of each participant’s beliefs, opinions and experiences, the interviewer tried to create a similar context for all participants, one in which their individual experiences were valued and welcomed. Matching a Mixed-Methods Approach to Chronic Pain Research In addition to selecting the type of data collection that would be undertaken at each research phase, there were several topic-specific reasons for choosing to use Chapter 3: Methodology of the Research 67 a mixed-method design. Mail questionnaires were used to obtain a snapshot of the experience of pain in a large community sample, and to allow comparison with previous literature. In this research postal questionnaires allowed a random sample of Queensland residents to be targeted in order to be able to generalise the findings to a broad groups of people with pain. The value of including qualitative methods is that it allowed the experience of pain, a subjective experience, to be explored in an experiential way. As relatively little research has examined the perceptions of those with pain in this way (for exceptions see Campbell & Guy, 2007; Corbett, Foster, & Ong, 2007; J. C. Richardson, Ong, & Sim, 2006) and more often with women only (e.g., Johansson, Hamberg, Westman, & Lindgren, 1999; Werner, Isaksen, & Malterud, 2004) or clinical patients only (e.g., Johansson et al., 1999; J. Walker, Holloway, & Sofaer, 1999), key information may be missing from our understanding of pain. In addition, one of the strengths of qualitative research is its ability to explore processes such as those involved Gatchel’s Model, which the questionnaire data may be less able to address. Optimising the Use a Mixed-Methods Approach There are a number of strategies that have been identified which may optimise the use of a mixed-method approach. Axinn and Pearce (2006) highlight the importance of using complementary methods to offset each methods’ weaknesses, for example, choosing a mix of highly- and less-structured techniques or methods which involve direct and indirect participant contact. Additionally, five aspects for consideration when designing well integrated mixed-method studies were emphasised by Yin (2006), and these factors were considered in the design of this research. First, the research question and studies are Chapter 3: Methodology of the Research 68 integrated; each study should contribute to all research questions. In the current research, Phases 1 and 3 will examine the first aim and Phases 1, 2 and 3 will target the second aim. Second, the studies use the same unit of analysis. In this research, each of the research phases employed participants from one community sample (that is, a single unit of analysis). Third, in addition to using the same unit of analysis, it may be desirable to use nested samples. A nested sample is when a sample for one data collection is a sub-sample of another data collection. In the current research, a large sample is used for the questionnaire phases and a smaller subset of the original sample is used in the interview phase. Fourth, overlapping or complementary instrumentation and data collection methods may allow each of the different approaches to confirm the findings of the other. In this study, some items were used in all data phases to better understand how participants interpreted these example items. A related issue in longitudinal research is the issue of repeated measurement (Axinn & Pearce, 2006). It is vital to use the same measures to allow changes in these constructs to be assessed and reduce bias associated with changes to measurement technique. Finally, the purpose of the different analyses should be matched across the different types of data. Therefore the findings of each study in this research will be additive and contribute to the overall research aims. Description of the Study Methodology Design Data were collected using a prospective mixed-methods design. In the first data collection phase, quantitative data was collected using questionnaires (hence referred to as the baseline study). The second research phase again used questionnaires and quantitative data (hence known as the follow-up study). The third Chapter 3: Methodology of the Research 69 data collection phase employed semi-structured interviews to obtain qualitative data (hence called the interview study). See Figure 2 for an illustration of the samples and study design. Phase 1 Questionnaires posted No response received Returned questionnaires Pain-free participants Acute pain participants Intermittent pain participants Follow-up questionnaire posted Chronic pain participants Follow-up questionnaire posted Lost to follow-up Lost to follow-up Phase 2 Returned follow-up questionnaires Returned follow-up questionnaires Invitation for interviews made Invitation for interviews made Lost to follow-up Lost to follow-up Phase 3 Interviews conducted Interviews conducted Figure 2. Flowchart of the study sample Sample Across Queensland, Australia, a community sample of people with pain was targeted. Using the same methodology, demographic variables were also collected from participants with no pain. Ten postcode areas were randomly selected; one from each of the six shires or cities from the greater Brisbane area (the most densely populated metropolitan area in Queensland (Department of Local Government Planning Sport and Recreation, 2005)) and one each of the other four remoteness Chapter 3: Methodology of the Research 70 classifications, defined using the Accessibility/ Remoteness Index of Australia (Australian Department of Health and Aged Care, 1999)10. Postcodes were drawn out of a hat containing all the postcodes of the region or remoteness classification. Table 3 displays the probability for the selection of each of the targeted postcodes. Within each of the 10 randomly selected postcode areas, 800 residential addresses were further randomly selected to receive the mailed questionnaire11. Table 3 Probability of Postcode Selection Selected postcode 4053 4020 4129 4507 4164 4105 4717 4725 4741 4869 Region Pine Rivers shire Redcliffe city Logan city Caboolture shire Redland shire Brisbane city Blackwater town Barcaldine town Mackay region Cairns city Probability of selection 1 in 12 1 in 4 1 in 16 1 in 12 1 in 10 1 in 163 1 in 42 1 in 48 1 in 53 1 in 58 Note. A postcode list was not available for Brisbane City. Instead, a Statistical Local Area (SLA: a category used by the Australian Bureau of Statistics) was randomly chosen from the 163 SLAs in the Brisbane City. The corresponding postcode for this SLA is 4105. Survey recipients experiencing pain were asked to provide their postal address and contact telephone number if they consented to participate in the followup components of this study. Participants with pain, who consented to be recontacted, were then invited to participate in the follow-up study. Participants of the follow-up study could nominate to be contacted for the interview study. 10 This index classifies geographical locations based on accessibility to services. One district had only 696 postal addresses; therefore less than 800 residential addresses were targeted. 11 Chapter 3: Methodology of the Research 71 Procedure Phase1: Baseline Study The questionnaire packs (N = 7896) were mailed through the Unaddressed Mail Service12 of Australia Post to residents of the selected Queensland postcodes. The information sheet and questionnaire instructions requested any adult (18+ years) experiencing significant pain in the household to complete the questionnaire. Participants were requested not to respond if their pain related to a diagnosis of, or treatment for, cancer13. Significant pain was defined as pain that had lasted more than a 24-hour period in the previous fortnight14. To obtain comparative demographic information for those without pain, if no one was experiencing significant pain, one adult member of the household was requested to complete the demographics section only and return the questionnaire. The use of identification numbers assigned to returned questionnaires enabled the respondent data to be matched across the data collection points. A record of returned questionnaires’ identification numbers plus contact details was made (in order for a corresponding identification number to be pre-printed on the follow-up questionnaire). Phase 2: Follow-up Study Baseline respondents who experienced acute or chronic pain were sent the same questionnaire for a second time (N = 302). The follow-up questionnaires were sent 12 weeks after the distribution of the baseline questionnaires, the length of time 12 The unaddressed mail service delivers unaddressed mail to all or a random selection of residential addresses in a chosen postcode delivery area. 13 Unlike other musculoskeletal pain, cancer pain can be a result of the disease or treatment (Jay et al., 1986) and is associated with different pain cognitions compared with those with non-cancer pain (de Wit, van Dam, Litjens, & Huijer Abu-Saad, 2001). 14 Fourteen days was chosen as the window for experiencing pain as this was considered a reasonable length of time to be able to recall a serious pain event and also to increase the number of eligible participants for the study. This criterion has previously been used and found to be acceptable in population based studies (e.g., Benjamin et al., 2000). Data are collected on the number of days the participant has experienced pain. Chapter 3: Methodology of the Research 72 that differentiates between acute and chronic pain (see IASP, 1986 for the definition). Phase 3: Interview Study Follow-up respondents, who indicated interest in being involved in the final stage of this research, were invited to participate in semi-structured interviews (N = 41). Due to logistical reasons, only respondents living in the greater Brisbane area were contacted for interviews because these were conducted face-to-face. (When compared, the urban and rural participants who were available for the interview study did not differ on depression, anxiety, pain intensity or disability scores; see Appendix A for these analyses). Interviews were held approximately 12 months (between 10-14 months) after the follow-up study. This was because some evidence suggests that back pain in particular fluctuates over time (Burton et al., 1995). Twelve months was considered a sufficient time to capture some of these fluctuations. Ethical Clearance and Occupational Health and Safety Approval The study was approved by the University Human Research Ethics Committee (approval number: 0600000252). For the questionnaire phases (baseline and follow-up) written consent was assumed if participants returned a completed questionnaire. Consent was given to use the data in the thesis in an aggregate form to preserve anonymity. For the interview phase, written consent was obtained prior to commencing the interviews. Consent was obtained to audiotape and transcribe the interview, and to use the information provided in the thesis anonymously. Chapter 3: Methodology of the Research 73 Occupational health and safety approval was obtained to conduct this project through the School of Psychology and Counselling. Measures Questionnaire: Phase 1 (baseline) After consideration of the key concepts of Gatchel’s Model and the noted risk and protective factors, an extensive test battery was compiled. This test battery included 12 established self-report instruments chosen to reflect the four keys areas of study within this research, the first two of which are components of Gatchel’s Model: pain severity and disability (physical de-conditioning), psychological distress (mental de-conditioning), risk factors and protective factors. Figure 3 illustrates the instruments used to operationalise Gatchel’s de-conditioning concepts and Table 4 matches the risk and protective factors under investigation with the standardised instruments used to assess those concepts. Demographic information was collected at baseline only. Items that assessed pain variables were included so that a description of this sample’s pain experience could be provided (see Appendix B for a copy of the questionnaire). A small pilot study was conducted to assess the readability and ease of comprehension of the questionnaire. Four adults with pain completed the questionnaire. The entire measure took approximately 30 minutes to complete. Several minor aesthetic changes were made to the layout of the items as a result of feedback from these participants. Chapter 3: Methodology of the Research 74 PHYSICAL DECONDITIONING Graded Chronic Pain Scales Roland & Morris Disability Questionnaire MENTAL DECONDITIONING Center for Epidemiologic Studies-Depression Pain-related Anxiety Symptoms Scale PAIN (Hurt = Harm) STAGE 1 Initial psychological distress (fear, anxiety, worry etc) STAGE 2 Development or exacerbation of psychological problems STAGE 3 Acceptance of “sick role”; consolidation of abnormal illness behaviour Figure 3. Mapping the measures onto Gatchel’s Model Table 4 Mapping the Risk and Protective Variables onto the Questionnaire Measures Variable Under Investigation Measure Risk factors Acute pain severity Pain intensity subscale of Graded Chronic Pain Scales Belief: likelihood of recovery from pain Single item from the Fear-Avoidance Beliefs Questionnaire Catastrophising Subscale from Coping Strategies Questionnaire Fear-avoidance beliefs Fear-Avoidance Beliefs Questionnaire Gender Single demographic item Age Single demographic item Protective factors Coping strategies Subscales from Coping Strategies Questionnaire Subscales from Chronic Pain Coping Inventory Self efficacy Pain Self Efficacy Questionnaire Beliefs about pain Survey of Pain Attitudes Positive affect Positive Affect scale of the Affect Balance Scale Optimism Life Orientation Test - Revised Social support Multidimensional Scale of Perceived Social Support Chapter 3: Methodology of the Research 75 The following sections describe each of the established instruments included in the questionnaire. The rationale for their inclusion in this research is also provided. Experience of Pain and Disability Pain and disability variables were examined using the Graded Chronic Pain Scales (GCPS) and the Roland and Morris Disability Questionnaire (RMDQ). These measures provided a proxy measure of disability and therefore physical deconditioning. Graded Chronic Pain Scale In addition to physical de-conditioning, the Graded Chronic Pain Scale (GCPS) also provided a measure of pain intensity, a factor that needed to be controlled, and also allowed the pain experience of a community sample to be charted. Thus, the GCPS was used because it provides a comprehensive measure of the severity of chronic pain that accounts for level of pain and the associated disability. The GCPS contains seven items which form a pain intensity estimate and a disability estimate appropriate for epidemiology studies (Von Korff et al., 1990; Von Korff, Ormel, Keefe, & Dworkin, 1992). The combination of the pain intensity and disability estimates are used to categorise individuals with pain into four severity grades – I low disability-low intensity; II low disability-high intensity; III high disability-moderately limiting; IV high disability-severely limiting. The grade is given based on the level of pain intensity and a disability score (see Von Korff et al., 1992). However, pain intensity and disability scores provide an alternate continuous variable for analyses where categorical variables are inappropriate. This Chapter 3: Methodology of the Research 76 measure was designed to be able to be used with people with pain at all anatomical sites resulting from a variety of causes (Von Korff et al., 1992). GCPS scoring is calculated in several phases. The pain intensity estimate is the average of the scores for current, worst and average pain and transformed into a score from 0 to 100. The disability estimate is scored as the average of interference with daily activities, social activities and work activities, measured from 0 to 100. Then a disability days score is assigned (from 0-3) based on the activity limitation days item. As participants were asked about the previous 3 months, their activity limitation days response was multiplied by 2 before calculating the disability days score (Von Korff, 2001)15. The GCPS was normed on general population and primary care samples. It has good internal consistency seen across a range of pain and general practice populations, for example, ranging from .62 to .80 for temporomandibular disorder pain to .73 to .79 for headache (Underwood, Barnett, & Vickers, 1999; see also Von Korff, 2001 for a review; Von Korff et al., 1990; Von Korff et al., 1992). Good testretest reliability (≥.82) has been reported in community samples (Underwood et al., 1999). Roland and Morris Disability Questionnaire To improve the concurrent validity of this study, the Roland and Morris Disability Questionnaire (RMDQ) was chosen as a second measure of disability because self report instruments are only proxy measures of physical de-conditioning. The RMDQ is an established and widely used measure of disability. It is a quick 24item measure designed to be completed without assistance from medical personnel 15 Using a 3-month period may result in higher ratios of grade III & IV classifications (Von Korff, 2001). Chapter 3: Methodology of the Research 77 in approximately 5 minutes (Roland & Morris, 1983a, 1983b). The RMDQ was originally developed to measure disability associated with back pain. However, consistent with other researchers (Jensen, Keefe, Lefebvre, Romano, & Turner, 2003), the questionnaire was modified to be appropriate for all musculoskeletal pain conditions by replacing the word ‘back’ with the word ‘pain’. Responses are scored as 0 (did not apply) or 1 (true). The total score indicates the level of disability severity with higher scores reflecting greater pain disability (range 0-24). The RMDQ has good test-retest reliability (Roland & Morris, 1983a). Internal consistency was excellent (α = .96) in a community pain sample (Underwood et al., 1999). Psychological Distress Variables Two instruments that examine two common psychological distress factors were used to examine depressive symptoms (Center for Epidemiologic Studies Depression scale; CES-D) and pain-related anxiety (Pain Anxiety Symptoms Scale; PASS). These were used to operationalise mental de-conditioning syndromes. Center for Epidemiologic Studies Depression scale Depression is commonly seen in pain patients and was recognised by Gatchel as a common expression of mental de-conditioning; therefore a measure of depressive symptoms was used in this research. The Center for Epidemiologic Studies Depression scale (CES-D Scale) is a 20-item measure of self-reported depressive symptoms (Radloff, 1977). It was developed for use with the general population. Respondents mark the frequency of their feelings or behaviour on a 4- Chapter 3: Methodology of the Research 78 point likert scale ranging from rarely or none of the time to most or all of the time. Each point on the likert scale is anchored to a verbal descriptor. Of all the depression measures available, the CES-D was selected because it has often been used in pain research, particularly with non-clinical samples (e.g., Fritz et al., 2001), and also because it was developed for use with the general population in epidemiology-type studies (similar to the current study). CES-D scores are summed; higher total scores reflect more frequent depressive symptoms with a range from 0 to 60. In the general population cut-off scores have been developed to differentiate people with significant depressive symptoms. Due to the overlap between depressive symptoms and symptoms of pain (such as sleep disturbance), a higher cut-off score is required to detect people with pain who have significant depressive symptoms (Geisser, Roth, & Robinson, 1997). The optimal cut-off score is 27, which is used a proxy measure of depression. The CES-D is a popular measure of depressive symptoms (Santor, Zuroff, Ramsay, & Cervantes, 1995). It has good internal consistency, between .85 and .90 (Radloff, 1977). The CES-D has moderate test-retest reliability, which is not unexpected given the changing or cyclic nature of some depressive symptoms (Radloff, 1977). Pain Anxiety Symptoms Scale-20 Another common form of mental de-conditioning is pain-related anxiety. The Pain Anxiety Symptoms Scale (PASS) is a measure that targets four areas of pain anxiety: somatic anxiety, cognitive anxiety, fear, and escape/ avoidance responses (McCracken, Zayfert, & Gross, 1992). A 20-item version is available (McCracken & Dhingra, 2002), which was used in the current study. The PASS was Chapter 3: Methodology of the Research 79 chosen as the measure of anxiety for this study primarily because it is a measure that is specific to pain; Gatchel’s Model suggests that the anxiety experienced by people as they develop chronic pain is pain-related. In addition, compared to general measures of anxiety, pain-related measures have been found to explain more variance in pain and pain-related disability (McCracken, Gross, Aikens, & Carnrike, 1996). The PASS is a measure that has been previously used with community pain samples also (Abrams, Carleton, & Asmundson, 2007; Coons, Hadjistavropoulos, & Asmundson, 2004). In the 20-item version of the PASS (PASS-20), each subscale is represented by five items. Respondents are instructed to rate the frequency of the behaviour detailed in each of the items; response options range from 0 (never) to 5 (always). Responses are summed to calculate a total score (range 0-100) (McCracken & Dhingra, 2002). As in previous research (Crombez et al., 1999; McCracken et al., 1996), the total score was used in this study. A cut-off score of 30 is suggested to identify individuals with high pain-related anxiety (Abrams et al., 2007). The PASS-20 correlates strongly with the full-length PASS (McCracken & Dhingra, 2002). In addition, the psychometric properties of the PASS-20 have been specifically examined in a number of studies (Abrams et al., 2007; Coons et al., 2004; McCracken & Dhingra, 2002). Factor analysis of the items consistently demonstrates a 4-factor solution consistent with the development of the scale. Internal consistency ranges from .70 to .87 for the subscales and .83 to .91 for the total scale. The PASS-20 is regarded as having good construct and predictive validity (Abrams et al., 2007; Coons et al., 2004; McCracken & Dhingra, 2002). Chapter 3: Methodology of the Research 80 Extensions to Gatchel’s Model: Risk Factor Variables As this research aimed to examine possible extensions of Gatchel’s Model, concepts identified as risk factors for either developing a pain condition or for worse pain-related disability outcomes were assessed (see Chapter 2 for more information). Fear-avoidance beliefs were examined as a possible risk factor for increasing disability and de-conditioning using the Fear-Avoidance Beliefs Questionnaire (FABQ). The Coping Strategies Questionnaire (CSQ) was used primarily to examine the influence of catastrophising as a risk factor and as a possible valuable addition to Gatchel’s Model. Fear-Avoidance Beliefs Questionnaire The Fear-Avoidance Beliefs Questionnaire (FABQ) is a 16-item questionnaire originally designed to measure fear-avoidance beliefs about work (11 items) and physical activity (5 items) for back pain (Waddell, Newton, Henderson, Somerville, & Main, 1993). It is frequently used in pain research (e.g., Ciccone & Just, 2001; Crombez et al., 1999; Fritz et al., 2001). The FABQ was selected for this research because it measures fear-avoidance beliefs specific to two areas (that is, physical activity and work) that are noteworthy in terms of the impact on one’s daily life (Nagi, 1976) and are most affected by fear-avoidance type beliefs (Waddell et al., 1993). Again, compared to general measures of fear, pain-specific fear measures have stronger relationships with pain and pain-related disability (McCracken et al., 1996). Each item is responded to on a 7-point likert scale, anchored at each end with strongly agree and strongly disagree. Higher scores reflect stronger fear-avoidance beliefs. Chapter 3: Methodology of the Research 81 Factor analysis reveals two factors, on which only 11 items robustly load – 7 items on beliefs about work and 4 items on beliefs about physical activity. Only the 11 items that load on these factors are scored and summed. For this study, one additional item was included from the FABQ that reflects the belief that they will return to work. This additional item was included in the questionnaire because patients’ beliefs that they will recover are predictive of the development of chronic pain (Linton & Hallden, 1997; Schultz et al., 2004; White et al., 1997). The instructions for the FABQ were modified slightly in this research to reflect that research participants are not patients. Adults whose primary occupation is homemaker were instructed to consider these duties their ‘work’ as suggested by Waddell et al. (1993). Like the Roland and Morris Disability Questionnaire, the items were modified to reflect the variety of pain complaints that respondents had by removing the word ‘back’ from the instructions, and items 3 and 11. The FABQ has good test-retest reliability (Waddell et al., 1993). The internal consistency for the FABQ work subscale is good, ranging from α = .82 to .92 in chronic pain patient samples (e.g., Ciccone & Just, 2001; Crombez et al., 1999; Waddell et al., 1993) and .74 in acute pain patient samples (Ciccone & Just, 2001). However, the internal consistency of the FABQ physical activity subscale is poorer, ranging from .52 to .77 (Crombez et al., 1999; Waddell et al., 1993). While the scales were derived using factor analysis with an orthogonal rotation (Waddell et al., 1993), the scales have since been reported to correlate positively (r = .47-.55) (see Crombez et al., 1999; Fritz et al., 2001). Chapter 3: Methodology of the Research 82 Coping Strategies Questionnaire The Coping Strategies Questionnaire was originally developed by Rosenstiel and Keefe (1983) with low back pain patients. It consists of seven theoretical subscales; diverting attention, reinterpreting pain sensations, catastrophising, ignoring sensations, praying/ hoping, coping self-statements, and increased activities. With the exception of the increased activities subscale, the CSQ examines cognitive coping strategies. Each of the seven scales consists of six items. There are an additional two items that examine the effectiveness of the coping strategies to 1) control, and 2) reduce pain. The robustness of the structure of the CSQ has been debated (Swartzman, Gwadry, Shapiro, & Teasell, 1994) and some subscales (i.e., ignoring sensations and increased activities) have weak reliability. This measure was chosen specifically for the catastrophizing subscale, as catastrophizing is a variable that is associated with poorer outcomes for chronic pain patients (see Hadjistavropoulos, MacLeod, & Asmundson, 1999; Keefe et al., 2004). Catastrophising may be a useful extension to Gatchel’s Model as a risk factor. CSQ responses scored on 7-point likert scale from 0 (never) to 6 (always). Item scores are averaged to calculate subscale scores. Internal reliability scores range from .71 to .85 (Rosenstiel & Keefe, 1983). Test-retest reliability of the original scale ranged from .68 to .93 in a sample of low back pain patients. The catastrophizing subscale has the overall strongest statistical properties (Main & Waddell, 1991; Swartzman et al., 1994). Jensen et al. (2003) developed a shorter scale with two items per each of the seven subscales. Correlations for each short subscale with the parent scale averaged .87. Similarly, relationships between the short subscale and measures of depression, disability and pain rating replicated the relationships between the parent scale and Chapter 3: Methodology of the Research 83 these measures 86% of the time. Tan, Nguyen, Cardin, and Jensen (2006) replicated the results of Jensen et al. in terms of the level of association with the parent scale (ranged from .81 to .86) and construct validity. Due to the already lengthy nature of the questionnaire and the excellent statistical proprieties reported by Jensen et al. and Tan et al., the short CSQ version was used in this research. Extensions to Gatchel’s Model: Protective Factors Chronic Pain Coping Inventory Protective factors that may reduce or slow the onset of disability and deconditioning were of particular interest in this research (see Chapter 2). One inventory that examines multiple coping strategies is the Chronic Pain Coping Inventory (CPCI). The CPCI is a 65-item measure developed by Jensen, Turner, Romano and Strom (1995). There are eight subscales – guarding, resting, asking for assistance, relaxation, task persistence, exercise/ stretch, seeking social support and coping self-statements. The CPCI allows a number of specific strategies to be examined rather than more generic active vs. passive strategies. The subscales evaluate strategies that are likely to be addressed in a specialist pain clinic program. Four of the subscales target strategies that would be encouraged in a specialist pain clinic program - relaxation, task persistence, exercise/ stretch, and coping selfstatements. Three of the subscales target strategies that would be discouraged guarding, resting, asking for assistance. Seeking social support is considered a neutral subscale (see Hadjistavropoulos et al., 1999). In contrast to the Coping Strategies Questionnaire, the CPCI is a measure of primarily behavioural coping strategies. Chapter 3: Methodology of the Research 84 CPCI items are measured on an 8-point likert scale by asking respondents to nominate how many days in the previous week each item (strategy) was used. Scores are averaged to provide scale scores. Internal consistency estimates for the scales range from .70 to .93 (Jensen et al., 1995). Test-retest reliabilities, over a fortnight, range from .66 to .90 (Jensen et al., 1995). A shortened version of the CPCI was developed; containing only 42 items (Romano, Jensen, & Turner, 2003). A further shortened version of this measure using only two items for each of the subscales was subsequently developed (Jensen et al., 2003). Each of the subscales for the 16-item version correlates strongly with each of the parent subscales (Jensen et al., 2003). The test statistics for the shortened version are good to excellent and have been replicated in other populations (Tan et al., 2006). Tan and colleagues reported the association with the parent scale .75 to .91 for each of the subscales. The 16-item CPCI version was used in this study. Survey of Pain Attitudes Like the Chronic Pain Coping Inventory, the Survey of Pain Attitudes (SOPA) is an established measure of a range of attitudes that are thought to be important for people with chronic pain. Pain beliefs are considered as an extension to Gatchel’s Model. Since an early version of this measure was used by Jensen and Karoly (1991) in their work on beliefs and chronic pain, the SOPA has undergone a number of revisions (see Jensen, Karoly, & Huger, 1987; Jensen, Turner, Romano, & Lawler, 1994; Strong, Ashton, & Chant, 1992). The most-well known and utilised version has 57 items. The SOPA measures seven beliefs about pain – personal control over pain, appropriateness of solicitous responses from family, Chapter 3: Methodology of the Research 85 appropriateness of medications for chronic pain, inability to function, relationship between pain and emotion, medical cure exists for pain problem, and pain signifies harm (Jensen et al., 1994). Responses are given on a 5-point likert scale. Each point on the scale is anchored with a verbal description, for example, a score of 3 = This is somewhat true for me (Jensen et al., 1994). After calculating reverse-scored items, the average of each subscale is derived. Each of the belief scales has adequate statistical properties. Cronbach’s alpha ranges from .71 to .81 (Jensen et al., 1994). Test-retest reliability estimates range from .63 to .68 for each of the scales (Jensen et al., 1994). Like the Chronic Pain Coping Inventory, a 14-item version of the SOPA (with each scale represented by two items) has been developed. This shorter version was used in this study. Each of the subscales for the shortened SOPA correlates strongly with the corresponding parent subscale (Jensen et al., 2003; Tan et al., 2006). Pain Self efficacy Questionnaire Self efficacy has been identified as an important factor in managing chronic pain and is associated with pain-related disability; it may be protective during the acute to chronic pain transition. The Pain Self efficacy Questionnaire (PSEQ) is a 10-item measure of self efficacy (Nicholas, 2007). It was chosen for this research because it was originally developed for, and has been subsequently used in, Australian samples (Gibson & Strong, 1996; Nicholas, Wilson, & Goyen, 1992). Also, the PSEQ focuses on the respondent’s confidence that they can engage in certain activities despite pain. Chapter 3: Methodology of the Research 86 PSEQ items are scored on a 7-point likert scale, from 0 (not at all confident) to 6 (completely confident). Item scores are summed to provide a total score (range 0-60); higher scores reflect higher self efficacy to function despite pain. In terms of norms, the mean score in a rehabilitation setting was 36 (Gibson & Strong, 1996). The mean scores for chronic pain patient samples were: pre-treatment range 23-28 and post-treatment range 31-32 (Frost, Lamb, & Shackleton, 2000; Nicholas, 2007; Nicholas et al., 1992; Strong, Westbury, Smith, McKenzie, & Ryan, 2002). The PSEQ has been used by many researchers, who report good reliability and validity estimates for the questionnaire (Nicholas, 2007). In previous Australian research, internal consistency ranges from .92 (Asghari & Nicholas, 2006; Strong et al., 2002) to .94 (Gibson & Strong, 1996). Test-retest reliability is reported to be .73 over 3 months (Nicholas, 2007). The PSEQ has been used as an outcome measure in the treatment of chronic pain patients (Nicholas et al., 1992) as well as a predictive measure of other treatment outcomes (Strong et al., 2002). Positive affect scale of the Affect-Balance Scale As discussed in Chapter 2, positive affect is a further possible protective factor. The Affect-Balance Scale is a 10-item established measure of positive and negative affect (Bradburn, 1969), which has been used with people with rheumatoid arthritis (Revenson & Felton, 1989). It was chosen for this reason. Five items reflect positive affect. Items are answered yes or no. Affirmative responses are scored 1. The scores of each item are summed for total score. Scores range from 0 to 5; higher scores reflect greater positive affect. Internal consistency at two time points ranged from .71 to .72 (Revenson & Felton, 1989). Chapter 3: Methodology of the Research 87 Life Orientation Test – Revised Optimism was identified as a possible protective factor in Chapter 2. The Life Orientation Test – Revised (LOT-R) is a 10-item measure of optimism that focuses explicitly on expectancies for the future (Carver & Scheier, 2003; Scheier, Carver, & Bridges, 1994). The LOT-R was included in this research because it is a well-used measure of optimism in health research and has been used with chronic pain patient samples previously (Cannella et al., 2007). The LOT-R uses 3 negatively worded and 3 positively worded items that contribute to the scale as well as four filler items. Participants indicate on a 5-point likert scale their level of agreement with each item; from strongly disagree to strongly agree. All points of the likert scale are anchored with a description, for example, a score of 1 corresponds with disagree. Negatively worded items are reversed scored prior to summing the scores to produce a total score (range 0-24). Internal consistency statistics for the LOT-R are acceptable at .78 (Scheier et al., 1994). Multidimensional Scale of Perceived Social Support Perceived social support, a potential protective factor, was assessed using the Multidimensional Scale of Perceived Social Support (MSPSS). The MSPSS was included in this research to overcome the limitations of single item measures of social support that have been often used in pain research. The MSPSS has 12 items, measured on a 7-point likert scale with anchors at each end from very strongly disagree to very strongly agree (Zimet, Dahlem, Zimet, & Farley, 1988). Items are averaged to provide a total score, which ranges from 1 to 7. Internal reliability of the scale is good; cronbach’s α ranges from .88 (Zimet et al., 1988) to .93 (Osborne, Chapter 3: Methodology of the Research 88 Jensen, Ehde, Hanley, & Kraft, 2007). Test-retest reliability over 2-3 months is also good (r = 0.85) (Zimet et al., 1988). Questionnaire: Phase 2 (follow-up) The questionnaire used during Phase 2 incorporated some of the previously described standardised measures. These included the Graded Chronic Pain Scales, Roland and Morris Disability Questionnaire, Center for Epidemiologic Studies – Depression scale and the Pain Anxiety Symptoms Scale. Semi-structured Interview: Phase 3 Semi-structured interviews were conducted between 10-14 months after Phase 2 (follow-up study) data collection. Twenty participants, recruited from the greater Brisbane area and who had consented follow-up contact, attended the interviews. Interviews were scheduled at the interviewees’ convenience. In the main, interviews were held in either small function rooms at public libraries located in the general vicinity of participants’ homes or in a university meeting room if the university campus was closer to the participant’s home than the local library. The choice of interview location used in this study was intended to facilitate participation since ensuring that research involvement is easy for interviewees can increase the willingness of potential interviewees to be involved (Axinn & Pearce, 2006). One interview was conducted in the participant’s home (sitting room) because he was unable to access either of these public venues due to limited availability of public transport. In all cases, only the researcher and interviewee were present. Private rooms were chosen to offer participants confidentiality during the interview, to minimise distractions, and reduce extraneous Chapter 3: Methodology of the Research 89 noise to improve the audio recording. In addition, the use of a neutral zone to conduct interviews may make it easier for participants to discuss sensitive topics (Axinn & Pearce, 2006); as noted above this occurred in all but one case. In preparation for the interview, the interviewees’ questionnaires were reexamined by the researcher. Reviewing this data was intended to assist in rapport development between the interviewer and interviewee, to allow the interviewer to provide prompts if necessary and in order for the interviewer to be sensitive to the site of pain, the severity of pain and any psychological distress that the respondents had reported previously (see Axinn & Pearce, 2006). Consideration of this data was found to be particularly helpful during the interviews with participants whose pain had resolved. Prior to beginning the interview, participants were provided with an information sheet detailing the expectations and requirements for the study. It was emphasised to participants that there were no right or wrong answers, and that the aim of the interviews was to obtain their opinions and thoughts (whatever they may be). Questions for the semi-structured interviews were generated from Gatchel’s Model and the Phase 2 questionnaire data. The interview questions were designed to be open-ended. Additional prompts were used to elicit greater description of, or to clarify, information provided by interviewees. To begin the interview, participants were asked to describe their pain experience. This question acted as a warm-up item and also encouraged participants to provide the salient points of their pain experience from their point of view. Subsequent questions targeted interviewees’ experiences of aspects of Gatchel’s Model (e.g., how did the pain affect you emotionally?), reasons for the development Chapter 3: Methodology of the Research 90 of chronic pain (e.g., some people’s pain does get better and some people’s pain doesn’t get better; why do you think that is?), and strategies to manage or prevent chronic pain disability (e.g., what do you think is the best way to deal with pain?). At the conclusion of the interview, participants were given the opportunity to comment on or re-emphasise any aspect of pain that they thought was important (which the researcher should know). The questions used in the semi-structured interviews can be found in Table 5. Prior to beginning the interviews, the first four participants were considered a pilot group, with which to trial the questions with members of the target group. (This number was arbitrarily chosen, based upon the timing of the scheduled interviews). By chance, these participants had all been classified as having continuing chronic pain in Phase 2. At the conclusion of each of these interviews, the researcher explored each question in terms of three aspects; clarity (i.e., whether the participant easily understood the question), openness of the response (i.e., whether the question elicited detailed responses/ data), and appropriateness and sensitivity of the terms used (i.e., whether the terms used fit well with the participant’s experience and were non-offensive). On the basis of these four pilot interviews and the subsequent reflection, one item was changed to improve the clarity of this question (see Table 5). An additional prompt was written for another question to reduce any offensiveness and to convey acceptance of participants’ experience (see Table 5). Interviews lasted between 25-95 minutes. Respondents whose pain had resolved generally had shorter interviews (range 25-69 minutes). Reflective listening techniques were used during the interviews to encourage continued narrative and to check for understanding. Chapter 3: Methodology of the Research 91 Table 5 Semi-structured Interview Questions Interview Items As a reminder to me, can you tell me about the pain you have/ had, how it started … that kind of thing? Why do you think you still have pain? / Why do you think you improved? How did/ do you cope with your pain? Is there anything that you think (thought) that helps/ ed you cope? Some people say that the way they feel can help them cope. What about your feelings – like your emotions – was there anything about them that helped you cope? What do you think is the best way to deal with pain? If you think back about when you first had pain … can remember when you first thought to yourself this isn’t going to get better? What was happening at that time? When on the time line? Was there something about your thinking that changed? How does pain get better or worse over time? a How did or does the pain affect you emotionally? For example, a couple of people that I have spoken with have said that they can get a bit grumpy when they’re in pain b Over time, did that get better or worse? How did or does the pain affect you physically? Over time, did that get better or worse? I have some statements that are from the questionnaire. The answers from all the people who completed the questionnaire were very different. I wondered if you could let me know what you think about them? 1. There is little that I can do to ease my pain 2. There is a connection between my emotions and my pain level 3. Exercise can decrease the amount of pain I experience Apart from your pain, have other things changed for you because of your pain? Has anything become better? Has anything become worse? Do you think that the type of person you are has changed because of your pain? What were you like before this pain started? Some people’s pain does get better, and some people’s pain doesn’t … why do you think this is? If you were asked to give some advice to someone who had the same kind of pain as you had, what would you tell them?? Note. Dot points denote additional prompts that may have been used. a Original item: How does pain change over time? How do you think pain is related to the passage of time? b This prompt was written as a result of the pilot interviews. Interviews were audio taped and subsequently transcribed verbatim, as soon as practicable, after the interview was conducted. Most interviews were transcribed by the interviewer; seven were transcribed by a transcription service. The seven Chapter 3: Methodology of the Research 92 transcripts (sent out for external transcription) were checked against the audiorecording for accuracy by the researcher. Analysis was considered as commencing with the first interview and continued in an ongoing fashion with subsequent interviews. As a result, after the first 20 interviews were conducted, because consistent issues emerged, it was judged that the breadth of the pain experience been had obtained (Morgan, 1998a). During the first 16 interviews, interviewees described new concepts. However, after this, no new information was forthcoming from the interviews. As no new information was probable in additional interviews, no further participants were contacted. Regardless, the final four interviews were completed and included in the data analysis as they had been already arranged with interviewees. Statistical Analysis Questionnaire: Phase 1 (baseline) & Phase 2 (follow-up) The questionnaire data was entered into a Statistical Package for the Social Sciences data file. Analyses were conducted using Statistical Package for the Social Sciences version 15.0. Unless stated, an alpha level of .05 was used. In most cases, imputation of missing quantitative data was performed (see Chapters 4-6 for further details). Data were screened for breaches of the assumptions of the statistical analyses undertaken and for univariate and multivariate outliers. Where breaches of assumptions occurred, these are detailed in the Results sections of Chapters 4-6. Chapter 3: Methodology of the Research 93 Semi-structured Interview: Phase 3 Interviews were transcribed verbatim. Interview transcripts were uploaded into NVivo version 7 for thematic analysis16. Chapter Summary A mixed-method approach was chosen for this research to utilise the strengths of each of the research types – questionnaires to examine Gatchel’s variables and the risk and protective variables using measures that allow comparison between the current data and previous studies; and semi-structured interviews to examine the experience of pain and transition to chronic pain from an individuals’ perspective using a method that allows greater opportunities for insight into the lives of target population. The procedure and results of the data analysis for Phase 1 are presented in Chapters 4 and 5, along with the purpose of this study and in this context, and a brief discussion of the results. Phases 2 and 3 are reported in Chapters 6 and 7, respectively. 16 Because the quantitative data informed the interview items and interpretation of the qualitative data, a grounded theory approach or phenomenological approach was not suitable for data analysis. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 95 CHAPTER 4: PHASE 1 – BASELINE QUESTIONNAIRES (Describing the community sample) Purpose of the Study The purpose of the baseline phase was to address both primary research aims. As discussed, the first aim was to obtain information on the nature of significant pain in a Queensland community sample as no large community painspecific studies have been conducted in Queensland previously. Given prevalence data internationally, and from New South Wales, it is likely that chronic pain will be a serious health problem in Queensland, and one that is associated with significant psychological distress, physical disability and healthcare costs. This study provided the opportunity to examine a broad range of pain conditions – heterogeneous in type and body site, as well as pain conditions that do not meet the criteria for chronic pain (e.g., episodic pain conditions). The data addressing the second aim, exploring Gatchel’s Model, is presented in Chapter 5. Brief Introduction Studies of community samples have found that chronic pain is not uncommon. For example, approximately 1 in 5 people in New South Wales report chronic pain (Blyth et al., 2001). Further, chronic pain in community samples interferes with activities of daily living (Blyth et al., 2001), results in greater use of healthcare services (Blyth et al., 2004), is associated with depressive symptoms (Breivik et al., 2006) and lower quality of life (Hoffman et al., 2002), and substantial work-related costs (increased absenteeism and workers’ compensation litigation, and Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 96 decreased productivity) (Blyth, March, Nicholas et al., 2003). These studies highlight the cost of chronic pain, even for people who do not present to a tertiary clinic setting. Missing from the research in this area is knowledge of the broader experience of pain, for example, the experience of chronic pain by groups not currently defined as “patients”, or people with longstanding intermittent pain. An examination of the total pain experience in the community (including acute pain) is necessary to map the pain trajectory across the whole spectrum of pain conditions; knowledge of which is important to inform treatment programs and the development of transitional models of acute to chronic pain such as those proposed by Gatchel (1991a). The study details the experience of pain in this community sample, including the influence of pain site, and the coping strategies used by a community sample. This chapter will focus on those people who meet the criteria for chronic pain, those who have intermittent pain, and those who describe an acute pain experience, as an important preliminary step to understanding the range of pain experienced in the Australian community and to inform transitionary process models of chronic pain. Method Sample As described in Chapter 3, 7896 questionnaires were sent out. Eight hundred and twenty-one questionnaires were returned. Of these, 20 were excluded from further analysis: six questionnaires were returned uncompleted, four questionnaires were completed by respondents under 18 years of age, one respondent nominated a New South Wales permanent address, and nine questionnaires had more than 50% Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 97 missing data. Removal of these cases resulted in 801 useable questionnaires; a response rate of 10.14%. The 801 respondents were classified into pain groups, corresponding to the pain definitions presented earlier (see Chapter 2). The process of defining pain groups is illustrated in Figure 4. Figure 4 shows that 348 participants were pain-free; these respondents will be known as the “pain-free sample”. Pain-free respondents provided demographic information only so that comparisons between their background characteristics and the other pain participants could be made. Four hundred and fifty-three respondents had significant pain. Of these, 55 participants reported more pain-free than pain-affected days; they will be referred to as the “intermittent subgroup”. There were 395 people who reported that they experienced this pain on more days than not. Three participants did not respond to this item, and were therefore excluded from subsequent analyses. Of the 395 respondents with pain on most days, 47 had acute pain (pain ≤ 3 months; hereafter called the acute subgroup) and 320 had chronic pain17 (pain > 3 months; hereafter called the chronic subgroup). There were also 28 respondents whose pain status could not be inferred because they did not report how long they had experienced their pain. Because 28 respondents did not report how long they had experienced their pain and could not be clearly assigned to either the chronic or acute pain groups, they were excluded from subsequent analyses. To determine if the exclusion of this group might have introduced sample bias, the demographic characteristics of this group was compared with the rest of the pain respondents; there were no differences 17 This represented 19.6% of the adults residing in the respondent households. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 98 801 completed questionnaires 348 pain-free 55 intermittent pain (more pain free days) 395 pain on most days 320 chronic pain 47 acute pain (pain most days >3mths) (pain most days ≤3mths) Figure 4. Defining the Phase 1 pain subgroups on gender, marital status, education level completed, age or number of adults in the household (the details of these analyses can be found in Appendix C). Therefore, there was no evidence that this excluded group differed from the rest of the sample. Measures Participants received a questionnaire that explored their experience of pain using the 12 measures described in Chapter 3, as well as demographic variables (age, gender, marital status, residential postcode, number of adults in household). Only the standardised measures that were used to describe respondents’ experience of pain are detailed here; the properties of which are presented in Table 6. Procedure One questionnaire pack was sent to approximately 800 randomly selected residential addresses in each of the 10 chosen postcode areas. Adults residing at targeted households were invited to participate through an information letter, which provided details of the study and ethical considerations (see Appendix D for a copy of the information sheet). A reply-paid envelope was provided in which to return Table 6 Description of the Measures used in Phase 1 to describe the Pain Experience of Respondents Instrument Graded Chronic Pain Scales (GCPS) Author Von Korff et al., 1990, 1992 Concept measured Pain Intensity Disability # items 7 Roland and Morris Disability Questionnaire (RMDQ) Roland & Morris, 1983a, 1983b Pain-related disability; daily interference 24 Center for Epidemiologic Studies Depression scale (CES-D) Radloff, 1977 Depressive symptoms 20 0-60; higher scores = greater depressive symptoms Cut-off score of 27 for depression in people with pain (Geisser et al., 1997) Pain Anxiety Symptoms Scale-20 (PASS-20) McCracken et al., 1992 Pain-related anxiety 20 0-100; higher scores reflect greater anxiety Cut-off score of 30 for high pain-related anxiety (Abrams et al., 2007) Coping Strategies Questionnaire (CSQ) short version Rosenstiel & Keefe, 1983 Jensen et al., 2003 14 0-6 for each subscale score Chronic Pain Coping Inventory (CPCI) - short version Jensen et al., 1995, 2003 Cognitive coping strategies: Reinterpreting pain sensations; Diverting attention; Ignoring sensations; Praying/ hoping; Coping selfstatements; Increased activities; Catastrophising Behavioural coping strategies: Guarding; Resting; Asking for assistance; Relaxation; Task persistence; Exercise/ stretch; Seeking social support; Coping self-statements 16 0-7 for each subscale score Survey of Pain Attitudes (SOPA) - short version Jensen et al., 1994, 2003 14 0-4 for each subscale score Attitudes associated with coping: Personal control over pain; Appropriateness of solicitous responses ; Appropriateness of pain medications; Inability to function; Relationship between pain & emotion; Medical cure exists for pain problem; Pain signifies harm Score range Pain intensity 0-100 Disability estimate 0-100 Four classification levels: I low disability-low intensity; II low disability-high intensity; III high disabilitymoderately limiting; IV high disability-severely limiting 0-24; higher score reflect greater disability Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 100 the completed questionnaire. Participants were offered an opportunity to be entered into a holiday draw on returning a completed questionnaire. Statistical Analysis Reliability analyses were conducted before missing data was imputed. These analyses were conducted in this order so that imputed values did not artificially increase the cronbach’s alpha18. Internal Consistency For the coping and attitude measures (i.e., CSQ, CPCI, SOPA), internal consistency was calculated for each subscale. As can be seen in Table 7, the internal consistency of each of the disability and psychological distress scales ranged from good to excellent. However, the internal consistency for subscales of the CSQ, CPCI, and SOPA was lower. This is likely to be because each of these subscales contained only two items. Due to the number of and the low reliability estimates for these subscales, only those subscales with an alpha ≥ .55 were used in the following analyses. Missing Data The data was examined for missing values. Scale items were examined for patterns of missing data. No patterns were identified. Missing data was minimal and random. If 70% of the items for a scale were available, missing data was replaced using an Estimated Maximisation technique for all baseline scale items, calculated scale by scale for pain respondents. (Pain-free respondents were not 18 Reliability analysis was re-run after missing values were imputed; the same alpha values were obtained. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) Table 7 Internal Consistency for each of the Scales and Subscales (N = 453) Scale/ Subscale α Graded Chronic Pain Scale Pain intensity .78 Disability Estimate .92 Center for Epidemiologic Studies - Depression .91 Pain Anxiety Symptoms Scale-20 .94 Subscales of the Coping Strategies Questionnaire: Diverting attention .75 Reinterpreting pain sensations .53 Catastrophising .68 Ignoring sensations .51 Praying/ hoping .42 Coping self-statements .54 Increased activities .42 Subscales of the Chronic Pain Coping Inventory: Guarding .62 Resting .63 Asking for assistance .80 Relaxation .57 Task persistence .76 Exercise/ stretch .59 Seeking social support .71 Coping self-statements .51 Subscales of the Survey of Pain Attitudes: Personal control over pain .25 Appropriateness of solicitous responses from family .67 Appropriateness of pain medications .46 Inability to function when in pain .67 Relationship between pain & emotion .71 Medical cure exists for pain problem .48 Pain signifies harm .11 101 Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 102 required to complete these measures). Table 8 displays the number of items and minimum number of items required in each scale for missing data to be replaced. As can be seen in Table 8, less than 3% of the data were imputed on any given scale. Table 8 Missing Data Imputed (n = 453) 7 Minimum # items required for imputation 5 # item replacements made 9 CES-D 20 14 67 0.74 Anxiety PASS 20 14 64 0.71 Coping strategies CPCI 16 11 97 1.34 Coping strategies CSQ 14 10 46 0.73 SOPA 14 10 59 0.93 Construct Scale # items Pain and disability GCPS Depression Pain attitudes % possible replacementsa 2.84 Note. GCPS: Graded Chronic Pain Scales, CES-D: Center for Epidemiologic Studies – Depression, PASS: Pain Anxiety Symptoms Scale, CPCI: Chronic Pain Coping Inventory, CSQ: Coping Strategies Questionnaire and SOPA: Survey of Pain Attitudes a % of possible replacements = (# replacements /N x # items in scale) x 100 Results The description of pain in this sample is presented in a number of sections. First, the demographic information for each of the pain subgroups is presented, with reference to the comparative demographic data provided by the pain-free sample. This is followed by a description of the experience of pain (pain severity, length, site etc) and its influence on activities of daily living (e.g. movement, employment, compensation seeking) for acute, chronic and intermittent pain subgroups separately, and a comparison of these variables made between the subgroups. Last, the influence of pain site on disability and psychological functioning is examined across all respondents with pain. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 103 Comparisons across the Pain Samples: Demographic Data Demographic data are presented to describe each of the samples: pain-free, acute, intermittent and chronic pain (see Table 9). Each of the groups is compared on these demographic data. These comparisons were undertaken to examine whether the acute, intermittent and chronic pain subgroups differed from each other, and also whether they each differed from a pain-free sample recruited using the same methods. Chi-square analyses were used for categorical variables (gender, marital status, and education). Independent group ANOVAs were conducted for the continuous variables (age and adults per household). There were significant differences between the samples on four of the five demographic variables (see Table 9). There were more women in each of the groups, and a greater proportion of female respondents in the pain-free and intermittent samples compared to the acute or chronic samples. The higher proportion of women in the pain-free sample suggests that women are more likely to respond to unsolicited mail questionnaires. Given this likelihood, it is more difficult to determine whether there are more women overall in the community who experience pain. (This will be addressed further in the Discussion). However, it seems likely that intermittent pain is experienced by comparatively more women than men when compared to acute or chronic pain. The relationship status of the pain subgroups varied. Primarily, the intermittent pain sample was more likely to be partnered (and less likely to be divorced) than the other groups. Also, the pain-free sample was less likely to be partnered and a higher proportion of this sample was widowed. The older pain subgroups (intermittent and chronic pain) were the only groups who contained widowed respondents. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 104 The pain subgroups differed on highest level of education completed. In simplest terms, there was a difference between the proportion of each pain group who had completed tertiary education; approximately one-third each of the pain-free and intermittent samples, one-half of the acute sample, and one-fifth of the chronic sample. In contrast, more respondents from the chronic sample had completed Year 10 education only, in comparison with the other groups. The difference in the educational levels may have been related to the difference in the ages between the groups; the two older samples had fewer respondents who had completed tertiary education. This is consistent with Australian census data that indicates older groups are less likely to have completed tertiary education (Australian Bureau of Statistics, 2007). Post-hoc analyses examining age across the three groups indicated that the chronic pain group was older than the acute pain and intermittent pain subgroups. The pain-free sample was also older than the intermittent pain sample. In summary, the overall sample contained more women and was older than expected. While the overall sample contained a higher proportion of female respondents than would be expected based on census estimates (67.1%, cf census estimate of 51% female), the ratio of females reporting chronic pain was consistent with Australian prevalence data for chronic pain (Blyth et al., 2001). Similarly, the median age for the sample was 52.00 years (SD = 16.18), also higher than the projected median age of 44 years for the Queensland adult population (projection for 2006; based on 2001 census data). However, the mean age for female respondents was consistent with previous estimates (Blyth et al., 2001) (M = 51.09, CI = 49.0153.17), although the average age of male participants was higher (M = 58.28, CI = 55.79-60.77). Examination of the pain subgroups revealed there were a number of differences between the acute, intermittent and chronic pain respondents and the Table 9 Demographic Information compared by Pain subgroups Demographic variable Female (%) Statistical comparison ∞ Pain-free N = 348 73.5 a b Acute pain N = 47 59.6 a f Intermittent pain N = 55 79.6 e f Chronic pain N = 320 60.1 b e χ² (3, n = 766) = 18.65, p < .001 66.1 d 76.1 83.3 d e 70.8 e χ² (9, n = 766) = 24.76, p = .003 Relationship status (%) Partnered f ef e Divorced 9.8 15.2 Widowed 11.2 a d 0.0 a 0.0 d 6.0 12.9 8.7 14.8 10.7 6.7 0.0 3.7 9.6 Year 10 23.5 d 19.6 c f 9.3 d e f 33.0 c e Year 12 16.0 15.2 14.8 10.3 Single 1.9 12.6 Highest level of education completed (%) Primary school d 15.2 cf 33.3 df χ² (12, n = 756) = 54.20, p<.001 27.6 c TAFE or equivalent 19.2 Tertiary undergraduate / postgraduate 34.6 b 50.0 c 38.9 e 19.6 b c e 51.15 (17.24) d 47.13 (15.04) c 43.85 (13.72) d e 53.98 (14.95) c e F(3, 759) = 7.83, p <.001 2.03 (.82) 2.32 (1.00) 2.20 (.76) 2.15 (.85) F(3, 749) = 2.48, p = .060 Age in years: Mean (SD) # adults in the household: Mean (SD) ∞ Some N<770 due to missing data on that item a difference between pain-free and acute pain groups b difference between pain-free and chronic pain groups c difference between acute and chronic pain groups d difference between pain-free and intermittent pain e difference between intermittent pain and chronic pain f difference between acute pain and intermittent Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 106 pain-free respondents. Principally, the chronic pain group were older and less likely to have completed tertiary education. The intermittent pain group, which was the youngest group, were more likely to be partnered than the other groups. Description of the Experience of Pain To characterise the nature of pain experienced by the community sample, descriptive analyses were performed for pain characteristics (including severity, onset, previous episodes, and location), treatment seeking behaviour, and the influence of pain on employment, psychological well-being and daily living. These analyses were conducted for the acute, intermittent and chronic pain subgroups separately, and then the subgroups were compared. Pain Variables Participants were asked a number of questions designed to elicit a description of their pain. Items targeted the frequency, site, and severity of their pain experience. Table 10 presents this data. As would be expected because of the way the pain groups were defined, most acute and chronic pain respondents reported daily pain and had pain on the day they completed the questionnaire, whereas only half of the intermittent pain sample experienced pain on the day they completed the questionnaire. Respondents with intermittent or chronic pain were more likely to report that their pain had begun gradually whereas acute pain respondents were more likely to have pain with a sudden onset. The acute and chronic pain respondents were more likely to report that this was their first episode of this type of pain compared to the intermittent sample. Both intermittent and chronic pain participants (approximately one-quarter of each group) were more likely to nominate that they had experienced 21 or more Table 10 Comparison of Pain Variables between Acute, Intermittent and Chronic Pain subgroups Pain variables Pain present today (%) Acute pain (N = 47) Intermittent pain (N = 55) Chronic pain (N = 320) 91.3 52.7 94.3 Site of most severe pain* 10.6 18.2 _ Neck (%) _ 23.6 8.4 Upper back (%) _ _ 8.4 Lower back (%) _ 25.5 26.6 Shoulder/s (%) 17.0 _ _ Hand/s and wrist/s (%) 10.6 _ _ Leg/s (including knee) (%) 21.3 _ 14.4 1.93 (1.45) 1.96 (1.07) 2.81 (1.68) 76.6 NA 65.0 1 month (2-90 days) 4 yrs (2 days-47 yrs) 5 yrs (15 weeks-40 yrs) 36.2 58.2 69.0 # painful sites – Mean (SD) Pain every day Pain duration Median ^ (Range) Gradual onset of pain (%) Previous episodes of pain (%) χ² (2, n = 417) = 79.90, p <.001 χ² (24, n = 360) = 71.77, p <.001 Head (%) a Statistical comparison ∆ F(2, 417) = 11.23, p <.001 χ² (1, n = 367) = 2.47, p = .116∞ _ χ² (2, n = 418) = 19.99, p < .001 χ² (6, n = 307) = 38.34, p <.001 First episode 65.9 25.0 61.4 1-5 previous episodes 25.0 30.0 9.9 6-20 previous episodes 4.5 17.5 4.5 21+ previous episodes 4.5 27.5 24.2 *Three most endorsed sites of most severe pain ∞As intermittent pain by definition did not include daily pain, this subgroup was not included in the chi-square analysis. aAs this was the criterion on which each sample was based this comparison was not conducted ^Data on this variable was positively skewed; therefore median is reported as the measure of central tendency ∆95 chronic pain respondents did not answer this item Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 108 pain episodes when compared to acute pain participants (4.5%). In this sense, the chronic pain participants were divided, with the majority endorsing either that this was their first episode (61%) or that they had experienced 21 or more previous episodes (24%). When examining the location of respondents’ primary pain site, approximately one-quarter of the respondents in the chronic and intermittent samples reported lower back pain. This was different to the acute sample; only 8.5% reported low back pain as their primary pain site. Respondents in the acute sample were more likely to report the leg region as their primary pain site. Chronic pain respondents reported a greater number of pain sites also compared to the acute and intermittent pain subgroups. In terms all sites of significant pain, Figures 5a-c show that more chronic pain participants reported pain in the lower back and legs. A greater number of acute pain participants reported pain in the shoulder, leg, and neck regions. The intermittent pain sample experienced more pain in the neck and shoulder region. Using an arbitrary cut-off of 25%, it can be seen that despite some differences in the most prevalent sites of pain for each pain group, the common sites of pain are the legs, lower back, shoulder, neck and head. Body site Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) feet & ankle/s leg/s hips & pelvis stomach chest lower back upper back hand/s & wrist/s arm/s shoulder/s neck face head 8.5 29.8 8.5 4.3 2.1 19.1 10.6 17 10.6 31.9 25.5 4.3 12.8 0 5 10 15 20 25 30 35 Endorsement frequency (%) of acute pain sample Body site Figure 5a. Percentage of the acute pain subgroup with pain at each body site 3.6 feet & ankle/s leg/s hips & pelvis stomach chest lower back upper back hand/s & wrist/s arm/s shoulder/s neck face head 12.7 1.8 5.5 3.6 32.7 14.5 1.8 7.3 25.5 32.7 5.5 25.5 0 5 10 15 20 25 30 35 Endorsement frequency (%) of intermittent pain sample Figure 5b. Percentage of the intermittent pain subgroup with pain at each body site 109 Body site Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 110 9.1 feet & ankle/s leg/s hips & pelvis stomach chest lower back upper back hand/s & wrist/s arm/s shoulder/s neck face head 32.5 7.2 4.1 4.1 45.3 22.2 8.1 9.1 27.5 26.3 4.1 10.9 0 10 20 30 40 50 Endorsement frequency (%) of chronic pain sample Figure 5c. Percentage of the chronic pain subgroup with pain at each body site Seeking Treatment Over 80% of all the pain subgroups had sought treatment from a health professional for their pain (see Table 11). For all groups, most commonly a general practitioner19 was consulted initially. Physiotherapists and chiropractors were the next most common health professional initially consulted by participants. Respondents with acute pain initially attended a physiotherapist whereas respondents with intermittent or chronic pain were equally likely to see either type of health professional. These figures need to be interpreted cautiously as 25% of chronic pain respondents listed multiple responses, which could not be coded. Two-thirds of those who had sought treatment were still receiving treatment for their pain. Over 70% of the participants had received a diagnosis for their pain; chronic pain respondents were more likely to have received a diagnosis (83.5%), χ² (2, n = 418) = 7.18, p = .028. 19 Another term for general practitioner is primary care physician. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 111 Table 11 Treatment-seeking Variables across the Pain subgroups Pain variables Sought treatment (%) Acute pain (N = 47) Intermittent pain (N = 55) Chronic pain (N = 320) 83.0 86.8 95.0 Practitioner from who treatment was initially sought^ General Practitioner (%) 38.2 53.1 69.2 Physiotherapist (%) 23.5 12.5 7.6 Chiropractor (%) 8.8 15.6 8.5 ^ 79 chronic pain respondents listed multiple responses that were unable to be coded Seventy-eight (24.4%) of the chronic pain sample reported that their pain was due to an arthritis-type condition. Only one respondent from the acute sample and two respondents from the intermittent sample had been diagnosed with arthritis. This difference was statistically significant, χ² (2, n = 417) = 23.10, p <.001. Influence on Employment There were differences between the pain subgroups in terms of the effect that their pain had on their employment. Almost 10% of the chronic pain participants indicated that they were unemployed due to their pain condition whereas only 2% of the acute pain respondents and none of the intermittent pain sample were unemployed as a result of their pain condition. However, 25% of the acute pain participants indicated that their pain had led them to access paid leave, reduced hours or changed duties at work. In contrast, pain had resulted in these kinds of job modifications for a smaller proportion of intermittent (5.45%) and chronic pain participants (8.13%; see Table 12). Of those employed, most reported not missing any work due to pain; 76.2% (n = 21) of the Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 112 acute pain subgroup, 67.7% (n = 34) of the intermittent pain subgroup and 63.7% (n = 124) of the chronic pain subgroup. Table 12 Number of Respondents whose Employment was Affected by their Pain by Pain subgroup Employment status Acute pain Intermittent Chronic pain (N = 47) pain (N = 55) (N = 320) Sick/ workers compensation leave 6 1 4 Reduced hours 2 1 11 Changed duties 1 1 11 Employment affected by pain (Total) 9 3 26 Few respondents intended to seek or were receiving compensation (see Table 13 for frequency data). There were no differences in the ratios of respondents from each subgroup who had sought or intended to seek workers’ compensation payment, χ² (4, n = 251) = 4.42, p = .352, or those who had sought or intended to seek personal injury insurance, χ² (4, n = 414) = 1.28, p = .865. Table 13 Frequency of Compensation Seeking for each Pain subgroup Compensation status Acute pain Intermittent Chronic pain (N = 47) pain (N = 55) (N = 320) Received workers’ compensation 3 1 7 Intend to seek workers’ compensation 1 0 1 Received personal injury insurance 2 2 9 Intend to seek personal injury 0 0 3 insurance Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 113 Psychological Health and Disability Depression and pain-related anxiety scores provided a measure of the psychological health of the pain subgroups. The average depression (CES-D) scores for each of the pain subgroups is provided in Table 14; there were no differences between the three groups, F(2, 404) = 2.92, p = .055. To determine whether the depressive symptoms described by the pain subgroups were meaningful beyond their pain experience20, a cut-off score of 27 was used to identify cases of depression (Geisser et al., 1997). Use of this cut-off score indicated that 17.0% (n = 8) of the acute, 14.5% (n = 8) of the intermittent, and 21.9% (n = 70) of the chronic pain subgroups met the screening test criteria for significant depression. The average pain-related anxiety (PASS) score for the chronic pain subgroup (mean = 33.71; scale range 0-100) was similar to that reported in clinical pain samples (McCracken & Dhingra, 2002). Similar average scores were reported by the acute and intermittent pain subgroups, F(2, 408) = 1.21, p = .301; see Table 14 for this data. A cut-off score of 30 has been previously recommended to indicate high levels of anxiety (Abrams et al., 2007). Re-examining the data in this way revealed that 42.2% (n = 19) of the acute, 49.1% (n = 27) of the intermittent, and 53.1% (n = 165) of the chronic pain subgroups experienced high levels of anxiety. Disability was assessed in two ways. The GCPS provided a classification score taking into account pain intensity and disability, and the RMDQ assessed a number of specific activities of daily living which respondents had difficulty performing due to pain (daily interference). Using the GCPS classifications (see Table 15), approximately one-third each of the acute pain and chronic pain 20 Some of the difficulties in assessing depressive symptoms in pain populations were detailed earlier in the thesis. Recall that depression measures that include somatic symptoms, which could be caused by pain rather than depression, may inflate estimates of depression rates. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 114 Table 14 Average Scores for Psychological Well-being (depression; CES-D and anxiety; PASS) Measures by Pain subgroup Psychological well-being Pain sample Depression (CES-D) Anxiety (PASS) Median IR Median IR Acute pain (n = 47) 13.00 13.00 27.00 26.00 Intermittent pain (n = 55) 11.50 12.00 28.50 29.00 Chronic pain (n = 320) 15.00 17.00 32.00 34.00 Note. Median and IR (interquartile range) is reported because these data were skewed. participants were classified as grade II (low disability – high intensity). In contrast over half of the intermittent group were classified as grade I (low disability – low intensity). Additionally, although respondents from each of the pain subgroups were spread over the four classifications, the chronic pain sample contained a greater proportion of respondents classified as Grade IV (high disability – severely limiting), χ² (6, n = 411) = 32.82, p <.001. Table 15 Graded Chronic Pain Scale Classifications by Pain subgroup Acute pain Intermittent Chronic pain (N = 47) pain (N = 55) (N = 320) Grade Description N % N %^ N %† I low disability-low intensity 13 27.7 30 54.5 66 20.6 II low disability-high intensity 15 31.9 14 25.5 117 36.6 III high disability-moderately limiting 12 25.5 7 12.7 54 16.9 IV high disability-severely limiting 7 14.9 3 5.5 73 22.8 ^ Classifications could not be calculated for 1 respondent † Classifications could not be calculated for 10 respondents In terms of interference with daily living, the RMDQ showed that on average, people with chronic pain reported the highest number of limitations on their Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 115 activities due to their pain (median = 7; IR = 8), followed by the acute pain (median = 5; IR = 8) and then the intermittent pain subgroups (median = 3; IR = 5), F(2, 419) = 373.09, p <.001. The intermittent pain sample reported significantly less activity limitations than either the acute or chronic pain subgroups. The chronic and acute pain subgroups had greater variance in scores compared to the intermittent group also. Table 16 presents the most commonly endorsed activities that pain interfered with for all the pain subgroups. In addition, over one-third of the acute and chronic samples (38.3% and 34.1%, respectively) and one-quarter of the intermittent pain sample reported that they were more irritable due to their pain. Table 16 The Percentage of Respondents who reported that Pain Interfered with these Daily Activities (using the RMDQ) Acute pain Intermittent pain Chronic pain N = 47 (%) N = 55 (%) N = 320 (%) Sleeping 66.0 50.9 57.8 Sitting in one position 55.3 45.5 70.9 Turning over in bed 44.7 32.7 39.4 Dressing 42.6 18.2 4.7 Undertaking heavy jobs around the house 42.6 41.8 50.6 Walking at their usual pace 38.3 27.3 50.6 Using stairs 38.3 10.9 39.7 Putting socks/ stockings on 29.8 12.7 38.4 Bending or kneeling 27.7 27.3 46.6 Activities Coping with and Attitudes towards Pain Strategies for coping with pain have been identified in clinical samples. Standardised measures are available to assess the strategies that are both taught or Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 116 discouraged in treatment programs. It is not clear whether these same coping strategies are used by community samples. As the reliability of the subscales of the coping and attitude measures were low, only subscales with a cronbach’s alpha ≥ .55 were used in the following analyses. Independent group ANOVAs were conducted comparing the acute pain, intermittent pain and chronic pain subgroups on their endorsement of use of coping strategies or strength of attitude (see Table 17). As can be seen, strategies to seek support from others or ask for assistance were used infrequently. The average use of these types of strategies across all pain subgroups was less than 3 days per week. Similarly, participants from all pain subgroups used guarding or resting infrequently to manage their pain, although chronic pain respondents used these two strategies more often than the intermittent pain participants. Relaxation was also used infrequently to manage pain by participants from all pain subgroups. Exercise and/ or stretching were used about half the time. Respondents more frequently persisted with tasks despite pain on approximately 4 days per week. Compared to a clinical sample (Jensen, Turner, & Romano, 2001), the current sample were less likely to seek social support, ask for assistance, guard the painful area, or rest to cope with their pain. Similar levels of endorsement for the task persistence items and higher levels of endorsement particularly by the chronic pain subgroup were seen for relaxation and exercise and/ or stretching subscales compared to the clinical sample. Participants infrequently diverted their attention away from pain by using thinking about pleasant experiences, and were less likely than the clinical sample to use this coping technique (Jensen et al., 2001). Chronic pain respondents were more like to engage in catastrophising than either the acute or intermittent pain respondents; however, catastrophising was still endorsed on average as less than 3 Table 17 Average Endorsement of the Coping Strategies and Attitudes contained in the CPCI, CSQ and SOPA by Pain subgroup compared with the Published Means of a Clinical Sample Subscale Acute pain (N = 47) Intermittent pain (N = 55) Chronic pain (N = 320) F p Clinical sample mean * CPCI seeking social support^ Mean 2.02 SD 2.29 Mean 1.13 SD 1.59 Mean 1.46 SD 1.94 2.68 .070 3.05 CPCI asked for assistance^ 2.52 2.32 1.66 1.78 2.23 2.24 2.13 .120 3.24 CPCI task persistence^ 3.90 2.61 3.84 2.32 4.32 2.39 1.31 .270 4.21 CPCI guarded the area^ 2.32 2.32 1.29 b 1.62 2.68 b 2.26 9.10 .000 4.43 b 1.71 3.03 b 2.34 8.63 .000 4.32 CPCI rested^ 2.70 2.46 1.62 CPCI relaxation^ 2.49 1.93 2.27 2.06 2.77 2.24 1.35 .262 2.40 CPCI exercise/ stretching^ 3.74 2.74 2.85 2.29 3.64 2.33 2.79 .062 3.31 CSQ diverting attention° 1.72 1.88 2.07 1.66 2.34 1.75 2.65 .072 2.79 1.78 12.79 .000 2.47 CSQ catastrophising° 1.62 SOPA expect solicitous responses ˜ a b 1.37 2.42 ab 1.75 1.28 1.35 1.06 1.86 1.28 1.50 1.28 2.45 .088 1.31 SOPA disabled by pain˜ 1.76 1.42 1.20 b 1.05 1.69 b 1.21 3.96 .020 2.48 SOPA link between emotion and pain˜ 1.49 1.24 1.93 1.42 1.91 1.38 1.94 .146 1.96 Note. Higher scores indicate greater use of strategy or stronger beliefs. ^ Maximum range = 0-7 days; halfway point = 3.5 ° Maximum range = 0-6; halfway point = 3.0 ˜ Maximum range = 0-4; halfway point = 2.0 a Difference between the acute and chronic pain subgroups; b Difference between the intermittent and chronic subgroups * Jensen et al. (2001) Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 118 on a 0-6 point scale. This finding was similar to the clinical sample mean (Jensen et al., 2001). On average, respondents across all pain subgroups disagreed with the following beliefs: that their family should act in a solicitous manner towards them, that they were disabled by pain and that there was a link between their emotions and their pain experience. However, compared to intermittent pain participants chronic pain respondents were more likely to agree that they were disabled by pain. Compared to previously published subscale means in a clinical sample (Jensen et al., 2001), this community sample was overall less likely to endorse that they were disabled by pain. Only the acute pain subgroup was less likely to agree that there was a link between their emotions and their pain experience compared to the clinical sample. The mean level of endorsement for the belief that their family should act in a solicitous manner towards them appeared higher in the current intermittent pain and chronic pain participants when compared with a clinical sample mean. The Influence of Pain Site on Functioning As few pain studies use samples with heterogeneous pain sites, the psychological well-being and disability experience of pain respondents was examined grouped by pain site. Table 18 provides the number of respondents with their most severe (primary) pain at each body site as well as functioning data by pain site. As Figure 6 illustrates stomach pain was associated with greater depressive symptoms and neck and shoulder pain fewer depressive symptoms. Pain at other body sites appears to be associated with comparable levels of depressive symptoms. Only the mean depression score for the participants with stomach pain is above the depression cut-off score of 27 (Geisser et al., 1997) indicated in red on Figure 6. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 60.00 Depression (CES-D) 50.00 40.00 30.00 20.00 10.00 0.00 Head Face Neck Shoulder Arm Upper back Lower back Chest Stomach Leg Site of most severe pain Figure 6. Boxplot of depression scores by pain site Hips/ pelvis Hands/ Feet/ wrists ankles including including fingers toes 119 Table 18 Psychological Distress and Disability Data by Primary Pain Site Upper Lower back back 4 32 10 21.5 32 19 5 5 31.6 22.2 GCPS Grade II (%) 36.8 GCPS Grade III (%) GCPS Grade IV (%) Functioning Hip/ Hand/ Feet/ pelvis wrist ankles 58 12 17 16 37 9.5 17 11 13.5 25 50 19 32 25 20 5 3 10.5 7.5 3 4 6 30.0 28.6 57.1 0.0 30.0 36.4 40.0 12.5 25.0 36.7 35.2 14.3 40.0 38.0 45.5 26.7 56.3 11.1 75.0 16.7 22.0 14.3 20.0 12.0 9.1 33.3 18.8 22.2 0.0 16.7 14.3 14.3 40.0 20.0 9.1 0.0 12.5 Head Face Neck Shoulder Arm Chest Stomach Leg N 22 9 42 32 103 7 6 Depression (median) 20 22 13 20 13 13 Anxiety (median) 44 34 13 24 33 Interference (median) 2 4 4.5 6 GCPS Grade I (%) 30.0 33.3 0.0 33.3 42.5 33.3 10.5 33.3 10.0 21.1 11.1 17.5 Note. Depression: Center for Epidemiologic Studies – Depression, Anxiety: Pain Anxiety Symptoms Scale, Interference: Roland Morris Disability Questionnaire, GCPS: Graded Chronic Pain Scales Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 121 Similarly, stomach pain was associated with higher anxiety scores. This can be seen in Figure 7. A red line has been added to the boxplot to indicate where the cut-off score (see Abrams et al., 2007) to designate high levels of anxiety lies. In addition to respondents with stomach pain, respondents with head, face, neck, lower back or pelvis pain are likely to experience high levels of pain-related anxiety. (The average anxiety score for respondents with each of these sites of pain was above the cut-off score). 100.0 Anxiety (PASS) 80.0 60.0 40.0 20.0 0.0 Head Face Neck Shoulder Arm Upper back Lower back Chest Stomach Leg Hips/ pelvis Hands/ Feet/ wrists ankles including including fingers toes Site of most severe pain Figure 7. Boxplot of anxiety scores by pain site Table 18 also provides the median disability score on the RMDQ (interference) for respondents at each pain site, and the percentage of each pain group classified according into the four grades of the GCPS. The two disability measures provide a consistent account of the association between disability and pain Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 122 site, with stomach pain associated with a higher median RMDQ score and high proportion of respondents at Grade IV. For most of the other pain site groups, the highest proportion of participants was classified as Grade II. Discussion This research provides preliminary data on the nature of pain experienced by a community sample. Due to the sampling technique used, designed to achieve a random sample of pain respondents, these results provide an important perspective on pain in the general community that addresses a need for research that extends beyond investigations of chronic pain patients alone. Such a perspective is important to develop and refine transitional process models of pain, and inform treatment and rehabilitation services. Nature of Pain in a Community Sample Chronic pain was reported by 19.6% of participants in this community sample21. Although this estimate must be considered with caution, due to the low response rate in the current study, this estimate is consistent with previous prevalence estimates of chronic pain provided by Blyth et al. (2001; Blyth, March, & Cousins, 2003), who reported a prevalence rate of approximately 20% in a New South Wales sample. The consistency in the chronic pain rate found in this study and the study by Blyth et al. is notable given the methodological differences between the two. In this study, participation was directed primarily towards those experiencing pain; questionnaire items focused on pain. In contrast, the New South Wales study, while focusing on general health only, used a sampling strategy that 21 This estimate accounts for the pain status of all adults who resided in the respondent households. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 123 allowed all householders an equal chance of participating (therefore providing a true test of prevalence). The similarity of these chronic pain frequency estimates provides an independent but confirmatory indication of the prevalence of this condition. Further, whilst the failure to limit selection bias in the current study might be a limitation in measuring prevalence, it also highlights a major strength of the study – this is the first major and detailed survey of the pain experience of a community sample in Queensland. Overall, the findings indicate that chronic pain is a significant health problem in Queensland. Who Experiences Pain? Three subgroups of people with pain were identified – acute pain, intermittent pain and chronic pain – in addition to a pain-free subgroup. The demographic characteristics differed between each of the subgroups. In brief, the chronic pain respondents were mostly female and older than the acute and pain-free respondents. As there were a high percentage of female respondents in the pain-free sample as well as the pain groups, some of the variance in gender may be due to respondent bias; within each household, female members were more likely to respond to the questionnaire. However, the finding of greater proportions of female pain sufferers is consistent with other research (e.g., Blyth et al., 2001; Elliott et al., 1999; Rustøen et al., 2004; Tripp et al., 2006). Similarly, older age has been previously associated with chronic pain (Blyth et al., 2001; Elliott et al., 1999; Ng et al., 2002; Rustøen et al., 2004). Prevalence of chronic pain has also been linked to lower education (Bergman et al., 2001; Rustøen et al., 2004). Consistent with previous research, in this sample, respondents with chronic pain were the least likely to have completed tertiary education. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 124 While it is supposition, one possible explanation for the relative youth of the acute subgroup may be that younger adults engage in activities which are more likely to result in acute injuries such as sporting matches and heavy trades. Consistent with this idea, acute pain respondents were also more likely to report that their pain had a sudden onset. Interestingly, respondents with an intermittent pain condition were more likely to be partnered, compared with the pain-free participants. Some research suggests that a spouse may prolong chronic pain behaviour through secondary reward processes (Jensen et al., 1994), however, this is yet to be demonstrated for other pain conditions like intermittent pain. A Picture of the Pain Experience For those experiencing chronic pain, the lower back was the most common site of pain. Similarly, other literature has reported that the lower back is a frequent site of benign pain (Dionne, 1999; B. F. Walker et al., 2004). Other common painful areas in this sample were the legs, shoulders and neck. These correspond to common sites reported in community samples in Sweden (Bergman et al., 2001; Brattberg, Thorslund, & Wikman, 1989) and North America (Hoffman et al., 2002). While the most common primary pain site for the acute (i.e., shoulder) and intermittent (i.e., neck) pain subgroups differed, there were five common pain sites across all types of pain – legs, lower back, shoulders, neck and head. Chronic pain respondents endorsed a greater number of pain sites on the body compared to acute pain and intermittent pain respondents. This may be due to the pain sensitisation process that is hypothesised to occur once pain becomes chronic (Bement, Skyba, Radhakrishnan, & Sluka, 2003). The pain-free periods that Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 125 the intermittent respondents have may negate this effect, even for those with ongoing pain conditions. In this study, between 15-22% of the respondents with pain were classified as having a depressive illness according to the cut-off scores provided by Geisser et al. (1997). This figure is higher than prevalence estimates for the general Australian population, which range from 4.2-7.4% (Australian Bureau of Statistics, 1997), and highlights the seriousness of the problem of depression for people with pain. In addition, some pain sites appeared to be associated with higher depressive symptoms, particularly stomach pain. However, this figure should be interpreted cautiously as this represented only a small number of participants. For pain-related anxiety symptoms, the average score and distribution in the chronic pain sample was similar to that reported in a university pain clinic sample (M = 38.62, SD = 20.38) (McCracken & Dhingra, 2002). These results indicate that community samples of people with chronic pain, outside a clinical setting, may experience pain-related anxiety symptoms similar to clinical samples and this painrelated anxiety is related to their ability to function22. In addition, the acute pain sample was similarly affected by pain-related anxiety. Two out of five people with pain in the sample would be classified as having high levels of anxiety (Abrams et al., 2007), and head and stomach pain seemed associated with higher levels of anxiety. Disability was related to the level of frequency and duration of pain, with intermittent pain participants reporting the least impairment of daily activities due to pain, and chronic pain respondents, the highest. The acute pain respondents fell between these two groups. Common basic daily activities that were difficult to 22 Bivariate correlations between anxiety (PASS) scores and disability measures (RMDQ and GCPS) revealed significant positive associations. Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 126 complete due to pain, included activities such as sitting in one position, sleeping, undertaking heavy jobs around the house, walking at a usual pace, and bending or kneeling. Again, this highlights the disruptive influence that pain has on the lives of adults. Further, 35% of those with chronic pain were classified as high disability (grade III and IV). These figures are higher than those reported in Canada (Tripp et al., 2006), where only 17% reported high disability, and may be partially explained by the use of a 3-month period to assess activity limitations which can result in a greater portion of respondents being classified at Grades III and IV (Von Korff, 2001). However, a large-scale New South Wales study reported that 27% of their sample was classified as Grades III and IV (Blyth, March, & Cousins, 2003; Blyth, March, Nicholas, & Cousins, 2005). Further examination of disability in an Australian sample is required. As would be expected, the GCPS classifications were much lower for the intermittent pain respondents, and somewhat lower for people with acute pain, compared to the chronic pain respondents. Even though this sample was not recruited from a clinical population, respondents reported their chronic pain had a significant influence on their daily life. Pain was daily for two-thirds of the sample. The pain had led almost all to seek treatment from a healthcare professional, and two-thirds were still receiving treatment for their pain. General practitioners were the most commonly attended healthcare professional as a first source of treatment, highlighting the importance of training for managing long-term pain for general practitioners, especially in light of other research indicating that general practitioners’ fear-avoidance beliefs about remaining active may have a negative influence on chronic pain patients’ recovery (Coudeyre et al., 2006). Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 127 Examination of the types of coping strategies used indicated that, compared to clinical samples, these types of coping strategies were used infrequently. Exploration of the attitudes towards pain that may underlie the use of these strategies showed that respondents did not believe that their family should act in a solicitous manner towards them nor did they believe that they were disabled by pain. This may explain why participants in this study infrequently sought social support or asked for assistance. In addition, if they did not believe they were disabled, this may explain why resting was infrequently used as a coping strategy. It was important to examine the relationships between pain site and psychological distress and physical disability in this research because most research has focused on low back pain only or clinical samples of patients with heterogeneous pain conditions where the influence of pain site has not been examined. As mentioned above, stomach pain was associated with greater depressive symptoms, pain-related anxiety and disability. In addition, higher average pain-related anxiety scores were reported by participants with pain in two general areas of the body; head, face and neck pain, and low back, hip and pelvis pain. In contrast, it appeared that limb pain was less anxiety producing. This may be explained by respondents interpreting pain at the core of the body as more threatening than pain at the extremities. While these results are preliminary, they may indicate that some pain sites should flag clinical attention for the development or expression of pain-related anxiety. Strengths and Limitations of the Baseline Phase The findings reported here need to be interpreted cautiously. The response rate for this study was disappointing. Follow-up of non-respondents was not Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 128 possible because of the recruitment strategy used, which aimed to achieve a random sample of households. Apart from the absence of participation reminders, another reason for the low response rate may be that non-addressed mail was used. While an effort to discriminate the questionnaire from other non-addressed mail was used (e.g., by using official university stationery with the university logo), perhaps the absence of a name and address on the envelope lead to the questionnaire being discarded before it was opened. In addition, since the mail was unaddressed, respondents may have expected that reminders would not be sent and that they could discard the initial questionnaire without recrimination. Other research designed to maximise response rate is encouraged with this population. Compared to census data, it seems likely that there was a respondent bias overall towards older, female respondents, suggesting that these results may not generalise as well to the broader community and are probably most useful to understand the pain experience of women. Whilst future research is needed to replicate our results and test their generalisability, it is important to remember that other research has also reported higher pain prevalence rates for females and older respondents. Other studies also report better response rates from women and older adults (Elliott et al., 1999). Regardless, the strength of this research is that it expands our knowledge of pain in community settings and provides an initial indication of the nature of acute, intermittent and chronic pain in Queensland. In comparison to other Australian community studies (cf Blyth et al., 2005; e.g., Chen et al., 2003; B. F. Walker et al., 2004), this study also targeted wellness behaviour of those with pain including an assessment of the coping strategies that are used. This information can be used in general practice or early intervention programs to target unhelpful beliefs (e.g., that Chapter 4: Phase 1 – Baseline Questionnaires (community sample description) 129 pain is separate to emotional states, which was endorsed by 46.6% of this sample). As stated previously, this study is the first of its kind conducted in Queensland. Chapter Summary This study phase provided information about the demographic and pain characteristics of people who experience acute, intermittent, and chronic pain conditions; data that encompasses the whole spectrum of pain conditions. Longitudinal research to explore further the spectrum of pain conditions is the next step and the follow up data from this group is reported in Chapter 6. Further, through consideration of the characteristics of this non-clinical chronic pain sample, this study may inform and improve the design and delivery of chronic pain assessment and treatment services for people who are yet to present to tertiary referral treatment centres. Given that, as was previously argued, the most costefficient treatment is likely to be delivered to those who will make the transition from acute to chronic pain; the next chapter explores this data using Gatchel’s Model. Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 131 CHAPTER 5: PHASE 1 – BASELINE QUESTIONNAIRES (assessing Gatchel’s Model) Purpose of the Study Recall that the purpose of the baseline phase was twofold. The previous chapter (Chapter 4) reported on the first aim, which was to describe the pain experience of this community sample. This chapter presents the examination of the Phase 1 data in order to meet the second aim for the baseline phase. This aim was to examine Gatchel’s Model using a cross-sectional design. This is an important introductory step as Gatchel’s Model has been exclusively examined using patient samples. This study also provided the baseline measurement of variables believed to be important in the development of chronic pain disability as the first stage of the longitudinal design of this research (see Chapter 6 for the follow-up phase). Brief Introduction Gatchel (1991a) describes a model of the transition from acute pain to chronic pain disability, which was developed in his work with patient samples. However, since chronic pain patients consist of only a small proportion of people with chronic pain, it is valuable to assess the usefulness of Gatchel’s Model in a nonclinical sample. There have been few direct tests of Gatchel’s Model; this study will provide one of the first empirical examinations of the model. This study provides an examination of the key concepts of Gatchel’s Model – physical and mental de-conditioning – using a cross-sectional research design as a preliminary test of this model. The relationships that the proposed risk factors (catastrophising, fear-avoidance beliefs, and the belief that one will not return to Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 132 work) and protective factors (optimism, positive affect, perceived social support, self efficacy, coping and pain beliefs) have with mental and physical de-conditioning will also be examined based on the relationships suggested by Gatchel’s model. Specifically, it was hypothesised that measures of psychological distress (a proxy measure of mental de-conditioning) and self-reported disability (a proxy measure of physical de-conditioning) would be positively correlated. Second, it was hypothesised that pain duration would be positively correlated with psychological distress and self-reported disability, and that respondents with acute pain would report lower psychological distress and disability compared to chronic pain respondents. Third, it was predicted that the risk factor measures would be positively correlated and the protective factor measures would be negatively correlated with the measures of psychological distress and self-reported disability. Fourth, it was hypothesised that the risk and protective factors would account for variance in disability above that accounted for by Gatchel’s variables. Finally, whether pain and psychosocial variables can discriminate the three stages of Gatchel’s Model was assessed. Method Sample The acute pain and chronic pain subgroups only were selected from the sample described in Chapter 4 to examine the elements of Gatchel’s Model. As was reported in Chapter 4, 47 participants had acute pain (pain ≤ 3 months) and 320 participants had chronic pain (pain > 3 months). These two pain subgroups were selected because both experienced constant pain (i.e., pain on more days than not). Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 133 Given that Gatchel’s Model is based upon patient data, this constancy criterion was applied to simulate the severity of pain that might be seen in a clinical sample. Measures The questionnaire included the 12 measures described in Chapter 3 as well as demographic and pain variables. The properties of each standardised measure are presented in Table 19. Recall that these measures were selected to assess the four key areas of study: two aspects were related to Gatchel’s Model (physical and mental de-conditioning) and two represented the possible extensions to the model (risk and protective factors). Pain and disability variables were examined using the Graded Chronic Pain Scales (GCPS) and the Roland and Morris Disability Questionnaire (RMDQ). Mental de-conditioning was examined using the Center for Epidemiologic Studies Depression scale (CES-D) and the Pain Anxiety Symptoms Scale (PASS). Risk and protective factors were assessed using the Fear-Avoidance Beliefs Questionnaire (FABQ), Coping Strategies Questionnaire (CSQ), Chronic Pain Coping Inventory (CPCI), Survey of Pain Attitudes (SOPA), Pain Self efficacy Questionnaire (PSEQ), the positive affect scale of the Affect-Balance Scale, Life Orientation Test – Revised (LOT-R), and the Multidimensional Scale of Perceived Social Support (MSPSS). Table 19 Description of the Measures used in Phase 1 (baseline study) Instrument Graded Chronic Pain Scales (GCPS) Author Von Korff et al., 1990, 1992 Concept measured Roland and Morris Disability Questionnaire (RMDQ) Roland & Morris, 1983a, 1983b Pain-related disability; daily interference (Physical de-conditioning) 24 0-24; higher score reflect greater disability Center for Epidemiologic Studies Depression scale (CES-D) Radloff, 1977 Depressive symptoms (Mental de-conditioning) 20 0-60; higher scores = greater depressive symptoms Cut-off score of 27 for depression in people with pain (Geisser et al., 1997) Pain Anxiety Symptoms Scale-20 (PASS-20) McCracken et al., 1992 Pain-related anxiety (Mental de-conditioning) 20 0-100; higher scores reflect greater anxiety Cut-off score of 30 for high pain-related anxiety (Abrams et al., 2007) Fear-Avoidance Beliefs Questionnaire (FABQ) Waddell et al., 1993 Fear-avoidance beliefs about work & physical activity 16^ Work 0-42; higher scores = stronger fear-avoidance beliefs Physical activity 0-24; higher scores = stronger fear-avoidance beliefs Belief one will not return to work 0-6 10 0-60; higher scores = greater self efficacy Pain Intensity Disability (Physical de-conditioning) # items 7 Item: Belief that they will not return to work Pain Self efficacy Questionnaire (PSEQ) Nicholas, 1989, 2007 Pain-related self efficacy Score range Pain intensity 0-100 Disability estimate 0-100 Four classification levels: I low disability-low intensity; II low disability-high intensity; III high disability-moderately limiting; IV high disabilityseverely limiting Instrument Life Orientation Test – Revised (LOT-R) Affect-Balance Scale – positive affect Author Scheier et al., 1994; Carver & Scheier, 2003 Bradburn, 1969 Concept measured Optimism # items 10 Score range 0-24; higher scores = stronger optimism Positive affect 5 0-5; higher scores = greater positive affect Multidimensional Scale of Perceived Social Support (MSPSS) Zimet et al., 1988 Perceived social support 12 1-7; higher scores = greater perceived social support Coping Strategies Questionnaire (CSQ) short version Rosenstiel & Keefe, 1983 Jensen et al., 2003 Cognitive strategies: Reinterpreting pain sensations; Diverting attention; Ignoring sensations; Praying/ hoping; Coping self-statements; Increased activities; Catastrophising 14 0-6 for each subscale score Chronic Pain Coping Inventory (CPCI) - short version Jensen et al., 1995, 2003 16 0-7 for each subscale score Survey of Pain Attitudes (SOPA) - short version Jensen et al., 1994, 2003 Behavioural strategies: Guarding; Resting; Asking for assistance; Relaxation; Task persistence; Exercise/ stretch; Seeking social support; Coping self-statements Attitudes: Personal control over pain; Appropriateness of solicitous responses ; Appropriateness of pain medications; Inability to function; Relationship between pain & emotion; Medical cure exists for pain problem; Pain signifies harm 14 0-4 for each subscale score ^ Only 11 items are scored Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 136 Statistical Analysis As was reported in Chapter 4, both internal consistency and missing data analyses were conducted with this data. These results are provided below. Internal Consistency Recall that the internal consistency of the GCPS, CES-D, and PASS ranged from .78 (GCPS pain intensity) to .94 (PASS). The internal consistency for the FABQ, PSEQ, MSPSS, LOT-R, and Positive Affect scale are reported in Table 20. Table 20 Internal Consistency for each of the Scales (N = 367) Scale α Fear-Avoidance Beliefs Questionnaire (FABQ) .88 Pain Self efficacy Questionnaire (PSEQ) .93 Life Orientation Test – Revised (LOT-R) .80 Multidimensional Scale of Perceived Social Support (MSPSS) .94 Positive Affect scale of Affect-Balance Scale (AB) .75 As stated in Chapter 4, the internal consistency for subscales of the coping strategy measures (i.e., CSQ, CPCI, and SOPA) were low. Due to the number of and the low reliability estimates for these subscales, a principal components analysis was conducted in order to derive contextually meaningful and reliable measures of underlying coping factors (reported below), which were then used in the analyses in place of the subscales of each of these measures. Missing Data Missing data analysis was reported in Chapter 4. Recall that missing data was replaced using an Estimated Maximisation technique if 70% of the items for a Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 137 scale were available. Missing data replacements were calculated scale by scale. Table 21 displays the number of items and minimum number of items required in each scale for missing data to be replaced. As can be seen in Table 21, less than 3% of the data were imputed on any given scale. This method of missing value replacement was chosen because it prevented relationships between scales being artificially inflated by using data from other scales to estimate missing data. Table 21 Missing Data Imputed Construct Scale # items # item replacements made 9 % possible replacements a 7 Minimum # items required for imputation 5 Disability GCPS Depression CES-D 20 14 67 0.74 Anxiety PASS 20 14 64 0.71 Fear-avoidance beliefs FABQ 12 8 44 0.81 Self efficacy PSEQ 10 7 17 0.38 Optimism LOT-R 6^ 4 11 0.26 Pain attitudes SOPA 14 10 59 0.93 Coping strategies CPCI 16 11 97 1.34 Coping strategies CSQ 14 10 46 0.73 MSPSS 12 8 17 0.31 Social support 2.84 Note. GCPS: Graded Chronic Pain Scales, CES-D: Center for Epidemiologic Studies-Depression, PASS: Pain Anxiety Symptoms Scale, FABQ: Fear-Avoidance Beliefs Questionnaire, PSEQ: Pain Self Efficacy Questionnaire, LOT-R: Life Orientation Test-Revised, SOPA: Survey of Pain Attitudes CPCI: Chronic Pain Coping Inventory, CSQ: Coping Strategies Questionnaire, MSPSS: Multidimensional Scale of Perceived Social Support Missing data was calculated on the total data file (N = 453) a % of possible replacements = (# replacements /N x # items in scale) x 100 ^ While the LOT-R contains 10 items, only 6 items are used to calculate the total score. Filler items were not replaced. Factor Analysis with the Coping and Attitude Subscales As noted earlier, the subscales on the three coping questionnaires (CSQ, CPCI, and SOPA) each consisted of very few items, with low internal consistency. In order to derive reliable measures of the coping strategies captured by these Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 138 questionnaires, the 14 items of the CSQ, 16 items of the CPCI and 14 items of the SOPA were subjected to a principal components analysis. Initial analyses indicated that the items were factorable, KMO = .84. Parallel analysis (O'Connor, 2000) was performed which showed that six factors had an eigenvalue above the 95% confidence interval for eigenvalues, which would have been predicted by chance. A six-factor principal components analysis with varimax rotation yielded a theoretically meaningful and interpretable factor structure, accounting for 44% of the variance in the questionnaire items. These six coping components can be seen in Table 22. After examination of the items that loaded most strongly on each component, the components were labelled Limiting Activities, Use of Distraction, Influence of Emotion, Task Persistence, Catastrophising, and No Expectation for a Cure. Factor scores were derived using the regression method. Results A key aim of the baseline study and the purpose of this chapter was to examine the key concepts of Gatchel’s Model and their predicted relationships. While cross-sectional analyses are limited in their ability to examine processes over time, these analyses provide an important preliminary step as Gatchel’s Model has been exclusively applied to clinical samples. Table 22 Varimax Rotation of the Six Factor Solution for the CSQ, CPCI and SOPA items Scale Item CPCI Limited my standing time Factor 1: Activity limitations .70 Factor 2: Use of distraction CPCI Asked for help with chore .70 CPCI Asked for help carrying, lifting, pushing … .68 CPCI Lay down on a bed .67 CPCI Avoided activity .66 CPCI Talked to friend/ family for support .62 CPCI Rested in chair/ recliner .59 CPCI Got support from friend .58 SOPA Pain does not stop me leading a physically active life -.55 SOPA Pain does not need to interfere with my activity level -.43 CSQ See pain as a challenge & don’t let it bother me .65 CSQ Do something active .62 CSQ Think of things I enjoy doing .60 CSQ Replay pleasant experiences in my mind .59 CSQ Pretend it is not a part of me .59 CSQ Do something I enjoy .54 CSQ Ignore it .52 CSQ Tell myself that I can’t let pain stand in the way .51 CSQ Think of it as some other sensation .48 SOPA I have learned to control pain .45 CSQ Don’t pay any attention to it .41 Factor 3: Influence of emotion Factor 4: Task persistence Factor 5: Catastrophising Factor 6: No cure expectation Scale Item SOPA Stress increases the pain SOPA Connection between emotion & pain level Factor 1: Activity limitations Factor 2: Use of distraction Factor 3: Influence of emotion .72 Factor 4: Task persistence Factor 5: Catastrophising Factor 6: No cure expectation .67 SOPA When I hurt I want my family to treat me better .55 SOPA When I hurt I deserve to be treated with care & concern .54 CSQ I pray for the pain to stop .42 CPCI Don’t let pain interfere with activities .66 CPCI Don’t let pain affect what I do .62 CPCI Exercised to improve physical condition .60 CPCI Told myself that my pain will get better .59 CPCI Stretched the muscles where I hurt .53 CPCI Reminded myself that there are people worse off than I am .49 CPCI Focused on relaxing my muscles .48 SOPA There is little I can do to ease my pain .70 CSQ It’s terrible & never going to get any better .65 CSQ I can’t stand it any more .56 SOPA Pain is a sign that damage is being done .54 SOPA Do not expect a medical cure .61 CSQ Try to think years ahead when I have gotten rid of pain -.55 SOPA Trust that doctors can cure my pain -.53 % of variance explained Cronbach’s alpha^ 14.95 11.61 5.13 4.60 4.24 3.59 .84 .78 .65 .71 .67 .41 Note. Only loading above .4 are displayed. Four items did not load ≥.4 on any component. ^ Cronbach’s alphas was calculated for each factor using the original items that loaded above .4 on that factor. Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 141 The key elements of Gatchel’s Model – pain duration, physical deconditioning and mental de-conditioning (hence referred to as Gatchel’s variables) – were initially examined using correlation analysis to explore the level of relationship between these variables. In addition, the acute pain participants and chronic pain participants were compared on these variables. The inter-correlations between the proposed extension variables and their correlation with Gatchel’s variables were also assessed. This was followed with hierarchal regression analyses, which allowed the unique contribution of each of the independent variables in the prediction of disability to be assessed, and allowed the contribution of the extension variables to be calculated after accounting for Gatchel’s variables. Finally, whether individuals at each of the three stages of Gatchel’s Model could be discriminated using the pain and psychosocial predictors was examined. Prior to the analyses being undertaken, the data were screened for breaches of the assumptions of these statistical analyses. Some breaches of normality were evident. Pain duration was positively skewed (skewness = 1.71, kurtosis = 2.62). The distribution of pain duration was made more normal by applying a square root transformation (skewness = 0.64, kurtosis = -0.34). Analyses were conducted using the original variable and the transformed variable. There was no difference in the results obtained. Therefore, for ease of interpretation, the original variable is reported. Self efficacy (PSEQ) and social support (MSPSS) were also mildly negatively skewed. A square root transformation was applied to these variables. However, this transformation resulted in a positive skew of a similar strength. Therefore, these variables were used unchanged. Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 142 Correlations between Gatchel’s Variables Gatchel’s variables were first examined in relation to each other. To this end, correlation analyses were conducted with the main variables from the model – including pain duration, level of disability, depressive symptoms, and pain-related anxiety (see Table 23). These analyses revealed that pain duration, which is arguably the key factor in the movement between stages of Gatchel’s Model, was not significantly related to any other variable. As can also be seen in Table 23, depression and anxiety scores were highly intercorrelated, and there were moderate positive correlations among the other variables. Table 23 Correlations between Pain Duration and Measures of Gatchel’s key constructs (n = 367)^ Pain duration Pain duration Depression Anxiety Daily interference Pain intensity Global disability 1 Daily Pain Global interfere. intensity disability .040 .018 .074 .054 .707** .488** .454** .565** 1 .521** .480** .579** 1 .467** .598** 1 .587** Depression Anxiety -.001 1 1 Note. Depression: Center for Epidemiologic Studies – Depression, Anxiety: Pain Anxiety Symptoms Scale, Daily interference: Roland Morris Disability Questionnaire, Pain intensity: GCPS Graded Chronic Pain Scales – Intensity estimate, Global disability: GCPS Graded Chronic Pain ScalesDisability estimate ^ The value of n varies due to missing data ** p<.01 Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 143 Assessing Differences between the Acute and Chronic Pain subgroups Independent group t-tests were conducted to examine the differences on the mental and physical de-conditioning variables between respondents early in their pain trajectory (Stage 1: acute pain) with those who had an established pain condition (Stages 2 and 3: chronic pain). These comparisons were conducted to specifically test for differences in pain experience between respondents with acute and chronic pain. Table 24 present the results of these analyses. There were no differences between the acute pain participants and the chronic pain participants on each measure of physical de-conditioning. Neither were there any differences on either measure of mental de-conditioning. Table 24 Comparison of Gatchel’s Variables between Acute and Chronic Pain subgroups Acute pain (N = 47) Measure Mean Chronic pain (N = 320) SD Mean SD Test of significance Mental de-conditioning Depression (CES-D) 16.33 12.31 17.82 12.23 t (350) = -.77, p =.440 Anxiety (PASS) 29.37 18.47 33.73 22.22 t (65.9) = -1.45, p =.151 Daily interference (RMDQ) 6.91 5.65 8.20 5.85 t (365) = -1.29, p =.158 Global disability (GCPS disability estimate) 42.62 26.45 44.14 27.52 t (362) = -1.52, p =.723 Physical de-conditioning Relationships between Gatchel’s Variables and the Proposed Extension Constructs Correlations were conducted between Gatchel’s variables and the proposed extension constructs – fear-avoidance beliefs, belief that one will not return to work, self efficacy, optimism, social support, positive affect and the coping factors (Limiting Activities, Use of Distraction, Influence of Emotion, Task Persistence, Catastrophising, and No Expectation for a Cure) (see Table 25). Due to the large number of analyses conducted, results were interpreted at an alpha level of .01. Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 144 These analyses showed that pain duration was not correlated with the risk and protective factors (r ≤ |.075|), with the exception of weak positive correlations with the belief that one would not return to work (r = .201), Use of Distraction coping factor (r = .149) and the No Expectation for a Cure coping factor (r = .379). All other significant correlations were in the expected direction; the de-conditioning variables were negatively correlated with the protective factors and positively correlated with the risk factors. Primarily, the strongest correlations were between self efficacy and Gatchel’s de-conditioning variables. Self efficacy was negatively correlated with depression, anxiety, daily interference, and global disability (r ≥ .643). Self efficacy was also negatively correlated with the Limiting Activities coping factor (r = -.617). In addition, the Limiting Activities coping factor was strongly positively correlated with one of the physical de-conditioning measures, daily interference (RMDQ); r = .655. Predicting De-conditioning: Regression Analyses Hierarchical regression analyses were conducted to examine the relative contribution of each of the predictor variables from Gatchel’s Model, and the risk and protective factors on each measure of de-conditioning. Assumption testing revealed that there were no assumption breaches. Parallel analyses were conducted for the two disability measures (daily interference; RMDQ, and global disability; GCPS disability estimate) and two mental de-conditioning measures (depressive symptoms; CES-D, and anxiety; PASS). Gatchel’s variables were entered into the regression as the first step. As the second step, the risk and protective factors were grouped in the following way: personality characteristics (i.e., optimism and positive affect) were entered together, social support was entered alone, pain beliefs (i.e., self Table 25 Correlations between Measures of Gatchel’s key constructs and the Extension Variables (n = 367)^ Catastrophising Will not return Fear-avoidance .379** 1 .707** .488** .454** .565** -.643** -.512** -.352** -.411** .398** .354** .381** -.114 .471** -.194** .328** .035 1 .521** .480** .579** -.680** -.433** -.173* -.304** .562** .432** .449** -.208** .462** -.075 .417** -.035 1 .467** .598** -.667** -.248** -.074 -.213** .534** .527** .655** -.057 .135 -.079 .242** .054 1 .587** -.481** -.304** -.005 -.191** .361** .333** .370** -.051 .155* -.062 .360** .016 1 -.669** -.253** -.032 -.219** .525** .462** .572** -.115 .184* -.113 .235** .032 1 .372** .106 .386** -.543** -.567** -.617** .251** -.262** -.210** -.313** -.087 1 .336** .490** -.283** -.160* -.123 .147* -.231** .221** -.384** -.096 1 .380** -.081 .009 .130 .086 -.163* .158* -.117 -.118 1 -.166* -.111 -.099 .288** -.090 .220** -.261** -.073 1 .583** .533** -.081 .129 -.074 .297** .096 1 .537** .039 .162* -.094 .188* .246** 1 -.016 .035 -.056 -.044 .004 1 .044 .049 -.064 .018 Use of No Cure .042 Expectation .046 Task .060 persistence .149* Influence of .057 Emotion .201** Distraction .045 Limiting -.017 Activity .056 to work Use of Distraction -.075 beliefs Limiting Activities Positive affect Will not return to work Social support Fear-avoidance beliefs Optimism Positive affect Self efficacy Social support -.050 Global Optimism .054 disability Self efficacy .074 Pain Global disability .018 intensity Pain intensity .040 Daily Daily interference -.001 interference Anxiety Anxiety Depression Depression Pain duration .008 .016 1 -.006 -.014 1 .020 Note. Depression: Center for Epidemiologic Studies – Depression, Anxiety: Pain Anxiety Symptoms Scale, Daily interference: Roland Morris Disability Questionnaire, Pain intensity: GCPS Graded Chronic Pain Scales – Intensity estimate, Global disability: GCPS Graded Chronic Pain Scales – Disability estimate, Self efficacy: Pain Self Efficacy Questionnaire, Optimism: Life Orientation Test – Revised, Social support: Multidimensional Scale of Perceived Social Support, positive affect: Affect-Balance Coping factors: Limiting Activities, Use of Distraction, Influence of Emotion, Task persistence, Catastrophising, No Expectation for a Cure ^ The value of n varies due to missing data * p<.01 ** p<.001 No Cure -.013 Catastrophising Scale, Fear-avoidance beliefs: Fear-Avoidance Beliefs Questionnaire, Not return to work: single item Expectation Catastrophising Task persistence 1 Influence of Emotion Task persistence Use of Distraction Limiting Activity Will not return to work Fear-avoidance beliefs Positive affect Social support Optimism Self efficacy Global disability Pain intensity Daily interference Anxiety Depression Influence of Emotion Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 147 efficacy and the fear-avoidance beliefs) were entered together, and the coping factors were entered together. Separate hierarchical regression analyses were conducted for each group of risk and protective factors; these series of separate second regression steps are referred to as steps 2A, 2B, 2C and 2D. The third step contained all of the predictor variables. Due to the high intercorrelations amongst the predictor variables, the predictor variables were entered in this way to separate out the influence of each predictor type on disability. Daily Interference: RMDQ scores As can be seen in Table 26, mental de-conditioning variables explained approximately 30% of the variance in the RMDQ scores, F(3, 306) = 44.26, p <.001. Both depression and anxiety scores were significant predictors of RMDQ scores, uniquely explaining approximately 3% and 7% of the variance in the RMDQ scores, respectively. Pain duration was not a significant predictor of daily interference. When examining the different combinations of the second step of predictors, it can be seen that the personality characteristics (optimism and positive affect)23 and social support24 were not significant predictors; depression and anxiety scores remained significant predictors in Steps 2A and 2B. When beliefs about pain were entered as the second step, all beliefs (self efficacy, fear-avoidance beliefs, and the belief that one will not return to work) were significant predictors. As a group they explained approximately 21% of additional variance above that explained by the mental de-conditioning variables, F(3, 292) = 42.90, p <.001. The entry of the coping factors as the second step revealed that, as a group, the coping variables explained approximately 24% of additional variance beyond that explained by the 23 24 F(2, 293) = 1.54, p =.216 F(1, 300) = 2.99, p =.085 Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 148 Table 26 Hierarchical Regression Analyses to Predict Disability using the RMDQ Step Predictor variable B SE β sr² R² R² change DV: Daily Interference (RMDQ) 1 Pain duration .011 .032 .017 _ .303 _ Depression (CES-D) .114 .033 .233* .027 Anxiety (PASS) .099 .018 .360** .065 2A Pain duration .020 .033 .030 _ .311 .007 Depression (CES-D) .128 .036 .262** .030 Anxiety (PASS) .104 .019 .379** .071 Optimism (LOT-R) .124 .071 .110 _ Positive affect (AB) -.180 .219 -.047 _ 2B Pain duration .009 .032 .013 _ .307 .004 Depression (CES-D) .133 .035 .272** .033 Anxiety (PASS) .094 .019 .343** .058 _ Social support (MSPSS) .363 .210 .089 _ 2C Pain duration -.020 .029 -.029 .514 .211** _ Depression (CES-D) .030 .030 .062 _ Anxiety (PASS) .002 .019 .008 Self efficacy (PSEQ) -.182 .028 -.430** .072 Fear-avoidance beliefs (FABQ) .069 .020 .200** .021 Belief that one will not return to work .356 .130 .151* .013 _ 2D Pain duration -.022 .029 -.032 .547 .244** _ Depression (CES-D) .074 .029 .150 _ Anxiety (PASS) .030 .020 .108 Limiting Activities 3.226 .292 .566** .190 _ Use of Distraction .104 .253 .017 _ Influence of Emotion .015 .321 .002 _ Task persistence -.046 .242 -.008 Catastrophising .919 .300 .154* .015 _ No Expectation for a Cure -.022 .254 .075 _ 3 Pain duration -.017 .030 -.025 .597 .294** _ Depression (CES-D) .042 .033 .087 _ Anxiety (PASS) .004 .021 .014 _ Optimism (LOT-R) .086 .060 .075 _ Positive affect (AB) .055 .187 .014 _ Social support (MSPSS) -.320 .187 -.079 Self efficacy (PSEQ) -.134 .032 -.315** .027 _ Fear-avoidance beliefs (FABQ) .031 .020 .090 _ Belief that one will not return to work .161 .135 .068 Limiting Activities 2.163 .378 .380** .050 _ Use of Distraction .222 .269 .037 _ Influence of Emotion -.154 .319 -.026 _ Task persistence .251 .245 .043 _ Catastrophising .488 .321 .083 _ No Expectation for a Cure .049 .268 .008 Note. Unique variance (sr²) was calculated only for significant predictors * p<.01 ** p<.001 Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 149 mental de-conditioning variables, F(6, 291) = 25.33, p <.001. However, only the Limiting Activities and Catastrophising coping factors were significant predictors of RMDQ scores, uniquely explaining 19% and 1.5% of the variance in RMDQ scores, respectively. Both depression and anxiety scores were superseded by the entry of the pain belief variables and the coping factors and were no longer significant predictors in Steps 2C and 2D. At Step 3, when all of the predictor variables were entered into the model, the only two significant predictors were self efficacy and the Limiting Activities factor, which accounted for approximately 3% and 5% of variance in RMDQ scores, respectively. At Step 3, approximately 60% of the variance in RMDQ scores was accounted for; this was an additional 29% beyond mental de-conditioning. Global Disability: GCPS disability estimate The same procedure was repeated for the GCPS disability estimate, with the predictors grouped together and entered into the model separately at the second step. Therefore Step 1 contained the mental de-conditioning variables and pain duration, Step 2 contained the risk and protective factors grouped as in the previous analysis and Step 3 contained all the predictor variables. Mental de-conditioning variables explained approximately 36%; both depression and anxiety scores were significant predictors (see Table 27). The addition of optimism and positive affect did not improve the predictive power of the model beyond Gatchel’s variables, F(2, 292) = 3.06, p = .049. However, each of the other second step combinations (social support, pain beliefs, and coping factors) each explained additional variance above that explained by Gatchel’s variables. In combination with Gatchel’s variables, social support explained an additional 2% Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 150 Table 27 Hierarchical Regression Analyses to Predict Disability using the GCPS disability estimate Step Predictor variable B SE β sr² R² DV: Global disability (GCPS disability estimate) 1 Pain duration .144 .142 .046 _ .366 Depression (CES-D) .686 .146 .302** .046 Anxiety (PASS) .444 .082 .350** .062 2A Pain duration .189 .146 .061 _ .371 Depression (CES-D) .769 .160 .338** .050 Anxiety (PASS) .478 .084 .378** .070 Optimism .771 .314 .148 _ Positive affect -.678 .980 -.038 _ 2B Pain duration .125 .141 .040 _ .390 Depression (CES-D) .865 .153 .382** .066 Anxiety (PASS) .400 .081 .316** .049 Social support 3.351 .912 .178** .028 2C Pain duration .066 .132 .021 _ .518 Depression (CES-D) .333 .137 .149 _ Anxiety (PASS) .055 .085 .044 _ Self efficacy -.819 .126 -.421** .069 Fear-avoidance beliefs .293 .089 .185* .018 Beliefs that one will not return to work .566 .594 .052 _ 2D Pain duration .088 .145 .028 _ .486 Depression (CES-D) .587 .145 .260** .029 Anxiety (PASS) .176 .099 .139 _ Limiting Activities 10.630 1.439 .404** .097 Use of Distraction -.527 1.253 -.019 _ Influence of Emotion -.511 1.579 -.018 _ _ Task persistence -1.083 1.190 -.040 _ Catastrophising 3.286 1.475 .120 _ No Expectation for a Cure .711 1.257 .026 _ 3 Pain duration .177 .143 .056 .558 Depression (CES-D) .576 .158 .259** .022 _ Anxiety (PASS) .040 .099 .032 _ Optimism .693 .288 .134 _ Positive affect .322 .893 .018 _ Social support .863 .891 .047 Self efficacy -.793 .150 -.410** .046 _ Fear-avoidance beliefs .245 .096 .154 _ Beliefs that one will not return to work .002 .645 .000 _ Limiting Activities 3.060 1.801 .118 _ Use of Distraction .387 1.284 .014 _ Influence of Emotion -1.739 1.522 -.064 _ Task persistence -.076 1.166 -.003 _ Catastrophising 1.043 1.532 .039 _ No Expectation for a Cure -.880 1.279 -.032 Note. Unique variance (sr²) was calculated only for significant predictors * p<.01 ** p<.001 R² change _ .005 .024** .152** .120** .192** Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 151 compared to Gatchel’s variables alone, F(1, 300) = 13.49, p <.001. Self efficacy, fear-avoidance beliefs and the belief that one would not return to work accounted for an additional 15% on top of Gatchel’s variables, F(3, 292) = 30.86, p <.001. Self efficacy and fear-avoidance beliefs were significant predictors, uniquely explaining approximately 7% and 2% of the variance in the GCPS disability estimate, respectively. The coping factors explained an additional 12% beyond Gatchel’s variables, F(6, 290) = 11.66, p <.001. Of the coping factors, Limiting Activities was the strongest and only significant predictor, explaining approximately 5% of unique variance in the GCPS disability estimate. When all predictors were entered into the model, approximately 56% of the variance in the GCPS disability estimate was accounted for; this was an additional 19% beyond Gatchel’s variables. The strongest unique predictors were depression (accounting for approximately 2% of the variance) and self efficacy (which accounted for approximately 5% of the variance). Depression: CES-D scores A similar procedure was repeated for depression scores, with the predictors grouped together and entered into the model separately at the second step. Therefore Step 1 contained the physical de-conditioning variables and pain duration, Step 2 contained the risk and protective factors grouped as in the previous analysis and Step 3 contained all the predictor variables. Physical de-conditioning variables explained approximately 34%; both disability scores were significant predictors (see Table 28). Each of the other second step combinations (personality characteristics, social support, pain beliefs, and coping factors) each explained additional variance above that explained by Gatchel’s variables. The addition of optimism and positive affect improved the predictive Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 152 power of the model beyond Gatchel’s variables, F(2, 298) = 51.02, p <.001. Both optimism and positive affect were significant predictors, uniquely explaining approximately 8% and 2% of the variance in depression scores, respectively. In combination with Gatchel’s variables, social support explained an additional 9% compared to Gatchel’s variables alone, F(1, 307) = 59.04, p <.001. Similarly, self efficacy, fear-avoidance beliefs and the belief that one would not return to work accounted for an additional 9% on top of Gatchel’s variables, F(3, 293) = 19.42, p <.001. Self efficacy was a significant predictor, uniquely explaining approximately 10% of the variance in depression scores. The coping factors explained an additional 20% beyond Gatchel’s variables, F(6, 292) = 23.35, p <.001. Of the coping factors, Influence of Emotion, Task Persistence and Catastrophising were significant predictors, explaining approximately 16%, 2% and 5% of unique variance in depression. When all predictors were entered into the model, approximately 67% of the variance in depression was accounted for; this was an additional 32% beyond Gatchel’s variables. The strongest unique predictors were global disability, optimism, social support, self efficacy, Influence of Emotion and Catastrophising. Anxiety: PASS scores This procedure was repeated with the anxiety scores as the dependent variable. Therefore, Step 1 contained the physical de-conditioning variables and pain duration, Step 2 contained the risk and protective factors grouped as in the previous analysis and Step 3 contained all the predictor variables. Physical de-conditioning variables explained approximately 38%; both disability scores were significant predictors (see Table 29), explaining Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 153 approximately 6% and 10% of the variance, respectively. Each of the other second step combinations (individual characteristics, social support, pain beliefs, and coping factors) each explained additional variance above that explained by Gatchel’s variables. The addition of optimism and positive affect improved the predictive power of the model beyond Gatchel’s variables, F(2, 297) = 25.74, p <.001. Optimism was the only significant predictor, uniquely explaining approximately 7% of the variance in anxiety scores. In combination with Gatchel’s variables, social support explained an additional 2% compared to Gatchel’s variables alone, F(1, 305) = 9.56, p =.002. Self efficacy, fear-avoidance beliefs and the belief that one would not return to work accounted for an additional 16% on top of Gatchel’s variables, F(3, 297) = 34.40, p <.001. Self efficacy and fear-avoidance beliefs were significant predictors, uniquely explaining approximately 9% and 4% of the variance in the anxiety scores, respectively. The coping factors explained an additional 30% beyond Gatchel’s variables, F(6, 295) = 47.22, p <.001. Of the coping factors, Limiting Activities, Use of Distraction, Influence of Emotion and Catastrophising were significant predictors, explaining approximately 4%, 3%, 18% and 12% of unique variance in anxiety, respectively. When all predictors were entered into the model, approximately 72% of the variance in anxiety scores was accounted for; this was an additional 34% beyond Gatchel’s variables. The strongest unique predictors were self efficacy, fearavoidance beliefs, Limiting Activities, Use of Distraction, Influence of Emotion, Catastrophising and No Expectation for a Cure. Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 154 Table 28 Hierarchical Regression Analyses to Predict Depression scores (CES-D) Step Predictor variable B SE β sr² R² R² change DV: Depression (CES-D) 1 Pain duration -.039 .062 -.028 _ .344 _ Daily interference (RMDQ) .500 .116 .245** .039 Global disability (GCPS disability) .180 .025 .407** .106 2A Pain duration -.078 .056 -.057 _ .503 .159** Daily interference (RMDQ) .378 .104 .185** .022 Global disability (GCPS disability) .145 .023 .329** .069 Optimism (LOT-R) -.780 .110 -.340** .084 Positive affect (AB) -1.102 .370 -.142* .015 2B Pain duration -.006 .058 -.005 _ .438 .094** Daily interference (RMDQ) .446 .108 .218** .031 Global disability (GCPS disability) .186 .023 .421** .114 .107 Social support (MSPSS) -2.743 .357 -.328** _ 2C Pain duration -.027 .063 -.019 .436 .092** _ Daily interference (RMDQ) .082 .129 .040 .016 Global disability (GCPS disability) .081 .028 .182* Self efficacy (PSEQ) -.441 .060 -.508** .101 Fear-avoidance beliefs (FABQ) .050 .042 .071 _ Belief that one will not return to work -.429 .285 -.089 _ _ 2D Pain duration -.076 .059 -.055 .543 .199** _ Daily interference (RMDQ) .254 .120 .124 .290 Global disability (GCPS disability) .103 .024 .233** Limiting Activities 1.664 .682 .142 _ _ Use of Distraction -.949 .493 -.077 .159 Influence of Emotion 5.089 .497 .413** .015 Task persistence -1.521 .482 -.125* Catastrophising 3.029 .525 .249** .051 _ No Expectation for a Cure .321 .511 .027 _ 3 Pain duration -.046 .056 -.032 .666 .322** _ Daily interference (RMDQ) .111 .114 .054 .018 Global disability (GCPS disability) .088 .023 .196** .020 Optimism (LOT-R) -.436 .110 -.188** _ Positive affect (AB) -.509 .345 -.065 .026 Social support (MSPSS) -1.527 .338 -.184** Self efficacy (PSEQ) -.173 .062 -.199* .010 _ Fear-avoidance beliefs (FABQ) -.035 .037 -.049 _ Belief that one will not return to work -.077 .252 -.016 Limiting Activities 1.436 .727 .123 _ _ Use of Distraction .106 .491 .009 .067 Influence of Emotion 3.608 .500 .293** _ Task persistence -.422 .455 -.035 .013 Catastrophising 1.770 .557 .147* _ No Expectation for a Cure -.393 .491 -.032 Note. Unique variance (sr²) was calculated only for significant predictors * p<.01 ** p<.001 Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 155 Table 29 Hierarchical Regression Analyses to Predict Anxiety scores (PASS) Step 1 2A 2B 2C 2D Predictor variable DV: Anxiety (PASS) Pain duration Daily interference (RMDQ) Global disability (GCPS disability) Pain duration Daily interference (RMDQ) Global disability (GCPS disability) Optimism (LOT-R) Positive affect (AB) Pain duration Daily interference (RMDQ) Global disability (GCPS disability) Social support (MSPSS) Pain duration Daily interference (RMDQ) Global disability (GCPS disability) Self efficacy (PSEQ) Fear-avoidance beliefs (FABQ) Belief that one will not return to work Pain duration SE β sr² R² R² change _ .056 .098 _ .040 .071 .073 _ _ .051 .100 .019 _ _ _ .376 _ .463 .087** .391 .015* .538 .162** .681 .305** .717 .341** .011 1.072 .380 -.053 .923 .265 -1.298 .010 .035 1.026 .312 -2.041 .063 .064 .086 -.750 .359 -.657 .061 .324 .110 .204 .044 .106 .195 .042 .204 .690 .111 .204 .044 .660 .102 .210 .045 .097 .068 .463 .089 .180 .004 .294** .390** -.021 .253** .335** -.317** .001 .014 .281** .394** -.139* .025 .018 .108 -.486** .285** -.077 .025 .089 .092 .043 _ _ _ .101 .036 .128* .009 6.513 -3.872 1.024 .739 .314** -.176** .044 .030 Influence of Emotion 9.463 .744 .433** .175 Task persistence -.759 .721 -.035 Catastrophising 8.150 -1.828 .786 .767 .379** .129 .050 .042 -.424 .621 -.852 -.320 .201 -.075 4.077 -2.704 .091 .186 .038 .174 .561 .542 .099 .060 .409 1.183 .799 .051 .014 .052 -.103 .045 -.059 -.207* .158* -.009 .196* Daily interference (RMDQ) Global disability (GCPS disability) Limiting Activities Use of Distraction No Expectation for a Cure 3 B Pain duration Daily interference (RMDQ) Global disability (GCPS disability) Optimism (LOT-R) Positive affect (AB) Social support (MSPSS) Self efficacy (PSEQ) Fear-avoidance beliefs (FABQ) Belief that one will not return to work Limiting Activities Use of Distraction -.085 -.124* _ .116 _ _ _ _ _ _ _ .011 .012 _ .012 .012 .087 Influence of Emotion 7.424 .812 .339** _ Task persistence .248 .742 .012 .043 Catastrophising 5.850 .904 .274** .012 No Expectation for a Cure -2.708 .792 -.125* Note. Unique variance (sr²) was calculated only for significant predictors * p<.01 ** p<.001 Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 156 Table 30 The Final Betas for the Predictors of the Physical and Mental De-conditioning Measures Physical de-conditioning Daily Global interference disability Mental de-conditioning Depression Anxiety Pain duration -.025 .056 -.032 .051 Daily interference (RMDQ) .087 .259** .054 .014 Global disability (GCPS disability) .014 .032 .196** .052 Optimism (LOT-R) .075 .134 -.188** -.103 Positive affect (AB) .014 .018 -.065 .045 Social support (MSPSS) -.079 .047 -.184** -.059 Self efficacy (PSEQ) -.315** -.410** -.199* -.207* Fear-avoidance beliefs (FABQ) .090 .154 -.049 .158* Belief that one will not return to work .068 .000 -.016 -.009 Limiting Activities .380** .118 .123 .196* Use of Distraction .037 .014 .009 -.124* Influence of Emotion -.026 -.064 .293** .339** Task persistence .043 -.003 -.035 .012 Catastrophising .083 .039 .147* .274** No Expectation for a Cure .008 -.032 -.032 Note. The β weights presented are those at the last step of the regression analysis. -.125* * p<.01 ** p<.001 Results of the Hierarchical Regressions combined Table 30 presents the final beta weights for the each of the hierarchical regressions conducted to examine the predictive ability of Gatchel’s variables and the risk and protective variables to explain the physical and mental de-conditioning variables. As can be seen in Table 30, self-efficacy is a consistent predictor of deconditioning variance. Also, many more variables accounted for unique variance in the measures of mental de-conditioning than physical de-conditioning. Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 157 Comparing the 3 Stages of Gatchel’s Model A final examination of Gatchel’s Model explored whether the three stages of Gatchel’s Model could be discriminated on the basis of the psychosocial factors known to be affected by pain (without reliance on pain duration). This was done by classifying the respondents into the three stages of Gatchel’s Model on the basis of disability, examining the univariate relationships between each predictor variable and Gatchel’s stages and then conducting a discriminant function analysis. Respondents were classified into the three stages of Gatchel’s Model in the following way. As stage 3 is the end stage of disability and is associated with a total focus on the pain experience and lack of outside interests and activities, respondents with chronic pain who were unemployed because of their pain condition and had grade III or IV pain severity (according to the GCPS) were categorised as Stage 3 (n = 21). Stage 2 is the middle stage where pain has had a lesser influence on lifestyle but pain has been ongoing. Therefore respondents with ongoing pain who did not meet the criteria for Stage 3 were classified as being in Stage 2 (n = 197). Stage 1 is the acute phase; acute pain respondents were classified as Stage 1 (n = 47). Because these analyses were exploratory and because of the large number of possible predictor variables, independent group ANOVAs were conducted as a second step. These analyses examined the univariate relationships between each predictor variable and Gatchel’s stages (see Table 31)25. On the basis of these results, a direct discriminant function analysis was performed using 12 variables (which significantly differed at the univariate level) as predictors of membership in three groups. Predictors were Gatchel’s variables (depression, anxiety and daily interference), pain variables (number of pain sites) and risk and protective factors 25 Because the GCPS grades were used to classify respondents into Gatchel’s stages, the GCPS pain intensity estimates and disability estimate were not included as predictor variables. Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 158 (fear-avoidance beliefs, optimism, self efficacy and the coping factor scores – Limiting Activities, Use of Distraction, Influence of Emotion, Catastrophising and No Expectation of Cure). The data met the assumptions required for this multivariate technique. Two discriminant functions were calculated, with a significant overall Wilks Lambda, Λ = .574, χ² (24, n = 237) = 126.79, p<.001, indicating that overall the predictors could discriminate between the three groups. After removal of the first function, the residual Wilks Lambda was significant, Λ = .815, χ² (11, n = 237) = 46.74, p<.001, indicating that there was still a strong correlation between groups and predictors in the second function was not explained by the first function. The first function accounted for 29.6% and the second function 18.5 % of the variability. The functions were labelled by examining the structure matrix. The first function was labelled Catastrophising and the second function, Managing Pain. The discriminant function scores are plotted against in the two functions can be seen in Figure 8. Univariate ANOVAs followed by Tukey post-hoc tests conducted with each function revealed that the first function separated all three stages from each other. The second function also separated all three stages from each other. The post-hoc tests revealed and as is demonstrated in Figure 8, Stage 3 respondents reported greater catastrophising, fewer expectations for a cure and greater number of pain sites compared to both Stage 1 and 2 respondents. Stage 2 participants also reported greater catastrophising, fewer expectations for a cure and greater number of pain sites in comparison to Stage 1 respondents. Compared to Stage 1 and 3 participants, Stage 2 participants reported greater optimism, and less disability, Table 31 Analysis of Differences between the Stages identified in Gatchel’s Transitional Model of Pain Measures Possible Stage 1 (N = 47) Stage 2 (N = 197) Stage 3 (N = 21) F p 11.68 14.68 <.001 21.40 15.59 <.001 5.21 18.61 <.001 score range Mean SD Mean SD Mean SD 0-60 16.33 a 12.31 18.54 b 11.93 32.90 a b 18.47 b 21.42 59.70 ab 5.28 15.10 ab Gatchel’s variables Depression Anxiety 0-100 29.37 a a 34.42 b 5.65 8.10 1.93 a c 1.45 2.92 b c 1.60 4.24 a b 2.45 14.58 <.001 0-66 29.50 a 15.44 32.50 b 15.82 53.55 a b 10.53 18.90 <.001 Optimism (LOT-R) 0-24 16.17 a 5.25 5.03 .007 Positive affect (AB) 0-5 3.33 Social support (MSPSS) 1-7 5.61 Daily interference 0-24 6.91 _ Pain variables # sites Risk & Protective factors Fear-avoidance beliefs (FABQ) Self efficacy (PSEQ) Limiting Activities Use of Distraction 0-60 44.35 _ 0.24 a _ c Influence of Emotion _ Task Persistence _ Catastrophising No Expectations for Cure a a _ _ -0.41 -0.31 ac 0.11 -0.55 ac -0.71 ac 5.28 14.87 1.52 3.13 1.28 5.29 14.30 42.35 1.18 1.02 b b ab 5.07 11.90 1.56 2.67 1.74 1.29 .278 1.55 4.96 1.68 1.50 .224 12.29 20.54 <.001 ab 12.84 23.45 0.05 b 0.93 1.29 a b 0.71 14.48 <.001 0.15 c 0.95 -0.22 0.73 6.69 .001 0.85 0.02 c 1.02 0.38 a 1.01 3.65 .027 1.14 0.03 0.98 0.21 0.86 0.92 0.27 0.07 c bc 0.95 0.99 difference between Stage 1 and 3 b difference between Stage 2 and 3 c difference between Stage 1 and 2 0.79 0.37 .691 a 1.09 16.64 <.001 ab 0.86 15.49 <.001 0.56 0.54 Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 160 depression and anxiety. Stage 1 participants also reported greater optimism, and less disability, depression and anxiety in comparison to Stage 3 participants. Gatchel's stages 4 Optimism Stage1 Stage 2 Stage 3 Group Centroid 2 Function 2 Stage 2 Stage1 0 Stage 3 -2 Limited activities Daily interference Fear-avoid beliefs -4 -6 -3 -2 -1 0 1 Function 1 2 3 Catastrophising No expectation for cure # pain sites Figure 8. Scatter plot of the discriminant function scores The classification scheme, using a sample proportions as prior probabilities, classified 79.3% of the participants correctly (see Table 32). Respondents in Stage 2 were the most correctly classified (92% correct), followed by Stage 1 (43%). To assess the accuracy of the group predictions, the kappa coefficient was computed to assess how well the discriminant function improved prediction above chance level. This statistic was significant with a moderate value of .411 (p<.001). The stability of the classification procedure was determined using cross-validation of the classification functions. Using the leave-one-out technique, 75.5% of the cases were Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 161 correctly classified. However, the misclassification of the Stage 3 respondents increased from 64.7% to 88.2%, indicating that the classification scheme was affected by the small cell sizes and is likely to be sample specific. Table 32 Results (%) of the Classification Scheme Original Cross-validated Gatchel’s Stages Predicted Group Membership Stage 1 Stage 2 Stage 3 Stage 1 42.9% 54.8% 2.4% Stage 2 5.1% 92.1% 2.8% Stage 3 5.9% 58.8% 35.3% Stage 1 35.7% 61.9% 2.4% Stage 2 5.6% 91.0% 3.4% Stage 3 5.9% 82.4% 11.8% Discussion This research provides preliminary cross-sectional data on the key concepts from Gatchel’s Model in a non-clinical sample. A key aim of this study was to investigate the transitional model of pain proposed by Gatchel (1991a), which suggests that disability and psychological distress will increase as pain becomes chronic, and continue to worsen as pain becomes more severe. Contrary to the predictions based on this model, pain duration was not associated with psychological distress (a proxy measure of mental de-conditioning) or self-reported disability (a proxy measure of physical de-conditioning). Gatchel suggests that mental and physical de-conditioning influence and interact with each other. While depression and anxiety scores did significantly correlate with disability measures, in combination they only accounted for about one-third of the variance in disability. Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 162 While the relationship between pain duration and de-conditioning was not so clear cut, it was expected that there would be differences between the acute and chronic pain subgroups on levels of mental and physical de-conditioning. Also contrary to this prediction, there were no differences between the pain groups on depressive symptoms or pain-related anxiety (i.e., mental de-conditioning) or disability scores (i.e., physical de-conditioning). Further examination of Gatchel’s Model using longitudinal data and additional research of this type is required to understand the relationships between psychological distress variables and pain. These relationships are examined further in subsequent study phases, including longitudinally, in Chapter 6. Gatchel’s variables in combination explained approximately one-third of the variance in each of the disability measures. Contrary to the hypotheses for this research phase, examination of the predictive power of the risk and protective factors revealed that optimism and positive affect were not able to account for variance in disability beyond Gatchel’s variables. This may be partially explained by a possible overlap between some of the items of the CES-D and positive affect and optimism (Pressman & Cohen, 2005). Recall that there were moderate negative correlations between the CES-D and Affect-Balance scale (positive affect; r = .41) and LOT-R (optimism; r = .51). Consistent with study predictions, self efficacy, fear-avoidance beliefs, and the Limiting Activities coping factor were significant predictors of disability. The evidence for perceived social support, the belief that one will not return to work, and the Catastrophising coping factor was mixed. When all the predictors were examined simultaneously, the significant predictor in both models was self efficacy. The Limiting Activities coping factor was a significant predictor of daily Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 163 interference (RMDQ scores) and depression scores was a significant predictor of global disability (GCPS disability estimate). The robustness of these findings is underscored by the consistency in the results of these analyses, which used two different measures of disability as proxy measures of physical de-conditioning. A larger proportion of the variance in the measures of mental deconditioning was explained by the predictor variables, compared to the disability measures. The risk and protective factors which were significant predictors of depression included optimism, positive affect, social support, self efficacy, Influence of Emotion, Task Persistence and Catastrophising. When all predictors were examined simultaneously, optimism, social support, Influence of Emotion and Catastrophising remained significant predictors. When examining anxiety, the following predictors were significant, optimism, social support, self efficacy, fearavoidance beliefs, Limiting Activities, Use of Distraction, Influence of Emotion and Catastrophising. Of these predictors, self efficacy, fear-avoidance beliefs, Limiting Activities, Use of Distraction, Influence of Emotion and Catastrophising remained significant predictors when all predictors were examined together. Finally, whether a community sample could be classified into the three stages of Gatchel’s model in a meaningful way was examined. Two discriminant functions which were able to discriminate between these stages were derived, which provides some support for Gatchel’s stages. Strong optimism and low activity limitations, fear-avoidance beliefs, depression, anxiety, catastrophising, low expectations for a cure and less number of pain sites separated Stage 2 respondents from Stage 3 respondents. However, these results should be interpreted cautiously as the classification scheme derived was likely to be sample specific and limited by the small number of Stage 3 respondents in this sample. Regardless, people with Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 164 chronic pain who would be categorised as being at Stage 3 of Gatchel’s Model may be over-represented in clinical samples. While the numbers of Stage 3 respondents were small in this sample and this possibly influenced the classification scheme, this community sample may reflect the true numbers of people who are severely disabled by chronic pain in the community. In conclusion, this research phase provides the first test of Gatchel’s Model in a community sample. Although only cross-sectional data are presented here, this data offers a preliminary examination of many of the concepts of Gatchel’s Model and some possible extensions that could be made to this model. Based on this data, self efficacy, the Limiting Activities coping factor and the Catastrophising coping factor may be useful additions to assist in explaining the disability that is caused by pain. Although, because these factors were derived from this data, it is not clear how these concepts would be best operationalised in other research. Future research could assess the value of the original Catastrophising subscale of the Coping Strategies Questionnaire and 42-item Chronic Pain Coping Inventory in community samples as the factors derived from these instruments were the most predictive of pain disability. In addition, this data are limited by the manner in which mental and physical de-conditioning were operationalised. While mail questionnaires were used in order to obtain a large non-clinical sample of people with pain, the use of questionnaires for data collection prohibited the collection of objective measures of disability and physical de-conditioning. To partially offset this limitation of the current study, two standardised instruments of disability were collected in an attempt to increase robustness of the findings; however, future research may need to explore other ways of assessing these concepts. Similarly, as the form of mental de-conditioning is Chapter 5: Phase 1 – Baseline Questionnaires (Gatchel’s Model) 165 reliant on characteristics of the individual as well as environmental factors, the measures of mental de-conditioning used in this study do not capture all possible manifestations of mental de-conditioning as described by Gatchel (1991a). Regardless, this study has focused on the two most common manifestations of mental de-conditioning, that is, depression and anxiety to try to capture the majority of mental de-conditioning syndromes. Chapter Summary This study provided an initial examination of Gatchel’s Model in a nonclinical sample. Support was found for some but not all of the concepts and relationships posited by the model. There was no evidence that de-conditioning had increased with time in this sample. However, measures of mental and physical deconditioning were correlated. Some of the risk and protective factors that were explored may be useful extensions to Gatchel’s Model, particular pain-related self efficacy, optimism, social support, and the Influence of Emotion, Catastrophising and the Limiting Activities coping factors. Further examination of this model is needed using a longitudinal analysis; this analysis is presented in Chapter 6. Chapter 6: Phase 2 – Follow-Up Questionnaires 167 CHAPTER 6: PHASE 2 – FOLLOW-UP QUESTIONNAIRES Purpose of the Study The purpose of this research phase was to examine Gatchel’s Model over time using 3-month follow-up data from respondents who had participated in Phase 1 (see Chapter 5). This phase also enabled the influence and predictive value of each of the risk and protective factors on the development of chronic pain and chronic pain disability to be explored further, with the view to proposing possible extensions to Gatchel’s Model. Brief Introduction As identified in Chapter 2, the transition from acute to chronic pain is of particular interest to clinicians in order to implement effective early intervention for individuals at risk of chronic pain (H. I. Andersson, 2004; Elliott et al., 2002). Gatchel’s Model (1991a; see also Gatchel, 2005) provides a framework in which to examine the transition from acute to chronic pain. In brief, Gatchel’s Model describes three stages that individuals who have a serious pain experience move through, each with worsening psychological dysfunction and physical disability. According to this model, two processes, mental and physical de-conditioning, act in tandem as an individual moves through the three stages. As described in Chapter 5, a number of predictions can be made on the basis of Gatchel’s Model. These include the assumptions that: 1) pain duration should be positively correlated with the level of physical disability and psychological distress experienced; 2) depressive symptoms and pain-related anxiety (used to assess mental Chapter 6: Phase 2 – Follow-Up Questionnaires 168 de-conditioning) and disability (physical de-conditioning) should increase for those respondents who still have pain from baseline to 3-month follow-up as mental and physical de-conditioning worsens; and 3) because physical and mental deconditioning processes are linked, changes in mental de-conditioning variables should be associated with changes in physical de-conditioning variables and vice versa. In addition to Gatchel’s Model, other psychosocial factors have been identified as risk factors for developing chronic pain disability; either continued report of pain in acute conditions or worsening disability in chronic conditions. As discussed in Chapter2, these include pain intensity (Linton & Hallden, 1997; Reid et al., 1997; Sieben et al., 2005; White et al., 1997), the belief that pain will become persistent (Linton & Hallden, 1997; Schultz et al., 2004; White et al., 1997), catastrophising (Burton et al., 1995; Keefe et al., 2004; Picavet et al., 2002) and fearavoidance beliefs (Buer & Linton, 2002; Ciccone & Just, 2001; Crombez et al., 1999; Fritz et al., 2001; Grotle, Vollestad, Veierod, & Brox, 2004; Klenerman et al., 1995; cf Sieben et al., 2005). In Phase 1 of this research, some evidence was found for high fear-avoidance beliefs and catastrophising in separating respondents at Stage 2 (chronic pain) of Gatchel’s Model with respondents from Stage 3 (disabled by chronic pain). In terms of physiological factors, there is also evidence that a greater number of pain sites in the acute stage (Linton & Hallden, 1997) or a greater number of previous episodes of this type of pain condition (Sieben et al., 2005) is related to continued pain26. The influence of these variables will be able to be explored with 26 A number of demographic variables have also been linked to increased risk of chronic pain development (see Chapter 2). However, these are not included here because this sample may be biased towards female sex and older participants (see Chapter 4). Chapter 6: Phase 2 – Follow-Up Questionnaires 169 respondents who were classified as having acute pain at Phase 1 and continue to report pain at Phase 2. In addition, factors that may act as protective against chronic pain development have been identified in the context of chronic pain adjustment or generally better health outcomes. These variables include active coping strategies (Jensen & Karoly, 1991; Jensen et al., 1991; Koleck et al., 2006; McCracken et al., 2005; cf Revenson & Felton, 1989), stronger pain-related self efficacy (Arnstein et al., 1999; Sharma et al., 2003), specific pain beliefs (Jensen & Karoly, 1992), positive affect (Zautra et al., 2005), optimism (Novy et al., 1998; Scheier & Carver, 1992), and perceived social support (Bergman et al., 2002; Evers et al., 1998; Evers et al., 2003). The results of Phase 1 support that high optimism and low activity limitations (a passive coping response) are able to separate respondents with chronic pain from those who are disabled by chronic pain. Further, self efficacy was a significant predictor of disability whereas the evidence for perceived social support was mixed. While the previous research phase offered a cross-sectional examination of these variables, a longitudinal design (necessary to examine the predictive validity of these factors over time) has not been used previously. This is especially important as these risk and protective factors might also contribute to an expansion or refinement of Gatchel’s Model by explaining why some people progress through the model as predicted and others do not. Therefore, the aim of this study was to examine the three hypotheses made on the basis of Gatchel’s Model using a longitudinal design. Secondary aims of this study included 1) exploring the development of chronic pain with respondents who had acute pain during Phase 1 Chapter 6: Phase 2 – Follow-Up Questionnaires 170 and continued to have pain at follow-up, and 2) assessing the predictive value of risk and protective factors for continuing pain in the chronic pain sample. Method Sample Eighty-two percent (N = 302) of the Phase 1 participants with acute or chronic pain nominated to be contacted for the follow-up phase of the project. Follow-up questionnaires were returned by 218 respondents (59.40% of the original acute or chronic pain respondents; 72.19% of those consenting to follow-up). Most follow-up questionnaires (n = 184) were received after the initial mail-out; a further 34 participants returned a completed questionnaire after a reminder letter was mailed (reminders were mailed out to non-responders 4 weeks after the initial mail-out). Participants were from across all 10 postcode areas. From the acute pain subgroup, there were 28 participants (59.57%) who responded at follow-up (10 with continued pain and 18 for whom their pain had resolved). From the chronic pain subgroup, there were 190 with chronic pain (59.38%) at baseline who responded at follow-up; 163 continued to report pain at follow-up and 27 reported that their pain had resolved. Figure 9 presents a flowchart of how the pain groups were classified and the number of people in each pain group. As can be seen in Figure 9, participants were divided into four categories – new chronic pain (N = 10), resolved acute pain (N = 18), continuing chronic pain (N = 163) and resolved chronic pain (N = 27). The demographical information for each group is presented in Table 33. As can be seen, respondents in each category were similar to the Phase 1 subgroup from which they originated: the new chronic and resolved acute pain groups were similar Chapter 6: Phase 2 – Follow-Up Questionnaires 171 to the Phase 1 acute pain subgroup and the continuing chronic pain and resolved chronic pain groups were similar to the Phase 1 chronic pain subgroup. Phase 1 sample (used to examine Gatchel’s Model) BASELINE 47 ACUTE 320 CHRONIC 19 lost at follow-up FOLLOW-UP 130 lost at follow-up 10 NEW CHRONIC PAIN 18 RESOLVED ACUTE PAIN 163 CONTINUED CHRONIC PAIN 27 RESOLVED CHRONIC PAIN Figure 9. Flowchart of questionnaires returned. Table 33 Demographic Characteristics of the Phase 2 Sample (N = 218) New chronic Resolved Continuing Resolved pain acute pain chronic pain chronic pain (N = 10) (N = 18) (N = 163) (N = 27) 49.8 ± 14.2 55.7 ± 14.3 54.1 ± 17.7 Age in years (mean ± SD) 53.6 ± 8.2 Female (%) 70 50 60.7 59.3 Primary school 0.0 0.0 10.6 3.7 Year 10 40.0 17.6 31.9 22.2 Year 12 10.0 11.8 6.9 18.5 TAFE or equivalent 0.0 23.5 30.0 37.0 University 50.0 47.1 20.6 18.5 Partnered 60.0 88.2 67.5 74.1 No partner 40.0 11.8 32.5 25.9 Education (%)^ Relationship status ^ Does not total to 100% due to missing data Chapter 6: Phase 2 – Follow-Up Questionnaires 172 Measures Follow-up questionnaires contained four of the established self-report instruments used for Phase 1 (i.e., GCPS, RMDQ, CES-D and PASS) in addition to an item asking whether pain was still present. For greater detail about each of these measures please refer to Chapter 3. In addition, the measures collected in Phase 1 and the coping factor scores were used as predictors in these analyses (see Chapter 5). Statistical Analysis The same preliminary analyses as were used in Phase 1 (see Chapters 4 and 5) were calculated. Cronbach’s alpha was calculated for each scale prior to missing data analysis. Table 34 shows, similar to the reliability calculations conducted with the baseline data; the internal consistency of the scales at follow-up was excellent. Table 34 Internal Consistency for each of the Scales at Phase 2 Phase 2 (n = 218) α Scale Graded Chronic Pain Scale Pain intensity .85 Disability Estimate .93 Roland & Morris Disability Questionnaire .90 Center for Epidemiological Studies–Depression scale .91 Pain Anxiety Symptoms Scale-20 .94 The same basic approach to missing data analysis and imputation used in Chapters 4 and 5 was used in Phase 2. Table 35 displays the minimum number of Chapter 6: Phase 2 – Follow-Up Questionnaires 173 items required in each scale for missing data to be replaced and the number of replacements made (<1.5% for any scale). Table 35 Missing Data Imputed (N = 218) 7 # items - minimum available data required (70%) 5 # item replacements made 3 CES-D 20 14 30 0.69 PASS 20 14 31 0.71 Scale # items GCPS % possible replacements a 0.19 Note. GCPS: Graded Chronic Pain Scales, CES-D: Center for Epidemiologic Studies-Depression, PASS: Pain Anxiety Symptoms Scale a % of possible replacements = (# replacements /N x # items in scale) x 100 Results As the primary purpose of this study was to examine the key concepts of Gatchel’s Model using a longitudinal design, these results are presented first. The psychosocial correlates of the development of chronic pain were then explored, by focussing on the respondents who had acute pain at Phase 1 which was still present at follow-up (and therefore considered chronic pain at Phase 2). Next, the predictive value of the risk and protective factors for continuing pain was determined. Finally, the course of chronic pain was plotted using measures of depression, anxiety, daily interference, global disability, and use of coping strategies. Examining Gatchel’s Model Because Gatchel’s Model deals primarily with people who continue to have pain, respondents were selected for the following analyses if they reported that their pain was still present at follow-up. Use of this criterion resulted in a sample of 173 Chapter 6: Phase 2 – Follow-Up Questionnaires 174 participants – called the “CHRONIC sample” – consisting of the continuing chronic pain (N = 163) and the new chronic pain (N = 10) participants. Demographic information is provided in Table 36. The CHRONIC sample was similar to the total sample described in Phase 1 (see Chapter 4). The sample consisted of more women and the majority lived with an intimate partner. Table 36 Demographic Characteristics of the CHRONIC sample (N = 173) Age (years) 55.7 ± 14.0 Female (%) 61.3 Education (%)^ Primary school 9.8 Year 10 31.8 Year 12 6.9 TAFE or equivalent 27.7 University 22.0 Relationship status Partnered 67.1 No partner 32.9 ^ Does not total to 100% due to missing data Initially, analyses were undertaken to examine the relationships between Gatchel’s variables and assess changes over time. The correlation analyses and repeated measures t-tests are presented next. Correlation Analyses for Gatchel’s Variables The key elements of Gatchel’s Model – pain duration, disability, depressive symptoms and pain-related anxiety – were examined using correlation analyses. As described in Chapter 5, pain duration was positively skewed. However, correlation Chapter 6: Phase 2 – Follow-Up Questionnaires 175 analysis using a square root transformation resulted in the same results as correlation analysis using the original variable. Therefore, the results using the original variable are reported. Correlations were conducted first using the Phase 1 data and then using the Phase 2 data to compare whether the correlations between the variables changed as pain became chronic or more established (see Table 37). Analyses revealed that pain duration was not related to any of the de-conditioning variables. As in Phase 1, depression and anxiety scores were highly intercorrelated. At Phase 2, the two disability measures and pain intensity were also highly intercorrelated (r ≥ .55). There were moderate positive correlations among the other variables. Table 37 Correlations between Pain Duration and Measures of Gatchel’s Variables at Baseline (shaded) and Follow-Up (unshaded) for Chronic Pain Respondents (N = 173)^ Daily Pain Overall interfer. intensity disability -.027 -.022 .034 -.015 1 .673** .440** .444** .555** .008 .702** 1 .487** .508** .592** Daily interference .021 .471** .572** 1 .444** .560** Pain Intensity .073 .453** .427** .550** 1 .585** Global disability -.021 .561** .569** .697** .650** 1 Duration Depression Anxiety 1 -.057 Depression -.011 Anxiety Duration Note. Depression: Center for Epidemiologic Studies – Depression, Anxiety: Pain Anxiety Symptoms Scale, Daily interference: Roland Morris Disability Questionnaire, Pain intensity: GCPS Graded Chronic Pain Scales – Intensity estimate, Global disability: GCPS Graded Chronic Pain Scales – Disability estimate ^ The value of N varies due to missing data ** p<.01 Chapter 6: Phase 2 – Follow-Up Questionnaires 176 Correlations between Changes in Physical and Mental De-conditioning Gatchel’s Model suggests that mental and physical de-conditioning processes are linked, and influence each other over time. To determine whether changes in mental and physical de-conditioning were related over the three-month follow-up period, correlation analyses were conducted between the change scores for each of the psychological distress variables (depression and anxiety) and the two disability measures. First, change scores were calculated. Positive scores indicate that the score has increased from baseline to follow-up (e.g., depressive symptoms have increased); that is, a worsening of the pain or psychological distress. Negative scores indicate that the score has decreased from baseline to follow-up (e.g., depressive symptoms have decreased). While the value of the mean change on each of the measures was small27, the change scores were normally distributed with an adequate range of scores. Table 38 shows the correlations between the change scores for the four deconditioning variables – depression (CES-D), anxiety (PASS), daily interference (RMDQ) and global disability (GCPS disability estimate). To control for familywise error rates, results were interpreted at an alpha level of .01. There were moderate correlations between the changes in depression and anxiety, and changes in the two disability measures. However, in terms of the relationships between psychological distress and physical disability, only one of the four correlations was significant (see the shaded section of Table 38). The correlation between anxiety and global disability was small but statistically reliable, r = .23. 27 See also the repeated measures t-tests conducted below. Chapter 6: Phase 2 – Follow-Up Questionnaires 177 Changes over Time: Repeated Measures t-Tests Gatchel’s Model suggests that both psychological distress (i.e., mental deconditioning) and disability (i.e., physical de-conditioning) will worsen over time. Repeated measure t-tests were conducted to explore how levels of psychological distress or disability changed over time, for the four measures of de-conditioning (depressive symptoms, pain-related anxiety, daily interference and global disability). Due to the number of analyses, results were interpreted at an alpha level of .01 to minimise the rate of type I error. Table 38 Correlation Matrix for Changes Scores on Psychological and Disability Measures for Chronic Pain Respondents (N = 173)^ CES-D change PASS change CES-D change PASS change RMDQ change Disability est. change 1 .333** .154 .217 1 .121 .229* 1 .306** RMDQ change Disability estimate change 1 Note. CES-D Center for Epidemiologic Studies – Depression, PASS Pain Anxiety Symptoms Scale, RMDQ Roland Morris Disability Questionnaire, GCPS Graded Chronic Pain Scales & Disability estimate ^ The value of N varies due to missing data * p<.01 ** p<.001 The results indicated that there was a small but statistically significant decrease in depression scores from baseline to follow-up (see Table 39) but no change in anxiety scores. In terms of disability, there were no changes in daily interference over time. However, global disability decreased from baseline to follow-up by approximately 5 points, on average. Table 39 Comparing Gatchel’s Variables between Baseline and Follow-up data collection for the CHRONIC sample (N = 173) Baseline Dependent variables 3-month Follow-up Test of Significance Possible score range M SD M SD Depression (CES-D) 18.19 12.61 16.61 11.53 t (163) = 2.60, p = .010* 0-60 Pain-related anxiety (PASS) 34.25 21.57 32.19 21.33 t (169) = 2.17, p = .032 0-100 Daily interference (RMDQ) 8.68 5.83 8.68 5.66 t (172) = 0.02, p = .984 0-24 Global disability (GCPS Disability estimate) 46.88 27.28 41.34 26.21 t (158) = 3.93, p < .001* 0-100 * Statistically significant using Bonferroni adjustment (α = .0125) Table 40 Frequencies (%) of GCPS Classification Changes for Chronic Pain Respondents Classification change N % 3 grade decrease 2 1.2 2 grade decrease 9 5.2 1 grade decrease 40 23.1 No change 65 37.6 1 grade increase 13 7.5 2 grade increase 1 0.6 Note. % does not sum to 100% because 43 respondents did not have change scores calculated. Grade decreases indicate that respondents had a reduction in the severity of their pain. Grade increases indicate that respondents’ pain worsened. Chapter 6: Phase 2 – Follow-Up Questionnaires 179 To further explore the impact that the reduction in disability estimate scores had, if any, on GCPS classification scores, change scores for the GCPS classification were calculated and frequency statistics examined. Respondents’ changes in disability classification ranged from a decrease of three classification levels to an increase of two classification levels. Table 40 shows the frequency and proportion of respondents whose GCPS classification changed over time. As can be seen, even though all of these participants had chronic pain28, approximately 29% had decreased pain intensity29 and/ or disability which resulted in a less severe classification at follow-up. Regardless, the classification for the largest number of respondents did not change (37.6%). Only 8% of the respondents were classified at a higher level (i.e., more disabled). Predicting the Development of Chronic Pain One aim of this research was to examine the predictors of the development of chronic pain from acute pain. However, thorough statistical analysis was not possible due to the small numbers of respondents with acute pain (n = 47), and even smaller numbers of people with acute pain who responded at follow-up (n = 28). Only 10 respondents with acute pain at baseline reported pain at follow-up. Due to the small numbers, only descriptive information and preliminary univariate analyses are reported. This information is presented to offer preliminary data about who develops chronic pain in a community sample. The new chronic cases were compared with the acute resolved sample on demographic data. Chi-square analyses were used for categorical variables (gender, 28 These analyses were also conducted with the continuing chronic pain respondents only to rule out the influence of the acute to chronic transition period on the GCPS classifications; the results were consistent with that reported above. 29 Changes in pain intensity were also examined. On average, pain intensity reduced by 7 points on the 100-point scale from baseline to follow-up, t (171) = 6.10, p <.001. Chapter 6: Phase 2 – Follow-Up Questionnaires 180 marital status, education and location). Independent group t-tests were conducted for the continuous variables (age). Because of the small sample sizes, these analyses should be considered indicative only; an alpha level of .1 was used. To summarise, new chronic cases (n = 10) were mostly women and were aged 43 to 66 years. All had completed at least Year 12 education; half had completed university education. Just over half lived with an intimate partner. Six participants lived in regional or rural Queensland. In terms of the demographic characteristics of this group, they were similar to the respondents with resolved acute pain (n = 18) with regard to gender (χ² (1, n = 28) = 1.05, p =.306), age (t (26) = .71, p =.485), education (χ² (3, n = 27) = 3.60, p =.309) and relationship status (χ² (1, n = 27) = 2.90, p =.088); see Table 33 on page 170. However, new chronic pain participants were more likely to be from a rural area (60.0% vs. 5.6%), χ² (1, n = 28) = 10.16, p =.001. Descriptive pain data are presented for the new chronic pain participants. Table 41 provides a description of each of these participants. Independent group ttests were conducted to compare the people with acute pain who still had pain vs. those who did not have pain at 3 months; only statistically significant differences are discussed. The pain conditions of the group varied in terms of site of pain and number of pain sites. New chronic pain participants had a greater number of pain sites (3.3 vs. 1.5) than resolved acute participants at baseline, t (26) = 1.80, p =.005. Over half experienced pain every day. Pain duration at baseline ranged from 1 week to 3 months. None of these participants indicated having a previous pain episode of this type. This was different from the acute resolved respondents who had an average of 1.12 previous episodes of pain, t (16) = -1.12, p =.027, equal variances not assumed. Table 41 Details of the Participants who transitioned from Acute to Chronic Pain (N = 10) ID Gender Marital Education Age status Home Pain site Diagnosis postcode # Pain Pain # of Depression sites frequency duration previous score episodes 92 Female Partnered Tertiary 43 4020 Shoulder/s _ 3 Everyday 7 days 0 10 267 Male Divorced Tertiary 48 4129 Head Sinus 2 Most days 2 months _ 47* 301 Male Divorced Year 10 63 4507 Shoulder/s _ 1 Everyday 3 months 0 3 345 Female Partnered Tertiary 60 4507 Leg/s _ 5 Everyday 14 days 0 9 626 Female Divorced Year 10 48 4869 _ 8 Everyday 1 month 0 55* 644 Female Partnered Tertiary 51 4741 Leg/s 4 Most days 2 months _ 42* 664 Female Partnered Year 12 47 4869 Head Viral throat infection that attacked all joints Sciatic & work-related stress _ 3 Everyday 14 days _ 34* 711 Female Partnered Year 10 62 4717 Feet _ 1 Everyday 3 months _ 7 750 Male Partnered Year 10 66 4869 Neck 3 Most days 10 days _ 11 815 Female Divorced Tertiary 48 4741 Head Disc in spine slips out of place Occipital neuropathy & ear infection 3 Most days 2 months _ 40* * indicates that CES-D (depression) score was above the cut-off score for a depressive disorder Chapter 6: Phase 2 – Follow-Up Questionnaires 182 The two groups were compared on baseline measures of pain duration, pain intensity, disability, pain-related anxiety, fear-avoidance beliefs, the belief that one would not return to work, pain-related self efficacy, optimism, social support and positive affect. Means and standard deviations are presented in Table 42. Only on depressive symptoms were the groups different, t (11.10) = 2.145, p = .055, equal variances not assumed. On average, there was a 14 point difference on the CES-D; people who continued to report pain at follow-up (M = 25.8; SD = 19.6) reported greater baseline depressive symptoms than people whose pain did not continue (M = 11.8; SD = 8.6). As the possible range on the CES-D is 0-60, this would seem to represent a clinically relevant improvement in depressive symptoms. Predicting Chronic Pain Participants’ Pain Outcome at Follow-up The predictive value of the variables from Gatchel’s Model and the risk and protective factors were investigated with regard to predicting continued chronic pain at Phase 2. To examine these variables, the continuing chronic pain sample (N = 163) was compared with the resolved chronic pain sample (N = 27). Resolved vs. Continued Chronic Pain A binary logistic regression was chosen to determine if substantial independent contributions to the continued presence of pain could be identified amongst the proposed risk and protective factors. The outcome variable was presence of pain at 3-month follow-up. The predictors were socio-demographic variables (gender, whether partnered or not, education level, and age), pain variables (number of previous episodes of this type of pain, whether respondents’ employment had been affected by pain, whether pain was daily or not, and pain duration), Chapter 6: Phase 2 – Follow-Up Questionnaires 183 Gatchel’s de-conditioning variables (depression, anxiety, and disability), and risk and protective factors (fear-avoidance beliefs, the belief that one will not return to work, self efficacy, optimism, perceived social support, positive affect, and the coping factors); all predictor variables were from Phase 1 data. Table 42 Comparison of Predictor Variables between the new Chronic Pain Participants (N = 10) and Resolved Acute Participants (N = 18) Predictor variables New Chronic Pain Resolved Acute Participants (N = 10) Participants (N = 18) Test of Significance Mean SD Mean SD Pain duration .12 .09 .10 .09 t (26) = .528, p = .602 Pain intensity 63.67 21.69 56.48 16.98 t (26) = .972, p = .304 Global disability 38.33 32.63 38.52 23.35 t (26) = -.017, p = .986 Daily interference 7.2 6.39 7.22 5.15 t (26) = -.010, p = .992 Depression 25.80 19.60 11.76 8.64 Anxiety 36.60 24.21 27.41 16.91 t (11.10) = 2.15, p = .055 ^ t (25) = 1.161, p = .257 Fear-avoidance beliefs 29.30 16.99 29.22 15.59 t (26) = .012, p = .990 Belief that one would not return to work Self efficacy .60 1.90 .11 .32 42.70 17.94 46.12 12.38 t (9.29) = .808, p = .439^ t (26) = -.586, p = .563 Optimism 15.10 6.12 15.72 5.63 t (26) = -.272, p = .788 Social support 5.19 1.60 5.84 1.23 Positive affect 3.22 1.56 3.65 1.41 t (26) = -1.195, p = .243 t (24) = -.704, p = .488 Note. Pain intensity: GCPS Graded Chronic Pain Scales – Intensity estimate, Global disability: GCPS Graded Chronic Pain Scales – Disability estimate, Daily interference: Roland Morris Disability Questionnaire, Depression: Center for Epidemiologic Studies – Depression, Anxiety: Pain Anxiety Symptoms Scale, Fear-avoidance beliefs: Fear-Avoidance Beliefs Questionnaire, Self efficacy: Pain Self Efficacy Questionnaire, Optimism: Life Orientation Test – Revised, Social support: Multidimensional Scale of Perceived Social Support, positive affect: Affect-Balance Scale ^ Equal variances not assumed Univariate analyses were conducted between each predictor variable and presence of pain to identify the important predictors for entry into the binary logistic Chapter 6: Phase 2 – Follow-Up Questionnaires 184 regression whilst ensuring adequate power30. Predictors that were associated with the presence of pain at an alpha level of .1 were included in the final binary logistic regression. The results of these analyses, chi-square tests for categorical variables and t-tests for continuous variables are presented in Tables 43 and 44, respectively. The final binary logistic regression included a subset of the predictors stated above, namely pain variables (number of previous episodes of this type of pain, whether pain was daily or most days and pain duration), key concepts from Gatchel’s Model (anxiety and disability), and risk and protective factors (fear-avoidance beliefs, the belief that one will not return to work, self efficacy, social support, Limiting Activities and Catastrophising). These predictors were entered into the model in three steps – pain variables, Gatchel’s variables, and the risk/ protective variables in order to examine the relative variance explained by each group of variables. Results are expressed as relative odds of presence of pain and associated 95% confidence intervals (CI). Odds ratios of 1.5 or higher for risk factors, or equivalently, 0.67 or lower for protective factors, are reported as contextually meaningful effect sizes. Statistical significance using an alpha level of .05 is also reported. Contribution to variation in presence of pain was described using changes in the Nagelkerke’s pseudo-R² statistic between the models. See Table 45 for these results. Only one of the pain variables and one of the protective factors were significant predictors of continuing pain when assessed using this multivariate approach. None of Gatchel’s variables were significant predictors when the full set of predictors was considered simultaneously. Respondents whose pain was present everyday at baseline were at increased risk of continuing pain at follow-up (ORadj = 30 There was insufficient power to enter all predictor variables into the binary logistic regression analysis. Table 43 Univariate tests of Categorical Predictor Variables (N = 190) Predictor variable Gender Relationship status Education # of pain sites Pain had affected employment Pain constancy Disability classification Category levels Pain resolved (%) Pain continued (%) 14.7 13.9 15.4 11.7 5.6 10.5 31.3 17.2 13.2 22.7 14.9 5.9 16.1 8.1 23.1 9.6 34.4 11.8 12.9 4.5 85.3 86.1 84.6 87.3 94.4 89.5 68.8 82.8 86.8 77.3 85.1 94.1 83.9 91.9 76.9 90.4 65.6 88.2 87.1 95.5 Male Female Living with partner No partner Primary school Year 10 Year 12 TAFE Tertiary 1 2-3 4+ No Yes Not everyday Everyday Grade I Grade II Grade III Grade IV ^Variables were chosen for inclusion in the logistic regression model if p < .1 * indicates the variable was included in the logistic regression model Test of significance p^ χ² (1) = 0.02, n = 190 .884 χ² (1) = 0.47, n = 190 .495 χ² (4) = 5.94, n = 187 .204 χ² (2) = 5.53, n = 189 .063* χ² (1) = 1.59, n = 186 .216 χ² (1) = 6.37, n = 190 .012* χ² (3) = 14.44, n = 183 .002* Table 44 Univariate tests of Continuous Predictor Variables (N = 190) Predictor variable Possible Pain resolved (N = 27) Pain continued (N = 163) Test of significance p^ score range Mean SD Mean SD Age _ 54.07 17.66 55.84 14.24 t (186) = -5.77 .565 Pain duration _ 5.69 8.25 9.42 9.32 t (36.79) = -2.09 .044* Depression (CES-D) 0-60 15.46 12.20 17.69 11.95 t (178) = -.879 .381 Anxiety (PASS) 0-100 21.68 15.96 34.36 21.66 t (39.21) = -3.50 .001* Daily interference 0-24 5.15 2.90 8.77 5.80 t (67.04) = -5.03 .001* Self efficacy (PSEQ) 0-60 48.96 10.80 41.30 13.37 t (38.46) = 3.24 .002* Fear-avoidance beliefs (FABQ) 0-66 22.85 15.22 33.73 16.84 t (179) = -3.14 .002* Belief that will not return to work 0-6 1.04 1.97 2.32 2.68 t (44.49) = -2.95 .005* Optimism (LOT-R) 0-60 15.96 4.05 15.12 5.43 t (43.38) = .94 .351 Positive affect 0-5 3.35 1.60 3.16 1.54 t (179) = .56 .574 Social support 1-7 4.80 1.74 5.40 1.53 t (186) = -1.84 .068* Limiting activities _ -.21 .68 .11 .99 t (40.39) = -.204 .048* Use of Distraction _ .31 1.04 .15 .99 t (176) = .76 .450 Influence of Emotion _ -.21 .92 -.01 1.08 t (176) = -.85 .398 Task persistence _ -.33 1.31 .12 .98 t (27.19) = -1.61 .118 Catastrophising _ -.27 .87 .30 1.00 t (176) = -2.65 .009* No Expectation of a cure _ -.25 1.03 .09 .93 t (176) = -1.64 .103 ^Variables were chosen for inclusion in the logistic regression model if p < .1 * indicates the variable was included in the logistic regression model Table 45 Results of the Binary Logistic Regression Predicting Resolved (n = 27) vs. Continued Chronic Pain (n = 163)^ Categories N % pain Crude OR 1 site 29 77.3 2-3 sites 67 4 + sites Not every day Adjusted OR 95% CI 1.00 1.00 Referent 85.1 0.81 2.25 0.45-11.30 41 94.1 2.19 8.95 0.89-90.43 48 76.9 1.00 1.00 Referent Every day 89 90.4 1.86 6.43* 1.30-31.95 _ 154 _ 0.07 1.08 0.98-1.17 Anxiety _ 186 _ 0.03 1.03 0.97-1.10 Daily interference _ 190 _ 0.22 1.24 0.95-1.63 Disability classification Grade I 23 65.6 1.00 1.00 Referent Grade II 57 88.2 0.34 1.40 0.26-7.70 Grade III 23 87.1 -2.75 0.06 0.00-1.44 Grade IV 34 95.5 -0.61 0.54 0.01-20.63 Pain variables Number of pain sites Pain constancy Pain duration Gatchel’s Model variables Protective Factors Self efficacy _ 188 _ -0.04 0.96 0.85-1.08 Social support _ 188 _ 0.57 1.75* 1.12-2.75 Fear-avoidance beliefs _ 181 _ 0.03 1.03 0.97-1.11 Belief that will not return to work _ 183 _ -0.05 0.96 0.57-1.59 Limiting Activities _ 178 _ -0.89 0.41 0.12-1.37 Catastrophising _ 178 _ 0.33 1.39 0.69-2.82 ^ There were 53 missing cases *p < .05 Chapter 6: Phase 2 – Follow-Up Questionnaires 188 6.43; CI 1.30-31.95), as were respondents who had greater perceived social support (ORadj = 1.75; CI 1.12-2.75). When examining each step of the model, pain variables explained approximately 20% of the variance in the presence of pain at follow-up, with Gatchel’s variables contributing an additional 17%, and the risk and protective factors contributing an additional 10%; the total model accounted approximately 47% of the variance in the presence of pain at follow-up. Discussion Examining Gatchel’s Model The primary aim of this study was to examine the elements of Gatchel’s Model over time in a non-clinical sample of people with pain. The main premise of the model is that people with pain will worsen over time in terms of their physical disability (termed physical de-conditioning) and psychological distress (termed mental de-conditioning) until they reach a state of chronic pain disability. A number of predictions can be made on the basis of Gatchel’s Model, which are considered below. First, as the stages of the model are temporally defined, pain duration is expected to be associated with the level of physical disability and psychological distress experienced. Second, because physical and mental de-conditioning are predicted to worsen over time, depressive symptoms and pain-related anxiety (indicators of mental de-conditioning) should increase from baseline to 3-month follow-up. Concurrently, it was expected that disability would worsen. Finally, Gatchel’s Model suggests that physical and mental de-conditioning processes are linked, and consequently it was predicted that changes in these variables would be associated with changes in the other. Chapter 6: Phase 2 – Follow-Up Questionnaires 189 The results of this study were, in the main part, inconsistent with the above predictions. Contrary to the first prediction, pain duration was not related with the de-conditioning variables at baseline or follow-up, even when examining only people with chronic pain. Contrary to the prediction that de-conditioning would worsen over time, there were no changes on some de-conditioning variables and decreases on other deconditioning variables. Small reductions were seen in depressive symptoms while there was no change in pain-related anxiety from baseline to 3-month follow-up (rather than increases on these variables). There was also no change in the daily interference levels. Overall disability decreased from baseline to follow-up. When the change in disability classification was examined in more detail, it showed that for many respondents, their level of disability had not changed. However, for approximately 29% of these respondents, their disability classification had dropped at least one level. Very few respondents became more disabled during the 3-month follow-up period. Finally, correlation analyses between the change scores on depressive symptoms, pain-related anxiety, daily interference and global disability showed that while change scores were related in the expected direction (i.e., they increased over time), the associations were small. However, the measures of mental and physical de-conditioning were significantly associated with each other at baseline and follow-up. This offers partial support for Gatchel’s Model, as mental and physical conditioning are posited to be linked. While it appears that Gatchel’s Model does not provide an adequate framework for the acute to chronic pain transition in this community sample, a number of alternate explanations for these results should be considered. It is Chapter 6: Phase 2 – Follow-Up Questionnaires 190 possible that the data suffered from restriction of range; that is, there was not sufficient variability in the data to detect relationships. This seems unlikely because, although the majority of these respondents were classified as having chronic pain at baseline, the chronic sample examined here also contained the 10 new chronic cases. In addition, pain duration ranged from 13 weeks to 37 years. A second alternate explanation is that the follow-up period used in this research (i.e., 3 months) may have been insufficient to capture changes in mental and physical de-conditioning. This may be likely issue in the current sample because the majority of the sample has experienced chronic pain for many years (see Table 10 in Chapter 4). This suggestion may explain the variables that did not change (pain-related anxiety and daily interference). However, it does not account for the considerable portions of the sample who experienced decreased overall disability or fewer depressive symptoms. These decreases in some measures of mental and physical de-conditioning provide some evidence for three months as a sufficient follow-up period for change to occur. While the analyses undertaken to explore Gatchel’s variables were conducted using a subset of the sample who continued to experience chronic pain at follow-up, (similar to the groups reported by Gatchel), the nature of this community sample may have been different to those seen by Gatchel and those described as providing support for this model. Regardless, as one of the aims of this research was to assess the value of Gatchel’s Model in a community sample, it would seem that it does not provide a good fit with the experience of non-clinical samples. Nonetheless, as Gatchel’s Model was first developed with references to patients with low back pain, these analyses were re-run with only those respondents who nominated the low back as their primary pain site. The results of these analyses Chapter 6: Phase 2 – Follow-Up Questionnaires 191 were mostly consistent with that already presented (so the data are not shown; see Appendix E for these results). That is, pain duration was not related with the deconditioning variables at baseline or follow-up. Nor were the changes in mental and physical de-conditioning scores correlated. However, there was one exception; there was no change in depression, anxiety or disability scores for those with low back pain. This may indicate that a 3-month follow-up period is insufficient to see the deconditioning effects of low back pain. Alternatively, there may have been insufficient power to detect an effect as these analyses utilised a smaller sample. Finally, as discussed in Chapter 5, this data may be limited by the manner in which mental and physical de-conditioning were operationalised. Objective measures of disability and physical de-conditioning were not collected and not all of the possible manifestations of mental de-conditioning were assessed. In summary, the results are not consistent with Gatchel’s Model as a helpful way of understanding the acute to chronic pain transition, in particular with pain at other sites than the lower back, in a community setting. These results also indicate that there is considerable movement in the pain experience and level of disability of non-clinical samples, at least in the relative short-term (that is, 3 months). Pain Outcome at Follow-Up Predicting Chronic Pain Development Unfortunately, the predictive value of the proposed risk and protective factors for the development of chronic pain could not be assessed using multivariate techniques due to the small sample size of those who reported acute pain at baseline, and the attrition rate at follow-up. Results indicated that the characteristics of the 10 people, who had acute pain at baseline and continued to report pain at follow-up, Chapter 6: Phase 2 – Follow-Up Questionnaires 192 were not different from those whose pain resolved except for residential location. Participants who developed chronic pain were more likely to reside in a rural location. This finding is consistent with a North American study which found that rural residents have a higher prevalence of pain (Hoffman et al., 2002); perhaps rural residents are more likely to develop chronic pain once an injury has occurred. One explanation for this increased risk relates to limited access to medical care (compared to urban residents) for rural residents; Australian data shows that rural areas have been associated with difficulty accessing healthcare (Public Health Division, 2000). In addition, North American research shows there are few pain specialists in rural areas (Breuer, Pappagallo, Tai, & Portenoy, 2007), a similar situation may also be true in Australia. The pain conditions reported by the new chronic pain respondents were highly varied, in terms of site of pain, number of pain sites and pain duration. Those who developed chronic pain reported a greater number of pain sites than the respondents whose pain resolved, which is consistent with previous research (Linton & Hallden, 1997). Interestingly, none of the new chronic pain participants indicated having a previous pain episode of this type. This differed from the acute resolved sample, where respondents were more likely to report having experienced this type of pain previously. It is also inconsistent with research that has found that the presence of a greater number of previous episodes of pain is predictive of chronic pain development (e.g., Sieben et al., 2005). However, over half of the new chronic pain cases did not respond to this item, so this finding should be considered preliminary. For the psychosocial variables, the only difference between the people with acute pain who developed chronic pain and those who did not was the presence of a Chapter 6: Phase 2 – Follow-Up Questionnaires 193 greater number or more severe depressive symptoms at baseline. Examination of the distribution of depression scores for the people who developed chronic pain revealed considerable variance; scores ranged from 3-55 (possible range 0-60) with a bimodal distribution. While caution needs to be exercised when interpreting and generalising these results, they offer preliminary evidence for the influence of depressive symptoms in the early stages of the acute to chronic pain transition for some people only. Significant Predictors of Continuing Chronic Pain In addition to exploring Gatchel’s Model with this community sample, the predictive value of the risk and protective factors was examined, as was the predictive value of demographic and pain variables. While none of the demographic variables predicted continued presence of pain at follow-up, at a univariate level two pain variables were associated with the continuation of pain; respondents whose pain continued were more likely to report their pain was present every day and a longer duration of pain. In terms of Gatchel’s variables, worse disability on both daily interference and global disability and higher anxiety were associated with the continued presence of pain at follow-up. Of the risk and protective factors, continued presence of pain was related to stronger fear-avoidance beliefs, a stronger belief that one would not return to work, greater activity limitations, greater catastrophising and lower self efficacy. However, when the pain variables, Gatchel’s variables, risk variables and protective variables were assessed in combination, only greater social support and pain everyday were the independent predictors of continued presence of pain at follow-up. Previously, White et al. (1997) also found that a constant temporal Chapter 6: Phase 2 – Follow-Up Questionnaires 194 pattern of pain over the initial 3 weeks after hospital admission was predictive of the development of chronic pain in hospitalised patients with acute pain. The current findings indicate that this relationship is true even once pain becomes chronic. The findings for social support are surprising. Perceived social support was included in this research as a protective factor. However, these results suggest that greater perceived social support is a risk factor for continuing pain. In previous studies, the perception of greater social support had been found to be protective against developing more severe pain (H. I. Andersson, 2004; Bergman et al., 2002; Evers et al., 2003) and greater disability (Evers et al., 2003; Sharma et al., 2003) in community samples of people with chronic pain. One explanation for this finding is that because high perceived social support was reported by the majority of the sample, those with the highest scores had support that actually prolonged chronic pain behaviour through secondary reward processes (Jensen et al., 1994). At this stage, these results in the context of our research may be interpreted cautiously as evidence that very high social support is problematic but moderate to high social support is helpful. Alternately, it may be that people with worse pain receive more social support as these data were collected when respondents already had pain. Data collected prior to the onset of chronic pain is required to test these hypotheses. Chapter Summary The results of this study show that similar to the cross-sectional analysis of Gatchel’s Model (see Chapter 5), little support was found for the concepts and relationships predicted by Gatchel’s Model in this community sample. The data provide some evidence for constant pain and higher perceived social support as predictors of continued pain. Higher depression scores and rural location were Chapter 6: Phase 2 – Follow-Up Questionnaires 195 indicated as preliminary predictors of chronic pain development. However, these results are limited by the way in which the de-conditioning syndromes were operationalised. The processes by which these respondents did develop chronic pain or have their pain resolve are still unclear. These issues are examined in Chapter 7, where the results of the Phase 3 are discussed. Chapter 7: Phase 3 – Semi-structured Interviews 197 CHAPTER 7: PHASE 3 – SEMI-STRUCTURED INTERVIEWS Purpose of the Study The purpose of Phase 3 was to use a qualitative approach to further explore the two primary aims of the research (i.e., the experience of pain in a community sample and Gatchel’s Model in a non-clinical sample). A qualitative design was chosen to both capture the respondents’ point of view about their pain as well as enable the underlying processes of the acute to chronic pain transition and the consolidation of pain-related disability to be further explored. Using a qualitative approach as the final research phase also permitted the results of the previous questionnaire phases to be extended and re-examined. Brief Introduction Previously, the rationale for using a mixed-method approach was discussed (see Chapter 3) and the quantitative data were presented in Chapters 4, 5 and 6. The results of Phase 1 support previous research which suggests that 1 in 5 adults experience chronic pain (Blyth et al., 2001). In this community sample, respondents with pain reported significant levels of depression, anxiety and disability, which were comparable to those reported in clinical samples. In terms of Gatchel’s Model (1991a), the results thus far suggest that while respondents at each of the three stages of the model may be able to be distinguished, pain duration is not an important variable for discrimination of these stages. The data supports that mental and physical de-conditioning are correlated. However, changes over time in one de-conditioning type did not correspond with changes in Chapter 7: Phase 3 – Semi-structured Interviews 198 the other. Finally, there was evidence that activity limitations and self efficacy are strongly linked with disability, and perceived social support and constant pain are predictors of continued pain. The current research phase provided an opportunity to explore the experience of pain and Gatchel’s Model from the respondents’ viewpoint. Specifically, this research phase aimed to examine: 1) the aspects of the pain experience that people with pain, particularly chronic pain, believed were important and 2) the key elements of Gatchel’s Model and the presence (or not) of possible risk and protective mechanisms. A secondary aim of this data collection was to use this data to facilitate interpretation of the quantitative data collected in the previous research phases. Method Sample Single semi-structured interviews were conducted with a subset of the original sample of participants with pain (see Chapter 3 and 4 for the full details of the original sample). One hundred and eleven participants consented to be contacted for an interview (50.92 %of 218 participants from Phase 2). The sample was chosen in order to draw on a range of pain experiences. Therefore, contact with participants from all of the pain subgroups (defined in Phase 2) was attempted. The Phase 2 pain subgroups were new chronic pain (N = 10), resolved acute pain (N = 18), original chronic pain (N = 163) and resolved chronic pain (N = 27). Recall that respondents of the previous phases were able to be classified in this way through their pain duration at Phase 1 and the continued presence (or not) of pain at Phase 2. In addition, because the study of anomalous Chapter 7: Phase 3 – Semi-structured Interviews 199 cases can result in an enhanced understanding of a phenomenon (Axinn & Pearce, 2006) and because a major limitation of Gatchel’s Model is that it does not account for recovery from pain, respondents whose pain had resolved were particularly targeted (i.e., resolved acute pain and resolved chronic pain). Of the 41 people31 with whom contact was attempted, approximately 50% (n = 20) proceeded to interview (see Figure 10). Two letters were returned; marked sender not at this address. Telephone contact was attempted on three separate occasions for the remaining 39 participants; contact was made with 26 participants. Non-contact occurred for the following reasons: disconnected telephone, no answer on three separate call attempts and no response to a message left on an answering Participants agreed to follow up contact; n = 111 Letter of invitation mailed; n = 41 Incorrect address; n = 2 Telephone contact attempted; n = 39 Telephone disconnected; n=3 Did not wish to participate; n=4 Contact made; n = 26 No answer; n = 2 Did not attend interview; n=2 Interview conducted; n = 20 Original chronic pain n=7 New chronic pain n=1 Did not return call; n = 8 Resolved acute pain n=4 Resolved chronic pain n=8 Figure 10. Flowchart of the interview sample 31 Due to the discrepancy in the group sizes, all participants from the new chronic pain, resolved acute pain and resolved chronic pain subgroups were contacted initially. From the original chronic pain subgroup, approximately 20% were randomly chosen. A 20% selection was made in order to contact a similar number of participants with original chronic pain (compared to the other three pain subgroups). Chapter 7: Phase 3 – Semi-structured Interviews 200 machine or voicemail service. Of those contacted, four participants did not wish to participate and two agreed to participate but did not attend an interview. The interviews were completed by 12 women and 8 men, with an age range of 42-82 years (median = 54.5 years) (see Table 46 for a detailed demographic and pain profile of each of the interviewees). Thirteen participants were living in a marriage or marriage-like relationship. Participants came from each of the greater Brisbane postcode areas used in the questionnaire phase. Most interviewees (n = 13) still experienced constant or recurrent pain at the time of the interview. The mean number of painful sites was 2.2 (SD = 1.11). The most common sites of primary pain were the leg/s (n = 6), lower back (n = 3) and shoulder/s (n = 3). Pain duration (at questionnaire baseline) ranged from 1 week to 40 years (median pain duration = 1.38 years). Comparisons between those who agreed to participate and those who were invited but did not participate in the interviews, using independent groups t-tests revealed that there were no differences on age (t (39) =.094, p = .926), number of pain sites (t (39) = .992, p = .328), and pain duration (t (39) =.300, p = .765). These comparisons were made using Phase 1 baseline data. There were also no differences between those who agreed to participate and those who did not on their most recent measures of depression (t (39) =.027, p = .979), anxiety (t (38) =-.480, p = .634), global disability (t (38) =-1.43, p = .161) or pain intensity (t (39) =.-1.31, p = .199) collected in Phase 2. These group comparisons suggest that the respondents who participated in the interviews were similar to those who did not proceed to interview when compared on the pain and Gatchel’s variables. Table 46 Profile of Each of the Interviewees Phase 1 data Identifier Gender Phase 2 data Primary pain Pain site duration Pain group Phase 3 data Age (yrs) Primary pain site Description 18 female multiple sites 3 years resolved chronic 55 multiple sites Ongoing recurrent pain 24 male upper back 40 years resolved chronic 60 back Ongoing recurrent pain 92 female shoulder 7 days new chronic 45 lower back/ hip Pain resolved through chiropractic treatment and shoe inserts a 119 female head 2 months resolved acute 63 head Pain resolved 156* Male shoulder 20 years original chronic 59 knee/ shoulder Ongoing constant pain 215 female shoulder 6 years resolved chronic 64 shoulders/ wrist Ongoing recurrent pain 231 male leg 2 months resolved acute 46 leg Pain resolved 244 female arm 8 months resolved chronic 42 arm Pain resolved. 283 female wrist 2 months resolved acute 58 wrist/ shoulder Broken wrist in fall; resolved originally. Some recurrent soreness recently. 305* female leg 13 years original chronic 57 knee Ongoing constant pain 346 male chest 14 years resolved chronic 77 chest Ongoing recurrent pain 355 male leg 20 years original chronic 81 knee Ongoing constant pain Phase 1 data Identifier Gender Phase 2 data Primary pain Pain site duration Pain group Phase 3 data Age (yrs) Primary pain site Description 371 female lower back 2 years original chronic 49 multiple sites Ongoing recurrent pain. Diagnosis of osteoarthritis 406* male leg 5 months original chronic 83 leg / lower back Ongoing constant back pain for 60 years. Some relief for back and leg pain via anaesthetic injected into spine. 424* female hip 9 months original chronic 50 hip/ shoulder Ongoing constant pain 475 female leg 6 months resolved chronic 51 knee Knee still tender; some recurrent episodes 497 male neck 2 years original chronic 54 lower back Ongoing constant pain 557 female lower back 20 years resolved chronic 55 lower back Ongoing recurrent pain 559 female lower back 21 days resolved acute 76 lower back Successful acupuncture treatment 819 male lower back 6 months resolved chronic 53 lower back Successful back surgery Note. Identifiers are used in the Results section to denote from whom the quotes came. *Participant formed part of the pilot testing group a This participant chose to speak about another chronic pain condition (lower back/ hip) which has resolved, rather than her shoulder pain that had also resolved. Chapter 7: Phase 3 – Semi-structured Interviews 203 Procedure Letters of invitation were sent to 41 participants, followed by telephone contact to address any questions regarding participation and to arrange a suitable interview time. As noted in Chapter 3, most interviews were held in private rooms at public libraries or a university campus32. Prior to beginning each interview, it was emphasised to participants that there were no right or wrong answers, and that the aim of the interviews was to obtain their opinions and thoughts. Questions for the semi-structured interviews were generated from Gatchel’s Model and the questionnaire data. In general terms, the prescribed interview questions explored in greater depth the experience of pain and strategies to manage the development of psychological distress and physical disability. Interview questions were designed to be open-ended (see Chapter 3 for a copy of the interview items). Additional prompts were used to elicit greater description of or clarify information that interviewees provided. Participants were also given the opportunity to comment on or re-emphasise any aspect of pain at the close of the interview. This aspect was included as a strategy to improve the accuracy and validity of the interpretations made from this data. Data Coding and Analysis The focus of the analysis of the interview data was to examine, in more detail, individuals’ experience of developing chronic pain, in relation to possible risk and protective mechanisms as well as mental and physical de-conditioning over time. Specifically, the mechanisms by which risk and protective factors have their effect and the interaction between mental and physical de-conditioning, predicted by 32 Recall that one participant’s interview took place in his home (see Chapter 3 for more details). Chapter 7: Phase 3 – Semi-structured Interviews 204 Gatchel’s Model, was also explored. The analysis was ongoing and additional themes evolved during the coding and analysis stages. Data from all 20 interviews were examined together. Initially, Gatchel’s Model and the proposed risk and protective factors that may extend Gatchel’s Model were used as the framework for thematic analysis. A list of Gatchel’s variables was created and all data that referred to aspects of Gatchel’s Model was identified. References to the proposed risk and protective factors - including the variables that were assessed through the questionnaire phase, for example, optimism, social support, or positive affect - were also identified. Additionally, during the coding process other themes in the data were noted and considered as they occurred. As a key aim of the research was to explore aspects or processes that may be important in the experience of chronic pain, which have not been captured in previous research; this process provided an extra richness that was data driven. Analysis of this data was conducted using this deductive framework. The data were considered in light of the results of Phase 1 and 2, and the results of the previous phases were re-examined in light of the data from this phase. Two (10%) of the transcripts were coded by an independent reviewer, experienced in qualitative data analysis. Through discussion of the coding applied and the descriptions of the codes, two codes were identified as vague. These codes were modified accordingly. In addition, this process enabled the interviewer to reflect on the data from another perspective in order to improve the accuracy of the interpretation of the data. Chapter 7: Phase 3 – Semi-structured Interviews 205 Results As per the aims of this research phase, the results are presented in a number of sections. Initially, the experience of pain as described by interviewees is provided. Second, references to the elements of Gatchel’s Model are detailed. Third, an examination of the questionnaire data with consideration of this qualitative data are presented. Additional (data driven) themes are considered throughout. While the data are discussed in sections for the purposes of simplicity, the data was interconnected and overlap is described. The Experience of Pain Descriptions of Pain Some interviewees provided descriptions that were illustrative of various perspectives on pain. These descriptions are presented below. Doing battle. One of the ways that respondents spoke about interacting with pain was suggestive of doing battle. Like battle, participants prepared for pain episodes when triggers for a pain flare-up were present or expected. Respondents seemed fearless of pain if the activity or their goal was worth the pain. Interviewees spoke about the importance of maintaining control over pain. For example, one participant (#305) did not want to take medication because it diminished her ability to stay in control. Similarly, one participant who no longer had pain compared managing pain episodes to managing a business problem; an analogous concept may be applied to planning warfare. Accordingly, pain should be examined and analysed, and the appropriate action steps implemented to remove the problem of pain. Chapter 7: Phase 3 – Semi-structured Interviews 206 I think, like if you’ve got a business problem, I supervise a [large manufacturing] plant … and if I have a problem, you have to solve it professionally. And your pain is a similar type of issue. Attack it like a business problem with bringing in the best advice, taking the right steps, making an action plan, and following it. You have to take [pain] on like a project. [#231, male, resolved leg pain] New love. In contrast, pain was described by another participant as being like new love. While, love has positive connotations (unlike battle), it was the attention consuming aspects of love that aligned with the pain experience. This resemblance is more obvious if the pain is interpreted as a precursor to death or serious injury as it was by this participant. Describing pain, it’s like love. It’s a rather outlandish description. But love is all overwhelming, all possessing. When you fall in love, you can think of one thing only – what a wonderful man, what a beautiful woman. Pain is a bit the same. It overwhelms you. You think of nothing but that pain. It’s uppermost in your mind. [#346, male, chest pain] Lighthouse. The interviewee who described pain like love also described pain as a lighthouse. In conjunction with the overwhelming nature of pain, pain was seen as a life-threatening warning. Consequently, such a warning would compel attention. As above, this point of view was consistent with pain being an antecedent to dying. It’s hard to know how to describe pain. It’s like a lighthouse that shines light on the rocks. It’s a warning. [#346, male, chest pain] Chapter 7: Phase 3 – Semi-structured Interviews 207 Co-existence (with the gods). Finally, a number of interviewees spoke about co-existing with pain. This entailed compromising with the dictations of pain. It reminded the interviewer of living alongside the gods in Greek mythology: the reactions or moods of the gods could be difficult to predict but within that framework, humans do what they can to appease them or to not upset them in the first place. One participant (#557) specified that she did not ignore her pain; neither did she let it totally dictate her life. Through listening to her body and her pain and recognising when her back was tender, this interviewee was able to adjust her activities for that day so that she could still attend another future valuable endeavour in the days to come. A second interviewee described the compromise with pain as follows. So provided I can live a life that is not too debilitating I’ve learned to live with the pain, I suppose, when it happens. And um I’m doing a lot better than a couple of the specialists … [they] suggested that I would be in a wheelchair by the time I was 40, 45 max. Well, I’m well beyond 10 years on that and I’m quite happy to keep out of [a wheelchair] thank you very much. So we’ll see how that goes as well. [#156, male, knee & shoulder pain] Consistent with this view, pain was often discussed in a personified form – pain was able to become upset, to become aggravated and to be vengeful. It seemed important to “respect” pain in order to ease it. [Pain] goes if you don’t keep annoying it [#557, female, back pain] Chapter 7: Phase 3 – Semi-structured Interviews 208 Part of getting older. Participants spoke about some pain and disability as just being part of getting older. Within that framework of becoming more debilitated, pain and some of its associated limitations were viewed as “normal” and “expected”. I just acknowledge that it's now part of arthritis and that obviously I have got arthritis in other parts of my body, not just in that hip … I just accept that it's part of getting older, yeah. I don't let it worry me, much. I just accept it's there. [#559, female, resolved back pain] Influence of Pain on Self Even within some of the descriptions provided above, respondents talked specifically about the influence of their pain on themselves and their lives. The various types of pain (i.e., constant, episodic and resolved) seemed to be related to the influence pain had on the individual. Therefore, participants with each type of pain are grouped together. At the end of this section, two respondents who stood out as suffering with their pain are described. Constant pain “Pain doesn’t rule my life” Respondents, particularly those who experienced constant pain, highlighted the difference between being cautious or careful and managing pain, and conversely, letting pain rule their life. Pain and pain flare-ups were often viewed as inevitable. Interviewees spoke about having to bear their pain and not give up or treating their pain as a challenge to be risen up against. [Apart from your pain, do you think other things have changed for you because you have had these painful experiences?] Yes, only in the way that I can't be as vigorous as what I would do. Like, the bushwalking, I used to be like a little mountain goat, where you can jump from rock to rock … whereas if I do that Chapter 7: Phase 3 – Semi-structured Interviews 209 now, my ankle will give in very quickly; that jarring motion of jumping. So it has, but [pain] doesn't stop me. It doesn't stop me. That's the difference. [#18, female, multiple sites] So I didn’t let that stop me. I did know that it was going to be an issue, so I just planned accordingly. … you look at what’s most important, and you enjoy what you need to do. So I enjoyed that day and dealt with it afterwards. [Pain] doesn’t rule my life but it does sometimes slow it down a little. [#497, male, back pain] Since pain was accepted as part of everyday life, whether an activity would cause pain or not was not a determining factor in decision making. Often interviewees listed activities or roles that they continued to play despite pain. This was sometimes discussed in a matter-of-fact way; sometimes it seemed to be a matter of pride. For example, one interviewee spoke about mending a carport roof despite pain. He believed that completing this task was more important than the pain it would cause. In addition, many respondents spoke about not prioritising pain over hobbies or activities that were highly prized (e.g., cake decorating, gardening). Working to earn a wage to support their family was also often prioritised over experiencing pain. But [pain] hasn’t stopped me playing sport. It hasn’t stopped my work. It hasn’t stopped social interaction or anything like that. [#24, male, back pain] I love gardening so I just do it anyway whether I have pain or not. [#424, female, shoulder & hip pain] Despite claims that pain did not rule the lives of these participants, pain did have some effects. (For example, see the quote above from respondent #497). These effects seemed to be far reaching; affecting home life, work life and relationships. For example, one interviewee (#305) claimed that she had lost trust in people as a result of her pain experience; that she could not rely on others to treat her Chapter 7: Phase 3 – Semi-structured Interviews 210 well. Interviewees appeared to be engaged in a constant juggle to maintain a balance between achieving sufficient quality of life and minimising pain. When I do things that, perhaps I regret having done; [pain] will get particularly bad; when I just need to manage it with painkillers and resting. Yes so that’s basically it. There are things I can’t do such as mowing. I’ll get a mower man in to mow. I can do it. But I would regret it the next day. I would not be able to do the things that I’d like to do the next day. [#497, male, back pain] Some interviewees talked about having constant reminders of the pain – a feeling, knowing it is there or awareness on another level of consciousness – whereas others spoke about deliberately ignoring or not focusing on the pain. These respondents seemed able to ignore pain successfully with often sharp reminders about their pain once the activity in which they were engaged ceased. I can be kneeling there gardening. I can be there for half an hour to an hour and the brain is elsewhere. I know what I’m doing though; it’s not that you’re not conscious of what you’re doing. I know exactly what I am doing, but I know much of my brain is somewhere else I guess. I am not even conscious of the pain until I stand up…. And I think, “I’ve been in pain down there” [#305, female, knee pain] Episodic pain “You just do what you can handle” Some interviewees described that their pain was fluctuating; either pain came and went, or, although some pain was always present, there were better and worse periods. Some people took responsibility for that fluctuation (e.g., citing that it was because they were managing their pain well). Others could not predict the fluctuations and seemed frustrated by this lack of predictability. Chapter 7: Phase 3 – Semi-structured Interviews 211 It’s just the craziest thing. Sometimes you can do it and other times you can’t [lift the arm due to pain], and there’s no rhyme or reason as to why [#424, female, shoulder pain]). For those who had some pain-free periods, these respondents spoke about continuing to do activities but changing the way that they did them to avoid pain. As one respondent put it, “don’t do things that hurt”. However, similar to those respondents who had constant pain; these interviewees prioritised some activities over the pain episode which it would trigger (e.g., team sports, gardening). Vacuuming; I now pay my son to do the vacuuming and wash the floors. Gardening; I love gardening. I have a big garden and I love it. So I have to do that in little bits at a time. 10-15 minutes at a time. If I’m doing anything that is bending then I sit down and have a rest then come back and tackle it again. [#557, female, back pain] The previous quote also illustrates that some activities were not sufficiently important to risk a pain flare-up (e.g., housework) and were delegated to others. Some activities and chores were disregarded altogether as being unimportant. Pain was viewed as another consideration in life when making small (e.g., attempting to use stairs or using the ramp) and large decisions (e.g., moving to a lowset house). In this sense, pain was often described as a hassle. Sometimes life was described as coming to a stop, for example, by spending the weekend in bed. While many respondents would recommend to other people with pain that they learn to live within their limitations, some were willing to try new treatments to manage or cure their pain and were alert to new remedies. Still others were more purposively looking for “the answer”. Chapter 7: Phase 3 – Semi-structured Interviews 212 Resolved pain “Move along and go onto something else” Some interviewees actually found it difficult to describe their pain now that it had resolved. This seemed to be more likely if the pain was not considered a large part of their life when it was present or if it was one of many health challenges that may have been superseded by other health concerns. For example, arm pain was only one of many health challenges experienced by an interviewee with a diagnosis of multiple sclerosis. Another example was sinus pain that, when compared to an earlier back pain episode, was insignificant. But I mean, you get all these aches and pains all your life, and what do you do? Move along and go onto something else. Well I do. [#119, female, resolved head pain] Finally, one respondent explained the fading memory of pain as a self preservation trick of the mind. Especially as you get older you do to tend to … forget how painful things were…. I think that when you think back it is never obviously as bad – but that is just a self-preservation kind of thing. And there are certain things in my life that I said I’m going to remember this. I’m going to remember how hard this was … Even now when I remind myself of that, I keep thinking, “It wasn’t really that bad”. [#92, female, hip & lower back pain] Interviewees gave several reasons for their recovery. Most commonly, exercise and time were cited. Another believed that seasonal changes accounted for the resolution of her pain. Suffering with the pain “It really drives me insane” Two participants described excruciating pain and significant disability and despair. These two respondents stood out from the other interviewees because of the despair and distress they described. Strikingly, there were a number of other Chapter 7: Phase 3 – Semi-structured Interviews 213 similarities between the two. Predominantly, these were their beliefs about a medical cure. They had continued to take prescription medication despite their belief that it was not helpful. Both were reliant on medical professionals to provide a cure for their pain. The level of distress and disability they experienced is highlighted in the following quote. [Pain] … progressively got worse and worse and I was on quite a few pain-killers, OxyContin, Endone, all those sort of things. It was pretty [bad]; it made me sick and all that sort of stuff. There's a time there that I couldn't even walk from my office to the factory without having to sit down with pain and when walking back from the factory to the office. It just got really, really too bad. So when they said, "Your operation is in August," it was like the best thing ever - you know … [But later] by the time I had to have the operation, I was convinced I was going to die in the operation [#819, male, back pain] Even though pain resolved for one interviewee (through surgery), this person still had significant psychological distress, which continued even though he was painfree. The other interviewee was continuing to search for a cure via a series of specialists. I am thinking maybe after 12 months I have found a correct doctor. It’s just been you know asking around everyone, everyone at work and um “you got anyone I can go to” and the guy that’s been looking after my shoulders just lately. My husband was painting his surgery and he got talking to him and he said “this is what I do. I’m a rehab doctor”. I said “yeah, that’s what I need”. But I’ve seen him now a coupla months and I’ve been going to the gym under his guidance and everything. … And um this particular doctor, this rehab doctor, has had surgery on his shoulder with this specialist. And feeling like, maybe at long last, I’m going to have some success. The Influence of Pain on Others “You snap at people when you shouldn’t” Interviewees gave many examples of how their pain had an influence on other people, mostly family members and work colleagues. Irritability was the most Chapter 7: Phase 3 – Semi-structured Interviews 214 common cause of negative effects on others. Respondents reported having to be vigilant to avoid these interactions or being alert to feedback from others. Though, some participants identified that they may not realise until after the interaction that they had displayed grumpiness or impatience. Some thought that their behaviour was reasonable or excusable given their level of pain. Some examples of social withdrawal were also discussed. For example, withdrawal from sports competitions because respondents believed that pain prevented them from performing at their peak level, which would lead them to let the team down. Also, fears of being touched by others (which exacerbated their pain), had led to social withdrawal. Coping with Pain A strong focus in the interviews was on coping with pain. The following points are the main thoughts about the best ways or the most influential aspects to managing pain – either that respondents use themselves or have observed in others. 1. Positive attitude. Respondents thought that their frame of mind was very influential in how they coped and viewed their pain. Interviewees believed that it was important to have a positive attitude and not to dwell on the hardships or difficulties of having pain. If necessary, it was central to “get on with it” rather than focusing on the pain. It was a case of mind over matter, if they wanted to achieve their goals. Now, look at my little friend up there, up the road, with her [pain] and she's so positive all the time, all the time. You know, my mother is the same age and two different people. One wants to be young and get out there, loves to be out of the house and amongst people and my mother just mopes and mopes and groans and carries on. So I think the attitude [is important] [#18, female, multiple pain sites] Chapter 7: Phase 3 – Semi-structured Interviews 215 I think its probably attitude or positiveness. … Some people tend to fall into a trap where pain becomes part of their lifestyle. So say if you know someone that’s not been well and people come up and say how you feel. People ask them how they are feeling all the time and they are not expecting a positive answer so they sort of give them the negative answer … It seems to become sort of a career. [#231, male, resolved leg pain] 2. Getting a good night’s sleep. Another aspect that some respondents spoke about was the importance of getting restful sleep. Sleep assisted respondents with the emotional and mental coping. If I can get at least 5-6 hours sleep at night, I can manage it mentally as well as physically. I find mentally I can cope. [#371, female, multiple pain sites] I think pain is worse if you’re tired. If you wake up in the morning, you probably don’t feel too bad. But if you have a big heavy day or you’ve had a lot of pain in the day, I think then, by then your tolerance is, sort of, you know. [#119, female, resolved head pain] 3. Doing things that you enjoy. Respondents spoke about staying active and continuing to do activities that they enjoyed doing. It seemed imperative to have a life outside of pain. Doing enjoyable activities could also push pain into the background for people. Well if I’m interested in what I’m doing I guess I tend to ignore the pain barrier more. But if I’m not interested in what I’m doing then I allow myself to get grumpy and decide I don’t want to do this. For instance shopping or sightseeing with my wife. [#24, male, back pain] 4. Push through the pain. Sometimes it was considered worthwhile to push through the pain. As above, pushing through the pain by remaining active could decrease the focus on pain. Pushing through the pain was also believed to strengthen the individual’s ability to bear other episodes of intense pain. From the car park to here, when I get here my calves are burning. They’re burning. By the time I sit with you here now, they’re cold. Same with the Chapter 7: Phase 3 – Semi-structured Interviews 216 thighs. They burn hot. Pain. But I push through that because I learnt how to push through the back pain. [#406, male, back & leg pain] Gatchel’s Model A main research aim of this phase was to examine the premises of Gatchel’s Model in relation to participants’ experience of pain. Some of the key premises of Gatchel’s Model include 1) pain leads to inactivity which leads to dysfunctional behaviour patterns, 2) the resultant psychopathology is influenced by individual characteristics and environmental factors, and 3) mental and physical deconditioning processes are interactive. Like all the data presented here, these premises are addressed separately for the purposes of clarity, although as the concepts in Gatchel’s Model are interconnected, so too were the ways in which participants spoke about these themes. The Disability Sequence: Pain, Inactivity, Dysfunction The main premise of Gatchel’s Model, upon which many of the other assertions rest, is that pain leads to inactivity and the greater the duration of inactivity, the greater the likelihood of developing dysfunctional behaviour patterns including physical de-conditioning (disability). However, as mentioned previously, the premise that pain leads to inactivity was inconsistent with the reports of most interviewees, particularly those with constant pain. Specifically, interviewees spoke about remaining active despite pain. Interviewees cited a number of strategies that were important to enable them to remain active. These strategies included changing how they undertook tasks, making additional preparations prior to commencing a task, seeking help, going slower, not measuring themselves against others, being realistic about what they Chapter 7: Phase 3 – Semi-structured Interviews 217 could achieve and doing activities that they enjoyed or were otherwise worthwhile for them. Determination was often cited as a key ingredient necessary to achieve and stay active. Some people spoke about giving up certain activities that were unattainable (e.g., bush walking) but committing to other more attainable and still enjoyable activities (e.g., walking and cycling). The pain experience seemed to have changed the behaviour of the majority of participants but the changes were reported as functional changes that allowed continued activity and quality of life. Actually that’s a thing [driving] that I have really restricted, even in my own vehicle because it aggravates me. I think when I first realised it was when I was driving [buses]. … And that’s when I fortunately I was able to make careers changes to help me deal with that. … So what I’ve got to now is I’m in an admin job and I do find the seats better designed and help me a lot. So I’m not bouncing up and down in vehicle for example. So change of lifestyle. [#497, male, low back pain] There were a number of reasons that interviewees spontaneously gave for staying active. Some people used activity as a distraction tool for pain (e.g., walking to the local shops when their hand was sore). Others remained active or exercised for the mental health benefits. It's interesting because I can get up feeling really horrible on a day that I am due to go to the gym and I make myself go. The very fact of doing that physical exercise makes the improvement. So if I can get myself out of bed and get going, go and do it, I'm fine. I feel better when I walk out, you know, an hour later, and the improvement continues for the rest of the day. [#215, female, shoulder pain] Some interviewees received advice from health professionals, specialists and physiotherapists that they should remain active and exercise. Although a few respondents spoke about stopping some activities and responsibilities (e.g., gardening), they resumed doing these activities out of necessity. Chapter 7: Phase 3 – Semi-structured Interviews 218 Respondents spoke about a use it or lose it attitude. This was true even if physical activity caused or increased their pain. Some participants also kept exercising despite health professionals’ warning that this particular exercise may increase the damage at the injury site. These risks seemed to be outweighed by other benefits. Reasons given for continuing these types of exercise included enjoying that type of exercise, weight maintenance and established family time. I look at exercise as it’s going to keep me walking. He said no walking, no push bike riding, no climbing. … I love walking. And I tried the exercise to decrease the pain. It doesn’t. It increases the pain. … [The specialist] said that you have to rest it. You cannot walk. The more I use the joint, the more I split the joint. I give him that. But again it comes back to, he said don’t, but I have to. So long as I keep moving hey it’s got to be good. [#305, female, knee pain] In summary there was little evidence for the premise that inactivity and disability would result from the experience of even constant pain; the majority of the interviewees described continuing to be active despite pain. Primarily this seemed to be because these activities were considered worthwhile by respondents. However, some activities may have increased participants’ current and future pain. Underlying some of these decisions appeared to be an absence of fear of pain. Mental De-conditioning: Struggling to Cope Gatchel’s Model also posits that there is a positive relationship between pain duration and mental de-conditioning (similar to that with physical de-conditioning). As discussed earlier, according to Gatchel’s Model, the development of psychopathology is dependent on individuals’ characteristics and environmental factors. It also hypotheses that individuals will become mentally fatigued by failed attempts to relieve pain. Chapter 7: Phase 3 – Semi-structured Interviews 219 Influence of Emotion: “Emotions do play a part for me” While pain duration was not raised as an important construct by interviewees, participants recognised the influence of emotions on their pain. Respondents identified that, for them, pain could lead to worse emotional states such as irritability, impatience, and anger (see earlier section on page 213). Some believed that that the relationship was unidirectional, where pain led to irritability, for example, but positive mood states did not relieve pain. See, today it is great; it really is. … I don’t think it’s because I’m happy at the moment. I just think that I didn’t do anything to annoy [my back]. [#557, female, low back pain] Others believed that the relationship between emotional state and pain experience was bidirectional. Some interviewees spoke about this relationship in a specific sense, e.g., on a pleasant occasion pain was decreased because one was enjoying themselves. Others presented this relationship in a more global sense. … if you get a really nervous uptight person who always got something wrong with them and dying of something, I think their emotions probably make their pain appear worse. [#119, female, resolved head pain] But emotions do play a part for me in … if I am worried and nervous and stressed about something, I find that I’m in more pain. … And to me that is all a part. If you are stressed and worried about something, then you’re not sleeping, then your body is not rejuvenating. And so when your body is not rejuvenating, then something has got to give. [#371, female, multiple pain sites] Interviewees identified a cyclic nature to the relationship between mental states and pain. Coping with pain was easier on some days compared to others. I must admit that some days I’ve just sat down and cried because it’s all got too much. I can’t deal with this any more. … But the next day I was alright. But most of the time you just get up and keep going. [#371, female, multiple pain sites] Chapter 7: Phase 3 – Semi-structured Interviews 220 If you are down for the day, if you are feeling down, something has happened and you are down, I think everything else feels down, too. Everything is flaring up. Even though it's no worse than yesterday, it flares up in your mind because you’re down. [#18, female, multiple pain sites] Influence of Personal Characteristics: ‘I’m a pretty resilient person” While interviewees did not spontaneously introduce mental illness into the conversation, personality aspects were considered important in how they managed their pain experience. Interviewees cited independence, determination and resilience as being important characteristics which they held and helped them cope with pain. I am an independent cuss, so I don't want to have people doing things for me or anything like that unless I really need their help, whereas other people are more dependent, I think, and they sometimes use that as a way to make contact with people or … I don't know. [#215, female, shoulder pain] A related aspect that was discussed by a small number of participants was their experiences with illness in childhood or young adulthood. These respondents stated that these previous illness or pain experiences had given them the skills to cope with their current pain. Everything I experience now, I compare to that renal colic pain. I have never experienced anything as bad as that renal colic pain. So it’s like you say to yourself, “it is not as bad”. [#305, female, knee pain] I have a very strong threshold to pain. I tell myself that and I always have as a child. I think because of the operations I had to endure all the time, much time I was in hospital for the ears and throat. [#18, female, multiple sites] Chapter 7: Phase 3 – Semi-structured Interviews 221 Attitude: “Woe is me” Some interviewees identified extended family members who were not coping with their pain. Many respondents put this down to attitude and the way that these people thought about their experience. She tells her mind that, "Woe is me, my pain," and nobody else in the world has any pain except for her and she's a real drama Queen, she really is, … I just say, "Well, look, maybe if you move it more, it will be better," sort of encourage her. She is the opposite [to me]. She will have a handful of tablets, "They don't work; they don't work." And her attitude is very negative, very negative [#18, female, multiple sites] I suppose I am a little bit more determined because I have a sister-in-law that is just [shakes head] …believe me. And I keep thinking, my God, just get up and get on with your life. Get over it. It’s not that bad. … And I suppose I gauge myself on that. [Interviewer: Is your sister-in-law getting better?] No. She’s got herself on a walker at the age of 46, which is, you know [crazy]. [Interviewer: Do you compare her with yourself?] I’m not a malingerer. I tend not to be and I don’t think I am. But she is a totally different person, … It doesn’t matter how bad somebody else is, she has got herself into this stage now, that she is the worst and nobody can make it better. Even though doctors have said, for God’s sake get on with your life. Stop doing this to yourself. It depends on the person you are. And I think a lot of it has to do with … her and I and our situation, our background is a lot of it. She comes from … her family is a bit that way, o woe is me, close the windows, close the doors, don’t let anybody in, I’ve got to stay inside - whereas my family has never been like that. … And the willingness to help yourself; really to me that is a lot of it. Just to deal with it and try and make yourself better rather than accept that I’m in pain so I’ll go to bed. I’ve got clients who have done that. They can’t deal with it so they go to bed and that’s where they stay and that’s where they die. But she is a lot younger than I am. I get frustrated. [#371, female, multiple pain sites] Chapter 7: Phase 3 – Semi-structured Interviews 222 Exhaustion: “It still wears you out a bit” Consistent with Gatchel’s Model, interviewees described pain as exhausting. Specifically, pain was described as capable of wearing down one’s resources and that this effect could be exacerbated by sleep disturbance as a result of pain. The below quotes provide some examples. It makes me a bit tired sometimes. It does wear you out. Pain does wear you down a bit especially when you’re trying to do things that you need to do. And you’re trying to ignore it; it still wears you out a bit. [#497, male, back pain] But it’s when you’re woken up at 2 o’clock in the morning and you can’t go back because your shoulder is aching. And you think, ohhh, and I lie there holding it. And I’ll put the heat pack on and I’ll take some tablets and think, “just stop; just let me get some sleep”. [#371, female, multiple pain sites] Evidence of Mental De-conditioning: “Is everything going to be all right” While the above descriptions are representative of the majority of the interviewees, there were two interviewees whose experience was quite different (see earlier section of page 212). Recall the experience of one of the men with low back pain. He had experienced some psychopathology in terms of depression and anxiety with his low back pain; this is consistent with Gatchel’s Model. After surgery had corrected his injury relieving his pain, he continued to experience depression. He also began to have panic attacks, for which he was under the care of a psychologist. Using Gatchel’s Model as a framework, this individual would not have been expected to continue to have problematic psychological symptoms or the development of new symptoms. However, this may be explained by a predisposition to depressive and anxiety disorders, which may fit with Gatchel’s Model. Chapter 7: Phase 3 – Semi-structured Interviews 223 Summary of the Disability Sequence. In summary, emotions (i.e., mental de-conditioning) were described as being related to one’s pain experience by the majority of interviewees. Pain duration did not factor in this relationship though. Respondents described background factors that were protective (such as determination) rather than risk factors for poorer outcomes. Despite the exhausting nature of pain, some people found the strength to keep going and keep active. Being worn down by pain was a temporary affliction rather than one which lead to increased disability. Crossover between Mental and Physical De-conditioning: “Exercise gives you a dose of euphoria as well” Gatchel's Model proposed that mental and physical de-conditioning processes are not independent, but rather, these processes influence each other. In the interviews, there was evidence of links between mental and physical deconditioning. Participants spoke about exercising even when they did not feel like it for the mental health benefits (see also quote from #215 on page 217). For me exercise doesn’t help, um, physically. But mentally yes. It is a huge buzz mentally. That I can go walking for 4kms, 5kms, um, and it might sound big-headed but I come home and I feel really proud. [#305, female, knee pain] Protective Variables The interviews provided an opportunity to examine the protective variables (identified through the literature and examined in Phases 1 and 2). These variables included coping strategies, optimism, self efficacy to manage pain, beliefs about pain and pain management, social support, and positive affect. These same variables were examined to the extent that they occurred in the interview data. Chapter 7: Phase 3 – Semi-structured Interviews 224 Coping Strategies Many of the coping strategies that interviewees spontaneously spoke about using are those strategies that are assessed in standardised questionnaires. While these strategies are judged by health professionals to be helpful (or not) for long term pain management, this data provided an insight into how people with pain viewed these strategies. Typically, interviewees viewed coping as a personal phenomenon where different strategies worked for different people. I think everybody has got their own way of dealing with pain and we have all got our own cures and remedies [#559, female, resolved back pain] Self-talk and distraction: “Using our computer disk”. The importance of attitude and using cognitive skills to cope with pain was emphasised by interviewees. Participants spoke about using self talk to “call themselves to task” or motivate oneself to continue a task despite pain. Often participants acted as the devil’s advocate and used insults to motivate or as punishment for not taking appropriate preventative action. Self talk was also used to soothe and comfort oneself. Apart from being a little bit self-abusive and saying “you stupid *** - you should have been doing this days ago” – when you first got twinges or whatever. That’s bout the only thing that is consciously going through. [#156, male, knee/ shoulder pain] I actually do talk to myself and go, "Oh, you are just being stupid. You are just being an idiot. Get up and start moving again," [#18, female, multiple pain sites] It might sound funny. But I talk to myself. That’s my coping mechanism. “Just calm down. It’s not that bad. It’s going to stop in a minute”. [#371, female, multiple pain sites] Chapter 7: Phase 3 – Semi-structured Interviews 225 Distraction was used to give oneself a break from the pain. Participants used tasks at work and at home as a distraction from pain (see earlier section on page 210). Cognitive abilities were also used to “switch off” from pain mentally. Sometimes switching off sounded like an automatic process but other participants did this more intentionally. I just take myself into another zone; the body is doing one thing but the mind is just not there. [#305, female, knee pain] So generally I manage it, by concentrating on other things for a start. I’ve got lots of things to do. And I often think “it’s not worth concentrating on that, let’s concentrate on that. What do I need to do? What’s more important?” [#497, male, back pain] For some interviewees, distraction was all they used or all that was required to cope. For others, it was the only coping mechanism that the situation allowed or the first step in a line of coping strategies that may be used. Distraction was also used in combination with other strategies such as medication or rest. So for example, if I need to do something and I have got bad pain, I will just deal with it by painkillers and concentrating on what I need to do. Sometimes … it might make it a bit worse later on but at least I’ve done what I needed to do or wanted to do. [#497, male, back pain] Using distraction to cope with pain may have other mental health benefits. Being able to ignore pain in order to attain a goal was described as very rewarding. Interviewees spoke with pride about what they had achieved despite pain (see above quote from #497). Distraction was also used to cope with the emotional consequences of pain. I change my thought pattern, sort of thing. So as soon as you feel yourself getting a bit too depressed, you try and think of something else, sort of thing. [#819, male, back pain] Chapter 7: Phase 3 – Semi-structured Interviews 226 Rest and relaxation: “Pull back, relax, and just let it go for a minute”. Rest was used particularly by interviewees with low back pain. Rest was mostly described as a short term coping mechanism, which was used as a specific strategy in relation to a specific incident. Resting was not described as being used to prevent pain. Periods of rest were followed by resuming normal activities. In addition, if rest was not possible due to environmental constraints, most typically being in the workplace, then other coping strategies were used. So most times I try and concentrate on what I am doing but if it gets really bad, some bed rest. And bed rest is usually only, take some painkillers, strong painkillers, and rest for perhaps an hour. Then usually it’s get up and continue on with what I need to do. [#497, male, back pain] Getting help: “I try to get assistance more than anything” Few respondents spoke about asking for assistance with tasks as a coping mechanism. Although, as mentioned in earlier section on page 211, some tasks were relegated to others. These were typically household tasks such as carrying groceries, mowing and house cleaning. I have found lately – and it’s just been over the last few months – that the kids come shopping with me now; just getting the groceries into the car and out of the car and upstairs. [#371, female, multiple pain sites] Exercising: “I just do my exercises and it goes away”. There were a range of opinions about completing exercise generally and exercise in particular to cope with pain. For some participants, exercise in general in terms of keeping active had benefits for managing their pain. Additionally, it also had positive effects on their mood, e.g., “exercise gives you a dose of euphoria as Chapter 7: Phase 3 – Semi-structured Interviews 227 well” [#231, male, resolved leg pain]. Some interviewees had specific exercises to keep pain at bay or to ease pain once a new episode or flare up had begun. Many of these exercises were recommended by a physiotherapist or chiropractor. Other participants had a negative opinion of exercise and despite recognising the benefits of the specific physiotherapy treatment regimes, resented having to adhere to these regimes. See the below quotes for an illustration of these ideas. I also have twinges when I’ve just turned [in my seat]. I think it’s probably just a joint gets locked or something. And that is really painful and I can barely move. And the way to fix that is to stretch my spine – either hang off a beam, or lie on the floor and get someone to pull on my legs. And almost immediately, I’m ok. [#24, male, back pain] I think I’ve had enough of physiotherapists, you know. And that is probably a bad thought, because they are good at what they do. They do provide good exercises. But they also have a different focus on life to me. Their focus in that you exercise every day. I have never exercised in my life. I’m not that sort of person. So doing this was foreign to me, particularly with my arms, the exercises for my arms. But otherwise I am then down to limited mobility and pain. I don’t want either. [#283, female, hand & shoulder pain] Potentially an important part of exercising is also one’s attitude to exercise and keeping active. Some people did not have an exercise regime per se but nonetheless they remained active. I do a lot of walking day-to-day and a lot of exercising. I don’t exercise as in people walking up and down the street. My doctor says I should but I don’t because I figure I do enough. [#371, female, multiple pain sites] Optimism and Positive Affect: “Mind over matter” As previously mentioned on pages 214, interviewees believed remaining positive, even during pain flare ups, contributed to their psychological well-being Chapter 7: Phase 3 – Semi-structured Interviews 228 and how well they coped with their pain. Respondents generally believed that they had always been “positive people”. The possible influence of a positive attitude was captured by one participant when they spoke about the people that they knew who had been diagnosed with serious illness (e.g., cancer, multiple sclerosis) and, in her mind, had given up and therefore died shortly afterwards. I think attitude has a lot to do with pain and I think your attitude towards pain means you either have a good experience with it or a bad. So I value life. I have still got lots of things to do, so whatever happens I will kind of deal with it as it comes along, hopefully. [#559, female, resolved back pain] One participant spoke about not moaning or whinging because of the negative influence it has on your experiences. In the interview, even though she could list examples of physical limitations that pain imposed, cognitively these were downplayed. She said that her pain “hadn’t really affected” her activity levels. Other interviewees also spoke about being active rather than sitting at home and feeling sorry for themselves or that being miserable was not helpful. I think you’re better if you’re up and about and going to work than if you’re at home, thinking “I’m so sick, I’m so miserable, I have to lie down and go to bed”. [#119, female, resolved head pain] But for me it is mind over matter, nobody’s going to tell me I can’t do anything. So the longer I stay active, the longer I can be active. I am 57 and I am not in a wheelchair. I have no intention of being in wheelchair. … I am not going to stop. I am not going to be one of these people who is waiting to die. You come through here once and I intend to live life. [#305, female, knee pain] Further, despite a significant pain condition, participants actually “counted their blessings”. Some interviewees did this by comparing themselves to those worse than themselves. You need to say, yes I am in pain but I can still do this, I can still do that, I can still move. You aren’t crippled, lost and unable to do things for yourself. Try Chapter 7: Phase 3 – Semi-structured Interviews 229 and look at it that way. And think about the people that are out there and are a hundred times worse off than you. I had an aunt whose fingers were so bent she couldn’t even feed herself. [#371, female, multiple pain sites] Some people whose pain had resolved through treatment viewed their (optimistic) attitude that they would find a resolution as a strength that had encouraged them to keep seeking treatment. Eventually these two participants had found pain resolution; one through shoe inserts and the other via physiotherapy treatment. Because their searching lead to successful treatment it is difficult to know how fruitless searching may have affected their experience. However, both had remained active despite pain during this period. This may act as a safeguard against disuse syndromes like those described by Gatchel’s Model. Self efficacy to Manage Pain: “Pain doesn’t stop me” Participants spoke about self efficacy in terms of a range of behaviour, including managing pain, finding ways of easing pain, seeking pain resolution and finding information. Participants believed self efficacy to manage pain is innate. Determination was an important component of this. Participants believed that they had the knowledge or the skills to manage the pain during a flare up. Many believed that they could predict a flare up and therefore take preventative action or could actively manage this flare up. I’m confident that I can predict in advance that this is not going to be nice to my back. [Back pain] really hasn’t stopped me doing things. And it won’t! [#24, male, back pain] In addition, interviewees mostly disagreed with the item, there is little that I can do to ease my pain. They seemed to take responsibility for either finding a cure Chapter 7: Phase 3 – Semi-structured Interviews 230 or easing their pain, saying that there was always something, even if it was small, that they could do. [Pain is] something that you have and you can either do something about it or you can sit around and moan. I'm not a ‘sit around and moaner’ type. So I will do something about it. [#559, female, resolved back pain] As I said, there's little you can do, but there's always something you can do. … I just sit there if I am watching telly, I will just gently manipulate [my finger] like that and just rub it gently and pulling it back, like so. … With my neck and back problem, I find by using the backpack handbag 100% better than having a handbag on your shoulder. [#18, female, multiple sites] One participant agreed with the statement, there is little that I can do to ease my pain. She stated that she had tried everything to no avail. However, when pressed, she did receive a few days relief from cortisone injections. She identified herself as a resilient person; she was unable to get relief but did not let the pain affect her life. For me that would probably be true. I’ve tried everything. I even tried the bean bags in the microwave, the heat, thinking that if I make it so boiling hot the all I could feel is the pain of the heat. Or even … Inflicting pain on some other part of the body so all you can feel is this pain; you can’t feel that [pain] any more. Even resorted to doing that. It works. Or getting someone else to do it. [#424, female, shoulder & hip pain] Beliefs about Pain and Pain Management A number of beliefs about pain were expressed explicitly or implicitly by participants. The topic that interviewees spoke the most about was medication use and use of other medical services. Other beliefs that were discussed in the interviews focused on social support and the responses of significant others. Chapter 7: Phase 3 – Semi-structured Interviews 231 “I don’t take pills or anything like that”. Opinions about the use of medication were wide ranging. While some interviewees were against the use of pain medication, many respondents talked about pain medication for severe pain only or as a last resort. If they did not take pain medication, often they stated that their pain was not severe enough to warrant this intervention. Other participants used pain medication during flare ups or used a medication hierarchy where over-the-counter medications were used regularly and prescription medication was used only during pain flare ups. I’m not one of these to take anything for pain unless it’s really bad. And yes, if it’s really bad I will take it. [#119, female, resolved head pain] Not with medication. I’ve already decided that when it gets to the stage and I can’t handle it, I will go and try acupuncture, that sort of thing. [#305, female, knee pain] When it gets really bad I, it does respond in my case to some anti-inflammatory, and I take Proxin or whatever for 3 or 4 days just to ease it down and then I knock it off. [#156, male, knee & shoulder pain] The notion of a pill popper was a negative image for most interviewees. Many participants said that they were not that sort of person, implying that medication use is confined to a certain type of person. In addition, participants said that they did not like to take medication. Some cited that medication was just a bandaid-type solution that covered up the problem but did not resolve it. I would dearly love, I mean if there was something I could swallow to be long life pain-free, I would pay for it. It wouldn’t worry me. It would be just great. But you’re just working with pain killers. That’s all you’re doing; they’re not actually fixing. It’s just a bandaid. [#557, female, back pain] Finally, interviewees commented on the side effects of medication – commonly constipation and occasionally the tolerance effects. Chapter 7: Phase 3 – Semi-structured Interviews 232 “If it gets bad, I’ll see a doctor”. Most respondents had disengaged with the medical system with the exception of the two interviewees who were struggling to cope (see earlier section on page 212-213) and one participant who was receiving quarterly spinal injections. The other interviewees were self managers of their pain. In fact, some specifically said, they wanted to avoid specialists as long as they could. I suppose I should go back and get it re-assessed. And just see what they say now. Spend 100 dollars or so, because I’m in private cover, and just see what they say. Could be worth it. Must be 20 years since I’ve had it looked at. [#557, female, back pain] Several references were made about doctors being incompetent or misdiagnosing the cause of their pain. One respondent spoke about being put in plaster from neck to knee to cure back pain. Another spoke about botched surgery at the hands of an orthopaedic surgeon (confirmed by two other specialists). There is no one else to go to. I have exhausted the medical profession. And they don’t know anything, today. They know very little. [#406, male, back & leg pain] On the other hand, participant #424, who struggled with pain, had received many diagnostic procedures and had seen numerous allied health professionals and medical specialists. Her experience is reminiscent of those described by clinical patients. I’m also having an MRI because I’ve had everything. Same with the hip. Every ultrasound, every x-ray, every drug. Um, physio, acupuncture, chiropractor. You name it, I’ve had it. But still can’t pinpoint what actually it is. [#424, female, shoulder & hip pain] Chapter 7: Phase 3 – Semi-structured Interviews 233 Social Support and Solicitude Beliefs Interviewees had few expectations of support. Correspondingly, less than a third of the interviewees spoke about the social support they received or did not receive. “Whinging and moaning”. In terms of respondents’ beliefs about solicitude, some participants saw their pain as a private experience and therefore did not want to “sit around and moan” about their pain. Others believed that a little bit of whinging was reasonable and that it was acceptable to indulge in a bit of whinging every now and then. There's no point saying to somebody … if I say to you, "I've got arthritis in that finger." You have a look and say to me, "Oh, poor thing, how does that feel?" You can't feel that pain, so you don't understand what I am saying. So what's the point? No-one likes to know. [#18, female, multiple sites] Who wants to go complaining about [pain] all the time when you want to do other things with people? If you go out doing other things with people, you don’t always say “ohh, I’ve got bad back pain; don’t know why I’m here” and that sort of rubbish. [#497, male, back pain] Oh, I might whinge a bit occasionally. If you have got someone with you and [the knees] may hurt, and you whinge a bit but that's all right. [#355, male, knee pain] However, too much assistance or sympathy as a result of whinging was seen as negative. Some interviewees believed that too much assistance or sympathy may encourage a person with pain to do less; many respondents cited examples of people who used their pain and the associated support received to avoid tasks and gain attention. Some believed overly supportive behaviour could contribute to the continuation of pain. Chapter 7: Phase 3 – Semi-structured Interviews 234 “I have a fantastic partner”. A few of the women talked positively about the support that their husbands offered them. Just the fact of saying this appeared to have a calming affect in these participants. This was not the case for all respondents, e.g., one woman said that her husband would not even know if she was in pain. A few respondents spoke about raising their pain with their partner as pointless because their partner was not able to “do anything” about the pain. “Using a support group”. One respondent who had experience severe low back pain that was eased with successful back surgery believed that support-style groups where people with pain and people who had surgery could offer support to each other. He believed that this was a service that the medical profession should organise and offer people waiting for surgery. As discussed in previous sections, this participant’s experience and viewpoint was not widely held. Revisiting and Understanding the Questionnaire Data The collection of qualitative data provided some insight into the results of the quantitative phases. As noted previously, this is a strength of a mixed-methods approach and was one of the aims of this phase. Categorising Respondents’ Pain Experience Some of the respondents, who had been categorised as having chronic pain at baseline that had resolved at follow-up, upon closer examination during the interview still had episodes of pain. Of the eight interviewees who had been Chapter 7: Phase 3 – Semi-structured Interviews 235 classified as resolved chronic pain, four had ongoing pain episodes at their nominated pain site and one had the potential for additional pain episodes (although this was minimised through good pain management). The pain of these respondents appeared to be better understood as episodic pain; by chance they were experiencing a pain-free episode during the follow-up data collection. Regardless, it is difficult to categorise people’s experience with pain. This was evident when considering participant #559. Although, she was classified as having resolved acute pain, which seemed to be an accurate reflection of her lower back pain, this participant had extensive experience with continuing arthritis pain (a chronic pain condition). Survey of Pain Attitude (SOPA) Items Three items from the Survey of Pain Attitudes (Jensen et al., 1994) (Jensen et al., 2003) (refer to Chapter 3: Methodology) were discussed with interviewees. These items were explored in the interviews for two reasons: to allow aspects of the pain experience to be raised with participants without the inference that the interviewer held a particular view, and to enable the thinking behind and reasons for the responses to these questionnaire items to be explored. Items were chosen as examples from the subscales with poor internal reliability (see Chapter 4). Discussion of statement 1, “there is little I can do to ease my pain”, revealed that participants had interpreted that item a number of ways. Some people talked about a short-term focus, whether they could ease their pain today, versus a long-term focus, whether their pain could be cured. For a single individual then, this item may have been interpreted in two ways as per the quotes below. Chapter 7: Phase 3 – Semi-structured Interviews 236 If you look at it "ease my pain", yeah, if I sit down, I am going to ease my pain, or if I lie down I am going to ease my pain. But the fact that my pain is going to be here today and it's going to be there tomorrow and it's going to be there tomorrow after, in that sort of sense, yeah, my pain is not going to reduce. It's not going to get any better. [#819, male, back pain] I’ve got a left hand and a right hand response to that. If I say I’d agreed with that, I wouldn’t want it to be seen that as losing hope; that I’ve given up … But on the other hand, if I say there isn’t much I can do to ease my pain because I live with and I get on with it anyway. I see that as a more positive response, giving the same answer to that question. [#24, male, back pain] Given that health professionals would view disagreement with this statement as a more adaptive response; reliance on this item may be misclassifying people’s attitudes and resultant behaviour. The second statement, “there's a connection between my emotions and my pain level” received little support in the Phase 1 data collection (see Chapter 4 for the results of the SOPA emotion subscale)33. However, when discussed in the interviews, most participants agreed with this statement. One explanation for this discrepancy is that participants had not considered the influence of emotion prior to reading this statement on the first questionnaire. Once they were exposed to this idea, they may have noted the influence of emotion on their pain in the following time period. Alternately, when reading that item on a lengthy questionnaire, participants may not have considered the item as deeply as they did when asked it in conversation, such as only thinking about if emotion affects pain rather than including instances where their pain increased emotion (like irritability), which was a common response in the interviews. The inclusion of the third statement, “exercise can decrease the amount of pain I experience”, highlighted that some respondents may be doing exercise that is 33 Of the 20 interviewees, 14 nominated that this statement was not true or did not apply to them. Chapter 7: Phase 3 – Semi-structured Interviews 237 contraindicated for their type of pain. Nonetheless, most remained active and had a positive attitude toward exercise. Discussion Phase 3 further explored the experience of pain in a more detailed way and investigated the processes of Gatchel’s Model from the viewpoint of people with pain. The data collected in this study lead to a re-evaluation of the Phase 1 and 2 data through a better understanding of how participants’ interpreted the questionnaire items and the episodic nature of some of their pain conditions. As a result, a richer picture of the nature of pain was obtained. The Experience of Pain There were a number of ways that pain was viewed by interviewees from battling with pain to co-existing with pain. One’s view of pain obviously influenced each person’s experience of pain and the way that they attempted to cope with their pain. Regardless, the majority reported coping sufficiently well with their pain. In addition, most participants would be considered to meet the goals of health professionals working in the area of pain, that is, participants were functioning despite pain. Similar to other cognitive processes that are believed to affect decisions about health, (e.g., health belief model), participants seemed to weigh up the costs and benefits of continuing to be active despite pain. Moreover, many interviewees seemed to detail with pride the roles that they continued to have despite pain. As role loss is associated with poorer psychological adjustment (i.e., depression) (Harris, Morley, & Barton, 2003), the fact that participants involved in Chapter 7: Phase 3 – Semi-structured Interviews 238 this research phase reported little change in roles (or conversely, much stability in their roles) may provide an explanation for why they reported coping so well. Pain had an overwhelming influence on the lives of the interviewees and affected all facets of their lives. However, overall the impression that the author had was that these respondents were characterised by flexibility about how they managed their pain. The level of importance attached to the functional changes that they made to cope with pain was consistent with how well respondents coped with the experience of pain; participants who did not attach much significance to their pain condition and the changes that it necessitated appeared to cope most well. This may fit with research that shows that the greater the influence of pain on chronic pain sufferers’ perceptions of their “self” and their future hopes and dreams, the worse their current level of coping (Morley et al., 2005; Sutherland & Morley). Cognitively down playing their own experience of pain may have protected these respondents’ sense of self, which was not reliant on being pain-free. This mismatch between the severity of pain and disability with respondents’ report of wellness or well being has been found in other quantitative research. Söderberg reported that, “The results produced a complex picture of women with FM [fibromyalgia]. On the one hand, they reported severe pain of different kinds, concentration difficulties, and fatigue. On the other hand, they rated themselves as feeling quite well and ‘like others’.” (Söderberg, Lundman, & Norberg, 1997, p. p501). Although many participants spoke about accepting their pain as part of their life and making the necessary changes to remain functionally active, still they spoke about becoming annoyed and frustrated with their pain or related disability at times. Participants also spoke about living despite pain, accepting that pain was a part of their life and making adjustments for pain to continue to have a meaningful or Chapter 7: Phase 3 – Semi-structured Interviews 239 rewarding life. Regardless, the total experience of pain appeared to be acknowledged by these interviewees (e.g., reporting that they also had “miserable” periods). Nonetheless, for the majority of the time, these participants prioritised other activities or events over pain (e.g., seeing the sights whilst overseas for work, working for a living). Living despite pain with all that entails sounds very much like pain acceptance (McCracken, 1998; McCracken & Eccleston, 2003, 2005, 2006) which is a current concept in pain literature but which has proved difficult to capture quantitatively (McCracken, Vowles, & Eccleston, 2004; Nicholas & Asghari, 2006). As noted previously, this is like that which health professionals would like to see pain patients integrate into their lives. The experience of two participants was not consistent with the majority. These participants described experiencing extreme distress and disability. Unlike the other interviewees, these participants had sought (or were still seeking) a cure through medical specialists and had undergone many diagnostic tests. One participant continued to experience psychological disorders after he was pain-free. When considering some of the risk factors for continued pain and high levels of disability (see Chapter 2), interviewees did not exhibit catastrophising cognitions, with the exception of the two extremely distressed participants. Respondents seemed able to disengage from cognitions about pain as a threat, which would be associated with fear-avoidance beliefs, for example by ignoring pain or using other distraction techniques. Fear-avoidance beliefs are also associated with withdrawing from activities that cause pain, which was clearly not the case for most participants. Consistently, participants reported having a positive attitude, getting rest, doing enjoyable activities and pushing through pain if necessary were key to coping well with pain. Chapter 7: Phase 3 – Semi-structured Interviews 240 Gatchel’s Model Interviewees’ point of view about their pain and their description of their pain experience offered some support for Gatchel’s Model. The experience of two participants who described much distress and disability fit with the predictions of the Model most closely. Although, as noted previously, the psychological distress of one participant did not resolve with his pain; this was inconsistent with the predictions of Gatchel’s Model. For most interviewees, pain had not resulted in inactivity and disability. This is in clear opposition to that which would be predicted by Gatchel’s Model. While remaining active required specific strategies in order to be achieved, it was clearly possible for these respondents. The attitudes of these participants to exercise may have encouraged them to remain active despite pain and also complete specific rehabilitative exercises provided by physiotherapists and other allied health professionals. Again there seemed little evidence of the development of mental deconditioning. However, the manifestation of mental de-conditioning is dependent on individual characteristics and environmental factors. Because of the variety of factors and influences that may affect the presentation of mental de-conditioning, this is a challenging concept to assess. The influence of emotions on the experience of pain was reported by many participants, which is partially consistent with the premises of Gatchel’s Model. The report that irritability was a common emotion was consistent with the data from Phase 1 where one-third of the sample endorsed that their pain made them more irritable. Several participants, however, strongly rejected any notion that their pain had any non-physiological components. Rather than psychological vulnerabilities, participants cited personal strengths such as Chapter 7: Phase 3 – Semi-structured Interviews 241 determination and resilience which helped them cope (and presumably prevented deconditioning syndromes). When speaking about other people with pain, respondents cited that dwelling on their pain and having others assist the person with pain to ruminate on their discomfort were vulnerabilities. Consistent with Gatchel’s Model, interviewees reported that pain wore down their resources and could affect their ability to sleep (further wearing down their resources). This may explain the cyclic nature of their emotional state where coping on some days was very difficult. However, many interviewees knew how to relieve or reduce pain, even if just for a short period. Being able to relieve pain at times may have contributed to the inconsistencies of these interviewees’ experiences compared to what would have been predicted on the basis of Gatchel’s Model. True to Gatchel’s Model, interviewees spoke about the interaction between physical activity and psychological well-being, although this was discussed in a positive context (i.e., that being active could increase mental well-being). Spontaneously, interviewees spoke about a number of the protective factors that are of interest in this research. Of the coping strategies targeted in clinical samples, respondents in this community sample found distraction and self-talk, and exercise useful. Asking for assistance and expecting solicitous responses from others was mentioned less frequently. As these types of beliefs have been associated with greater psychological dysfunction in clinical samples (Jensen et al., 1994) it is perhaps not surprising that it was infrequently raised by these respondents who reported coping well with their pain. Remaining positive and having a positive outlook was deemed imperative by these interviewees. This attitude appeared to bolster respondents when coping was difficult. Some respondents believed that a positive attitude also had health benefits. Chapter 7: Phase 3 – Semi-structured Interviews 242 Tied in with positive attitude was self efficacy to manage pain. Being determined and having the knowledge and skills (and the expertise borne of long-term pain) to manage a pain flare-up and pain on a day-to-day basis were key elements in managing pain. Even for the respondents whose pain had resolved, these respondents reported that a strong belief that they could find a cure for their pain was crucial in their search. As this is a retrospective account, it is difficult to assess whether these respondents would have rated their self efficacy as strong while they were in pain and still searching for a cure. A key concept in clinical treatment programs is for the patient to accept that a cure for their pain is unlikely and therefore, managing pain should be the patient’s focus. It would be interesting to see how these respondents would be doing now if they had not found a cure for their pain. Attitudes towards medication and the use of medical services varied. Overall, interviewees were self managers of their pain condition. Similarly, respondents did not rely on others to manage their pain, although many identified that they did have social support available to them. Interpretation of Quantitative Data Phases Using the interviews to evaluate the data from the quantitative phases revealed that some chronic pain respondents who had been categorised as resolved at Phase 2, still continued to have episodes of pain. These participants appeared to be different from the intermittent pain respondents that were discussed in Chapter 4, where these chronic pain participants experienced long episodes of pain and long pain-free periods (compared, for example, to people with migraine). Other research has indicated that back pain symptoms, in particular, can fluctuate (Burton et al., Chapter 7: Phase 3 – Semi-structured Interviews 243 1995); this may explain the experience of some of these respondents who were classified as having chronic pain at Phase 1 and resolved pain at Phase 2 as two of these participants had back pain and one other had multiple sites of pain including the back. Regardless, these results indicate that to capture the total experience of pain, more frequent follow-up data collection may be required. Exploration of three items taken from the Survey of Pain Attitudes (Jensen et al., 2003; Jensen et al., 1994) revealed that some items may not have been interpreted the way they were intended by these interviewees. Since the SOPA was developed with clinical patient sample, this data highlights the importance of this kind of exploration when using an established measure in a new population (i.e., a population other than the one it was developed in). Limitations of the Research Unfortunately, while an attempt was made to select participants with a range of pain experiences as identified through the questionnaire phases of this research, the final sample consisted mostly of people who continued to have constant or recurrent episodes of pain. While, this provided a comprehensive account of coping with pain, some of the aspects of the processes underlying resolved pain may not have been forthcoming. However, there were no differences between nonparticipators and participators on the key variables at baseline or follow-up. Regardless, the experience described here is that of a sample of people with pain (primarily) who responded to a request for an interview. Chapter 7: Phase 3 – Semi-structured Interviews 244 Chapter Summary The results of the semi-structured interviews highlighted that people with constant and severe pain can continue to live a functional life, that is, engage in meaningful activities, maintain employment and enjoy family or social recreation. Respondents of this research phase spoke about a number of keys aspects to coping with pain, which included staying positive, prioritising a good night’s sleep, continuing to do activities that you enjoy, and pushing through the pain. Little support was found for Gatchel’s Model in terms of the way that these people with pain described pain or their experiences with pain. However, as these people are clearly coping better than might be predicted by Gatchel’s Model, this is perhaps not surprising. Chapter 8: Discussion & Conclusions 245 CHAPTER 8: DISCUSSION & CONCLUSIONS Purpose and Overview of the Research This program of research had a dual focus. First, this research aimed to provide much needed data on the pain experience of people in the community. This information is required to expand our knowledge of the broader experience of pain, including acute and intermittent pain conditions. Knowledge of the total spectrum of pain is important for two reasons. This knowledge can be used to inform healthcare planning and to provide the foundation for the development of transitional models of acute to chronic pain. In addition, treatment and rehabilitation planning relies on sound understanding of transitional processes to develop appropriate interventions which can be provided in a community setting, prior to disability behaviour becoming entrenched. The community data provided in this thesis also provides population-specific Queensland data, which has not previously been available. This data may be able to be used for healthcare planning and service provision requirements in Queensland particularly, and in combination with previous New South Wales data (Blyth et al., 2004; Blyth et al., 2001; Blyth, March, & Cousins, 2003), may be applied to other Australian states. It provides a comprehensive (deep) description of chronic pain in a community sample, and allows comparisons to be made with patient data, of which there is much literature available. The second aim of this research was to explore the key variables of Gatchel’s Model of the Transition from Acute to Chronic Pain in a non-patient sample of Chapter 8: Discussion & Conclusions 246 people with chronic pain. In addition, emerging variables taken from the literature (risk and protective factors) were explored to examine their value as an extension to the basic model proposed by Gatchel. A critical examination of transition models, like that proposed by Gatchel, is vital to aid our understanding of how chronic pain disability develops in order to target interventions to prevent or manage chronic pain. Both of these research aims were met through three research phases using a mixed-method research approach. Phase 1 used a baseline questionnaire to collect quantitative data from 801 community-dwelling adults, and allowed the experience of pain in this community sample to be documented. An initial examination of the key variables in Gatchel’s Model was undertaken using cross-sectional analyses. Phase 2 utilised quantitative data collected using a follow-up questionnaire with a subset of the original sample (N = 218). This phase permitted the key variables from Gatchel’s Model to be examined over time, and the predictive value of the risk and protective factors to be assessed. Semi-structured interviews gathered qualitative data for Phase 3, which permitted the experience of pain in a small subset of the original sample (N = 20) to be described using this rich data source. In addition, Phase 3 enabled an in-depth examination into the reasons that evidence for some of the hypothesised relationships based upon Gatchel’s Model was not found in the earlier research phases. The Experience of Pain in a Community Sample Quantitative data was collected and collated for three pain groups. Overall this data provides an indication of how an individual’s pain experience is influenced by their type of pain, how individuals engage with healthcare systems, and whether Chapter 8: Discussion & Conclusions 247 community chronic pain samples are comparable to clinical pain samples (including the use of coping strategies taught in clinical settings). Characteristics of the Different Pain Subgroups This research collected data from and categorised pain respondents as having acute (≤ 3 months on ≥ 4 days/ week), intermittent (≤ 3 days/ week) or chronic (> 3 months on ≥ 4 days/ week) pain. These categories were based on the IASP definitions of acute and chronic pain (IASP, 1986; Merskey & Bogduk, 1994) and reflect the severity at which acute and chronic pain conditions exist. However, whether these categories are useful, when describing the pain experience of a community sample, is unknown. In this community sample, aside from the pain characteristics which differed as a result of the definitional components used to categorise respondents, there were a number of differences in the way that respondents experienced their pain condition. Participants with chronic pain were more likely to report more than one site of pain than respondents with acute or intermittent pain. In addition, chronic pain respondents reported that their pain interfered with a greater number of daily activities compared to the acute or intermittent pain respondents. Consistent with this report, approximately one-quarter of chronic pain respondents were classified as Grade IV using the Graded Chronic Pain Scales, which is described as high disability – severely limiting. This was different from the participants with acute or intermittent pain. On the one hand, interviewees with chronic pain showed great flexibility in their management of pain (by changing the way they performed or ordered activities) and pain was a clear influence on their decisions, activities and Chapter 8: Discussion & Conclusions 248 employment. On the other hand, interviewees insisted that their pain had not changed them or their life. In Phase 3, participants with acute pain provided less description of their pain experience than chronic pain respondents, and generally had shorter interviews. They tended to place less emphasis on pain’s influence on their life, seeing it as a temporary phase. This was consistent with the data in Phase 1 which showed that few acute respondents reported previous episodes of this type of pain. Also consistent with this outlook was that acute respondents were the most likely to consult a physiotherapist in the first instance (24%), which may indicate that these respondents believed their injury was treatable. Regardless, acute pain participants also reported a greater number of pain-related limitations on their activities compared to intermittent pain respondents. Consistent with this finding, a higher proportion of the acute pain participants were classified at Grades III and IV (on the Graded Chronic Pain Scales) than the intermittent pain respondents. Respondents also reported differences in the way in which pain had affected their employment. While few acute participants were unemployed because of their pain condition, people with acute pain more commonly accessed sick or workers’ compensation leave than the other pain respondents. None of the intermittent respondents were unemployed due to their pain and few reported that their pain influenced their employment in terms of leave or changed work conditions. Interestingly, despite differences in the amount of disability reported across the pain subgroups, there were no differences in the rates of depressive symptoms and anxiety in the pain samples. Across all subgroups high levels of depressive symptoms were reported by approximately 20%. Approximately 40% of each of the pain subgroups reported high levels of anxiety. Chapter 8: Discussion & Conclusions 249 In summary, it appears that the different types of pain are associated with different experiences beyond those related to their definitional differences. In particular, respondents with chronic pain are more disabled in aspects of daily life as measured via standardised questionnaires and are more likely to be unemployed due to their pain, although they describe great flexibility in managing their pain. Acute pain participants in contrast have a short term focus with their pain. However, all pain types were associated with significant psychological distress. Influence on Healthcare Systems Most participants had engaged with the healthcare system about their pain, with over 80% of the acute and intermittent pain respondents and 95% of the chronic pain respondents seeking treatment for their pain. As noted previously, the first source of medical attention was most commonly a general practitioner. While data on the frequency of healthcare visits was not collected, the large proportion of the sample that continued to receive treatment may indicate that, as reported in other research (see Maetzel & Li, 2002 for a review), pain is likely to be an economic burden on Queensland’s healthcare system. In another Australian sample from New South Wales, Blyth et al. (2004) found that chronic pain associated with greater interference (score of ≥4 on a single item 5-point adjective scale) was related to greater use of healthcare including visits to general practitioners, emergency departments, and hospital admissions. Compared to pain-free adults, people with chronic pain also reported a greater number of visits to general practitioners, emergency departments and hospital admissions. While no information on pain duration or other pain characteristics was available for this New South Wales sample, these results compliment the findings of Chapter 8: Discussion & Conclusions 250 this research where two-thirds of this sample continued to receive treatment for their pain. Clearly, chronic pain results in the ongoing use of healthcare services; this is true for a community sample of people with chronic pain and is an additional healthcare burden beyond the pain services provided to clinical patients. Somewhat inconsistent with the results of the questionnaire data was the general opinion, expressed during Phase 3, that interviewees would prefer not to seek treatment through traditional primary care or specialist physicians. Most interviewees also preferred to avoid or minimise the use of and/ or strength of pain medication consumed. The frequent report that people minimised their use of pain medication conflicts with data from the New South Wales sample where oral medications (including vitamin supplements) were taken by 70% of this sample over the previous 6-month period (Blyth, March, & Cousins, 2003). As no data was collected on vitamin supplements in this research, this data is difficult to compare across studies. Anecdotally, many interviewees mentioned the consumption of supplements. Perhaps the majority of oral medications/ supplements reported by the New South Wales sample are actually non-prescribed vitamin or herbal remedies. With regard to treatment and other healthcare services, as many of the interviewees recognised the benefits of alternate treatments (e.g., acupuncture, chiropractic or massage) and chose these treatments over surgery or medication, perhaps many of the current sample who were still receiving treatment for their pain were accessing this treatment through non-traditional means. These conclusions need to be interpreted with caution as the interviewees were a small subset of the total sample and may not represent the views of the total sample or the broader population of people with pain. Further research to fully investigate treatment Chapter 8: Discussion & Conclusions 251 preference and use in terms of traditional and non-traditional health services is recommended. Such research may assist with service planning and provision. Comparison of Chronic Pain in this Community Sample with Clinical Samples As noted in Chapter 2, the majority of the research into chronic pain has been conducted with clinic patient samples (e.g., Cannella et al., 2007; Heinberg et al., 2004; Keeley et al., 2008; McCracken & Eccleston, 2005, 2006). However, people with chronic pain who present to pain clinics are only a small subset of the total population of chronic pain sufferers. In addition, as clinical patients are actively seeking medical treatment, they may represent people with chronic pain who are coping less well with their pain. Greater understanding of the majority of people with chronic pain relies on research with community samples, and may inform clinical treatment by detailing the coping strategies and strengths of people with chronic pain who are self managers of their pain condition. The experience of chronic pain in this community sample varied considerably and appeared to be quite different to that reported by clinical samples of people with chronic pain. However, like clinical samples (Harris et al., 2003; Strong et al., 1990) (McCahon et al., 2005), there were more women than men in the current sample. Chronic pain respondents were the least likely of the pain groups to have completed tertiary education and were older than the other groups. This is consistent with prevalence studies that have found that lower education (Bergman et al., 2001; Rustøen et al., 2004) and older age (Elliott et al., 1999; Ng et al., 2002; Rustøen et al., 2004) are risk factors for chronic pain. Also like clinical samples (McCahon et al., 2005; Strong et al., 1990), pain duration for chronic pain ranged widely from 4 months to 40 years. The lower back Chapter 8: Discussion & Conclusions 252 area was the most common primary site of pain, consistent with other research (Dionne, 1999; B. F. Walker et al., 2004). Although these participants met the definition for chronic pain on the occasion when they completed the baseline questionnaire (i.e., pain ≥ 4 days per week for > 3 months), approximately 40% indicated that they had experienced this type of pain on numerous occasions, suggesting that they had pain-free episodes also. Interview data also supports this inference; three interviewees experiencing a new episode of pain at Phase 3 were classified as being pain-free at Phase 2. As discussed in Chapter 4, pain-related anxiety scores for the chronic participants were similar to those reported in a clinical sample using the same instrument (McCracken & Dhingra, 2002). Therefore it seems that community samples of people with chronic pain, outside a clinical setting, may experience high levels of pain-related anxiety symptoms. This pain-related anxiety is also related to their ability to function. In addition, the acute pain sample was similarly affected by pain-related anxiety. While a comparison of depressive symptoms is difficult due to the varying measures of depression used, transforming the CES-D scores into equivalent Beck Depression Inventory scores (Fountoulakis et al., 2007) indicates that this sample reported less symptoms of depression than would be expected based on clinical norms (Nicholas, Asghari, & Blyth, 2008). While pain resulted in interference in activities of daily living and social, family and recreational activities, based on published norms for clinical samples the chronic pain respondents in this sample had lower daily interference than clinical patients (RMDQ; M = 8.20; SD = 5.8 vs M = 12.3; SD = 5.7) (Nicholas et al., 2008). Although the most common site of pain was the low back region, it is possible that the pathology associated with the respondents’ pain in the current sample was less Chapter 8: Discussion & Conclusions 253 severe than would be seen in a clinical sample. Some caution is warranted in interpreting the results of this study for people whose source of pain is not musculoskeletal in nature. Consistent with the finding of lower daily interference, the chronic pain respondents in this sample had higher pain-related self efficacy (PSEQ; M = 42.0; SD = 13.7 vs M = 25.5; SD = 13.8) based on these same published norms (Nicholas et al., 2008). Chronic pain respondents also reported coping well with their pain during the interview phase; this was contradictory to Australian normative clinic data (Nicholas et al., 2008). While chronic pain respondents provided low endorsement on the standardised measures of coping strategies (i.e., CPCI and CSQ), during the Phase 3 interviews, respondents reported that a positive attitude and keeping active were the key aspects to coping. Many of the interviewees described being able to integrate these aspects into the management of their pain. Regardless of the differences (or similarities) between this community sample and published patient data, it cannot be overlooked that it is possible that some of the participants of this research may have also been patients of a pain clinic. It was not the intention of the research to target clinical patients. Participation in this research was not linked with a healthcare service, which allowed a potentially wider community sample to be obtained. However, the quantitative responses of this sample indicated that the majority of the people with chronic pain had sought treatment as some stage for their pain and many continued to receive healthcare for their pain. It is not clear where they were receiving this current treatment nor did respondents provide data on all the previous pain-related treatments which they had received. However, in the interviews, participants expressed a preference not to use specialist physicians. While the responses of the majority of the interviewees Chapter 8: Discussion & Conclusions 254 indicated that they were not clinical patients nor likely to become clinical patients in the future, regardless, the possibility that participants from the wider sample were also patients of pain-related healthcare services cannot be ruled out. An Exploration of Gatchel’s Model A primary aim was to explore Gatchel’s Model of the acute to chronic pain transition and examine possible extensions to this model. A diagram of the model is presented in Chapter 2 on page 25. Using quantitative data, the components of Gatchel’s Model were examined in two ways; comparing people with acute vs. chronic pain using a cross-sectional design in Phase 1 and tracking changes in mental and physical de-conditioning over time for those whose pain persisted at follow-up (Phase 2). The key components of Gatchel’s model were also discussed in the semi-structured interviews at Phase 3. The data are discussed with regard to the fit of Gatchel’s Model with this non-clinical sample and the value of the additional risk and protective factors in explaining the development of chronic pain or increasing disability. Fit between Gatchel’s Model and the Pain Experience of this Community Sample Overall, the experience described by this community sample did not fit well with Gatchel’s Model. Regardless, an aspect of Gatchel’s Model that was consistent with the experience of these respondents was that the two de-conditioning syndromes (i.e., mental and physical de-conditioning) were related to each other as proposed by the model. At baseline, moderate positive correlations were reported between measures of disability, depressive symptoms and anxiety. Further, some interviewees articulated that there was a link between their emotional state and Chapter 8: Discussion & Conclusions 255 activity levels, although this was mostly referred to using a positive framework; where being active was viewed as improving one’s emotional or mental state. Also contradictory with the processes described by the model, over a 3-month follow-up period, changes in disability, depressive symptoms and anxiety were not associated with each other in a way that suggested that changes in one would produce changes in the other. In this sense, evidence that one de-conditioning syndrome influenced the other was absent. A finding of this research was that the experience of this community sample was not time dependent in the way that it is described in Gatchel’s Model. When the measures of de-conditioning (two self-report measures of disability, one measure of depressive symptoms and one measure of pain-related anxiety) were examined in relation to time since pain onset (i.e., pain duration), duration was not correlated with these variables in cross-sectional analyses (see Chapter 5) nor did pain duration predict future disability (see Chapter 6). Further, over the 3-month follow-up period, depressive symptoms and global disability actually decreased even though these chronic pain respondents still had pain. While, Gatchel’s Model predicts that pain leads to inactivity an examination of the groups at a cross-sectional level (Phase 1) showed that physical deconditioning was present in chronic pain respondents, many participants of the Phase 3 interviews specifically spoke about remaining active despite pain. Some people remained active by changing the way they perform tasks, seeking help or going slower. In addition, there were a number of strategies that interviewees cited as being important to remain active. These strategies included being prepared, stepping back rather than rushing in to a commitment or a task, not measuring themselves Chapter 8: Discussion & Conclusions 256 against others and doing activities that they enjoyed. For the majority of these participants, pain did not lead to significant physical inactivity. Examination of two common types of mental de-conditioning revealed that pain duration was not correlated with depressive symptoms or pain-related anxiety at baseline or follow-up (as noted earlier). Regardless, some interviewees spoke about the influence that their emotional state had on their pain experience. Rumination and feeling depressed about their situation were seen by interviewees to have a negative influence on their experience of pain and life in general. In conclusion, Gatchel’s Model did not fit well with the data from this study. While the data supported the links between mental and physical de-conditioning, the course of the de-conditioning processes was not supported. There were a number of strategies that respondents used, which may have minimised de-conditioning. These strategies (that is, staying positive and remaining active) are those which health professionals already encourage with patient samples. While replication of these results is required, this data suggests that Gatchel’s Model does not capture the processes involved in the development of continuation of chronic pain in non-patient samples. Exploring the Extension Variables (Risk & Protective Factors) A number of risk factors for the development of chronic pain and factors that were proposed to be protective against the development of chronic pain were assessed. These variables were also included in this research to gauge their usefulness for inclusion in Gatchel’s Model to explain some of the underlying processes that may exist during the course of chronic pain (not explained by mental and physical de-conditioning syndromes as they currently stand). Chapter 8: Discussion & Conclusions 257 Due to the recruitment strategy used, the overall sample in this research consisted of a greater proportion of women and was older than would be expected based upon Australian census data. As a result, two of the proposed risk factors (that is, gender and age) were not able to be explored with this data. The other risk factors, fear-avoidance beliefs, catastrophising (which was a factor score derived from the CSQ, CPCI and SOPA subscales), and the belief that one will not return to work, were examined. These risk factors were positively associated with the measures of de-conditioning and pain intensity, and negatively correlated with the protective factors. These findings demonstrate that, in this community sample, these three risk factors were correlated in the expected theoretical direction. Likewise, the associations between the protective factors and de-conditioning measures were in the predicted direction, with the exception of social support (which was not correlated with the disability measures). The predictive ability of each of the risk and protective factors on each of the de-conditioning measures was assessed in Phase 2 (see Chapter 6). Despite high inter-correlations between the risk and protective factors (which may have minimised their opportunity for unique prediction), significant predictors of physical de-conditioning were self efficacy and Limiting Activities (a derived coping factor). The significant predictors of each of the mental de-conditioning syndromes differed somewhat. Depressive symptoms were predicted by optimism, social support, Influence of Emotion (coping factor: belief that one’s emotional state influences their pain experience) and Catastrophising (coping factor) whereas anxiety was predicted by self efficacy, fear-avoidance beliefs, Limiting Activities, Use of Distraction (active coping factor), Influence of Emotion and Catastrophising. These findings suggest that self-efficacy may be important for both the physical and Chapter 8: Discussion & Conclusions 258 psychosocial components of chronic pain. The other psychosocial variables typically have the greatest influence on the emotional or psychological components of chronic pain. Predicting the Development of Chronic Pain The prediction of the development of chronic pain was of particular interest for this research. Gatchel’s Model did not provide a useful framework for this prediction. As noted in Chapter 6, the conclusions of this research about the development of chronic pain are limited by the small numbers of participants who reported acute pain at baseline and continued to have pain at follow-up. Regardless, two predictors of the development of chronic pain were identified. These were rural residence and higher depressive symptom score at baseline. Greater depressive symptoms are consistent with Gatchel’s Model; potentially these participants displayed signs of early mental de-conditioning. However, since this was true for half of the new chronic pain respondents only, the predictive utility of this variable is limited. Future large-scale research which specifically targets people with acute pain is required to further tease out these relationships. Predicting the Continuation of Pain In addition to predicting the development of chronic pain, the factors that predicted continued disability were explored. These analyses aimed to assess the value of the variables from Gatchel’s Model and also the additional risk and protective factors. When predicting those with continued chronic pain compared to those for whom chronic pain would resolve, two predictors of continued pain were observed. These included a constant pattern of pain and very high perceived social Chapter 8: Discussion & Conclusions 259 support. This finding provided some evidence for one of the proposed protective factors, although in this case very high perceived social support was a risk factor for continued pain. Transposing the Extension Variables onto Gatchel’s Model One of the objectives of this research was to evaluate the value of the proposed extension variables with the view that one or more of these may be a useful addition to Gatchel’s Model. This was a significant objective of the research. A clear theoretical framework to guide research into the development or prediction of chronic pain has been lacking in much of the pain literature. It was proposed that if Gatchel’s Model could provide this basic model on which to base our understanding of these processes, then hanging the influence of these proposed extension variables (on chronic pain development) onto Gatchel’s Model would be useful. Because the findings of this research program did not support the utility of Gatchel’s Model in a non-patient sample, the basic model was not well supported. For this reason, the utility of 'adding on' the significant risk and protective factors identified in this investigation was not clear. Instead, the pattern of results may be better understood from other theoretical perspectives and these perspectives are considered next. Contribution to Theory This research found limited support for the constructs and processes described by Gatchel’s Model. It is therefore important to consider alternate theories as a basis for understanding the process of the development and Chapter 8: Discussion & Conclusions 260 continuation of chronic pain in non-patient groups; the majority of people with chronic pain. Two other primary theories of chronic pain development are the FearAvoidance Model (Vlaeyen et al., 1995) and more recently, the AttachmentDiathesis Model of Chronic Pain (ADMoCP) (Meredith, Ownsworth, & Strong, 2008). Fear-Avoidance Model The Fear-Avoidance Model of Exaggerated Pain Perception, originally proposed 1983, was based on the premise that a fear of pain may lead to two opposite outcomes; confrontation or avoidance of the “threat” (Lethem, Slade, Troup, & Bentley, 1983). Avoidance was proposed to lead to exaggerated pain perception. The Fear-Avoidance Model was developed later as not only fear of pain but fear of movement that may cause pain, or fear of (re)injury was identified was an important factor (Vlaeyen et al., 1995). This fear of (re)injury in addition to pain catastrophising is believed to underlie fear-avoidance behaviour resulting in disability, depression and pain-related anxiety. The Fear-Avoidance Model has much support in the literature. For example, fear-avoidance beliefs have been found to be superior predictors of both selfreported and objective measures of disability (compared to negative affect, pain intensity or pain catastrophising) in chronic pain patient samples (e.g., Crombez et al., 1999). In addition, psychological treatments based on the Fear-Avoidance Model of chronic pain, which aim to expose individuals to activities previously avoided due to fear of (re)injury, have been shown to be successful (Woods & Asmundson, 2008). Chapter 8: Discussion & Conclusions 261 The results of this research also offer some support for the Fear-Avoidance Model. For example, fear avoidance beliefs were positively correlated with current pain, level of disability, pain-related anxiety and depressive symptoms (all r’s ≥ .36; see Table 25; Chapter 5). In addition, fear-avoidance beliefs were a significant predictor of disability (see Tables 26 and 27; Chapter 5) and anxiety (see Table 29; Chapter 5). However, caution should be used when considering these results in light of the Fear-Avoidance Model because fear of (re)injury was not specifically assessed. Still, it may be appropriate to conclude that these results can be understood within this framework and may offer some indirect support for the FearAvoidance Model. Attachment-Diathesis Model of Chronic Pain The ADMoCP contains four main sections: attachment diathesis, cognitive appraisals, responses of the individual (emotions, coping behaviour and strategies) and impact on adjustment to pain (Meredith et al., 2008). It is proposed by this model that pain is a stressor that triggers cognitive appraisals (e.g., of pain and available support) and emotional, cognitive and behavioural responses to this stressor (e.g., coping strategies) as per the attachment diathesis an individual has. Any vulnerabilities (due to attachment insecurities), the cognitive appraisals and the response of the individual all affect how well the individual manages, copes with or adjusts to pain and their wellness in spite of pain. Given that the ADMoCP has been published only recently, there is little research directly examining the variables that this model posit as important. The results of the current research also do not shed light on the mechanisms proposed by the ADMoCP. Although, some further evidence for the ADMoCP may be that few Chapter 8: Discussion & Conclusions 262 people have insecure attachments (van Ijzendoorn, 1995) and few people access specialist medical pain treatment in order to manage their pain condition. Greater research is needed to evaluate the usefulness of the ADMoCP in research and clinical settings. As this research found limited support for the constructs and processes described by Gatchel’s Model, it is recommended that either of these two alternate models be examined for use with community samples to further our understanding of the processes of the development of chronic pain. In deciding which model to pursue in future research, the Fear-Avoidance Model is recommended. There are two reasons for this recommendation. First, the Fear-Avoidance Model has a longer research history to substantiate it and therefore may be regarded as more wellestablished. Second, it provides a better fit with data from this research than the ADMoCP, although it must also be acknowledged that there was more overlap between the variables assessed in this study and the variables of the Fear-Avoidance Model than the variables of the ADMoCP. Practical Applications The results of this research support at least one of the treatment goals of pain clinics. Interview respondents talked at length about the importance of maintaining employment or links with other meaningful activity, which is not related to their pain experience. As the primary goal for pain clinics is to encourage patients to become more physically active and engage in meaningful activities despite pain (McCracken, 1998; McCracken & Eccleston, 2005), it is encouraging that respondents who have not accessed this type of clinical service have found that engaging in meaningful activity is possible and useful in the self-management of Chapter 8: Discussion & Conclusions 263 their pain. It may also be possible to use the strategies that these research respondents had found helpful – including making preparations before starting a task, not measuring themselves against others and doing things that they enjoy – to encourage people with pain to maintain their activity levels. The participants in this research most often had first sought healthcare through general practitioners. It would therefore seem that general practitioners are best placed to provide information about the basic physiology of pain and managing pain by staying active. If this is not a service that general practitioners are able to provide, general practitioners may be best placed to refer to other community-based pain-specific treatment services. In Australia, as more and more general practice centres include other allied health consultants (such as clinical nurses, psychologists, physiotherapists, and pharmacists), it seems practicable and valuable for community-based pain specialists to be included in these primary care centres. In this manner, individuals very early in the pain trajectory could access guidelines and healthcare advice about managing their pain before disability became entrenched. Effective short-term intervention at this early stage has the potential to be very cost effective. While caution is warranted in the interpretation of the data about the continuation of chronic pain (as noted previously, replication of this result is required), these results indicate that practitioners should be wary of the effects of secondary rewards via very strong social support on the experience of chronic pain. As other authors have noted (Flor, Kerns, & Turk, 1987; Paulsen & Altmaier, 1995), involvement of the patients’ significant others may be necessary to improve functioning and meet activity goals. Chapter 8: Discussion & Conclusions 264 Finally, the use of a mixed-method approach in this research has demonstrated that practitioners using standardised pain questionnaires with a community population should be wary about how respondents interpret some items. While these questionnaires are standardised and have demonstrated reliability and validity in clinical samples, most pain questionnaires were developed with clinical (and often treatment) samples. Clinical patients have therefore been exposed to the language that is used in clinical environments and often in these questionnaires. Without further research, practitioners cannot be confident that the underlying construct that the items are designed to measure is actually been captured in a population sample. Future research that generates community-based normative data may be helpful to address this gap in the literature. Strengths and Limitations of this Research There are a number of strengths to this program of research. This project is one of the first pain-specific community survey conducted in Australia (see also Blyth, March, & Cousins, 2003) and the first longitudinal study of risk factors for chronic pain in Australia. Previous population-based research into pain in Australia has focused on specific pain sites groups (e.g., lower extremities (Chen et al., 2003), low back pain (B. F. Walker et al., 2004)) or population groups (e.g., elderly people (Chen et al., 2003)). Data on broader population groups or pain sites has been gained through more general health surveys (Blyth et al., 2001). Therefore, this research addresses an important gap in knowledge in terms of examining the influence and experience of pain (including chronic pain) in a community sample. The overall scope of the research and nature of the data collection was considerable. The research encompassed data on pain variables, disability and Chapter 8: Discussion & Conclusions 265 psychosocial variables using multi-method data collection and included a comprehensive questionnaire with follow-up and qualitative data. A wide-ranging methodology was used to obtain both standardised measurement of pain variables and in-depth exploration of the pain experience from the viewpoint of people with pain. The value of including the qualitative component into the program of research was evident when a comparison was made between the questionnaire and interview data; it is difficult to comprehensively categorise people’s pain experience using a questionnaire. Design features, such as longitudinal data collection and multi-method techniques, were incorporated to explore the experience of pain; the use of these features adds to the reliability and utility of the overall findings. The combination of quantitative data and qualitative data allowed specific hypotheses to be tested (proposed on the basis of Gatchel’s Model), comparative data to be collected for reference to previous and future pain data sets, as well as the lived experience of pain to be described. All of which allow clinicians and researchers to gain a fuller understanding of the processes involved in acute and chronic pain. The use of a theoretical framework to guide the research, including the inclusion of risk and protective variables, is another strength of this program of research. Explaining how and why a variable exerts its influence is equally important as the finding that a psychological variable is linked with chronic pain (Linton, 2000; Pincus et al., 2002). One of the criteria applied to the inclusion of these extension variables was that they would act on one of the two de-conditioning processes proposed by Gatchel’s Model (that is, mental or physical de-conditioning). Predominantly, previous pain research has been atheoretical (e.g., Galizzi & Boden, 2003; McCracken & Eccleston, 2005). This is particularly true for research that has Chapter 8: Discussion & Conclusions 266 examined the relationships between pain and other variables in community samples (e.g., Benjamin et al., 2000; Karoly & Ruehlman, 2006). However, the value of theory or theoretical models to provide a basis for understanding the relationships between variables cannot be understated. The results of this research improve our understanding of the utility of a prominent theoretical framework (Gatchel's model) in the area. To the author’s knowledge, this is the first empirical examination of some of the key processes that underlie Gatchel’s Model. This is an important advance for pain research, as Gatchel’s Model has been presented in the literature for over a decade without direct empirical review. Even though this model did not provide a good description of the pain experience of participants, we now know something more about the generalisability of this framework beyond clinical pain samples. Regardless, some limitations of the research need to be considered. As described in Chapters 5 and 6, in terms of the measurement of Gatchel’s concepts, self-report disability measures provide only a proxy estimate of objective disability. In order to address this issue and increase the reliability of the results two different self-report measures of disability were utilized. While the measures were strongly correlated (r = .6), there was not 100% overlap between the two, indicating that each instrument tapped into different aspects of disability. This enabled a more comprehensive examination of disability to be achieved, but the proxy nature of this measurement needs noting as a potential limitation. Similarly, a limitation of this research is how mental de-conditioning was operationalised; this was also described in Chapters 5 and 6. Gatchel (1991a) describes mental de-conditioning as “the development of a “layer” of behavioral and psychological problems that occur in response to the chronic pain and the patients’ Chapter 8: Discussion & Conclusions 267 attempts to cope with it” (Gatchel, 1991a, p. 280). These behavioural or psychological problems are of sufficient strength to “prevent the individual from maintaining a productive lifestyle” (Gatchel, 1991a, p. 280) in order to be considered mental de-conditioning. As can be seen from this description, mental deconditioning encompasses a vast number of behavioural or psychological problems. Due to the relatively narrow conceptualisation of mental de-conditioning used, this research was unable to capture all of the possible mental de-conditioning processes and was not tailored to each participant’s predisposition to particular psychological problems. Regardless, this research focused on the two most common manifestations of mental de-conditioning, that is, depression and anxiety, to try to capture the majority of mental de-conditioning syndromes. Future research would need to assess personality characteristics prior to individuals’ developing chronic pain to attempt to address the limitations of this study. Previously, Gatchel has relied on the MMPI-2 to capture personality data. While the MMPI-2 is the most commonly used personality measure (Deardorff, 2000), there is some controversy about it use and the usefulness of the data it provides (Deardorff, 2000). In addition, its length and the restricted conditions of use prohibit its use with a large community sample, like the one used in this research. Nevertheless, if future research uses Gatchel’s Model in a non-clinical sample, this discussion may inform attempts to operationalise concepts from that model, identify ways of improving on the methods used here, and contribute to recognition of important methodological considerations. Another limitation of this study, highlighted previously, is that it is difficult to assess the representativeness of the sample as the pain-free respondents consisted of a greater number of women and were older than would have been predicted by Chapter 8: Discussion & Conclusions 268 Australian census data. While this does not necessarily preclude the representativeness of the pain samples, it does indicate that caution should be applied when interpreting these results in the context of the wider Australian community. The findings of this research may be more applicable to women and older adults with pain. However, as previous research has indicated, female sex and older age are risk factors for chronic pain (Blyth et al., 2001; Elliott et al., 1999; Rustøen et al., 2004), it is likely that these results may be applied to the majority of people with pain. This research aimed to use a broader sample of the general population than previous studies to broaden the applicability of these results beyond employee (e.g., Hagen et al., 2000; Karjalainen et al., 2001b) or patient samples (e.g., McCahon et al., 2005; McCracken & Eccleston, 2005). This objective was not achieved due to the low response rate and small number of acute participants who developed chronic pain. While the recruitment strategy achieved a random sample of households, using a non-addressed postal package meant that follow-up of non-respondents was not possible. As discussed in Chapter 4, other research may have achieved higher response rates through the use of addressed correspondence and multiple nonrespondent reminders. Regardless, the small numbers of people who developed pain during the course of the research means that some important variables may not have been captured due to low power. The sample consisted of adults who voluntarily participated and therefore could be considered to have self selected into the research. It can be argued that the effects of self selection, however, were minimised (at least in part) by randomly targeted households to receive the baseline questionnaire and specifically targeting people with pain. Nonetheless, it remains possible that this sample reflects those Chapter 8: Discussion & Conclusions 269 people with chronic pain who are coping most well with their pain and, therefore, have the time and energy to participate. Alternatively, the sample may consist of people with less severe pain or less severe psychological symptoms. This latter interpretation seems unlikely as the anxiety levels reported by this sample were similar to those reported by some clinical samples (McCracken & Dhingra, 2002). Additionally, an attempt was made to minimise some of these possible biases by offering an incentive to participate by way of a competition to win a holiday voucher. In addition, to reduce taxing potential participants, people were instructed that they could complete the questionnaire in multiple sittings and a reply-paid envelope was provided so that there were no out-of-pocket expenses associated with participation. Given the length of the baseline questionnaire and the tiring effects of pain, obtaining a sample of over 400 participants with pain is noteworthy. Recall also that the rate of chronic pain in the selected households for this research was consistent with previous Australian prevalence research (Blyth et al., 2001). This suggests that a good response rate for those with chronic pain was achieved. In addition, a good response rate at follow-up was achieved which is consistent with other large-scale community research (e.g., Bergman et al., 2002; Elliott et al., 2002). While self-report measures are a typical and accepted methodology in this area (Blyth et al., 2001; Linton, 2005; McCracken & Eccleston, 2006), the reliance on self-report measures for the variables assessed in Phases 1 and 2 may be viewed as a limitation of the research. However, some of the key variables assessed in this research (e.g., depressive symptoms and beliefs) are only able to be captured by self report (Asghari & Nicholas, 2001). In addition, the use of well-validated and specific assessment tools allowed for the comparison of the findings of this research Chapter 8: Discussion & Conclusions 270 with previous studies. Regardless, using self-reported disability in this research may have resulted in artificially inflated relationships between disability and other (self reported) psychosocial variables due to measurement error and was complicated by the fact that some measures were developed for clinical samples as noted previously. The design of future research and interpretation of the current findings should be cognisant of these theoretical and practical limitations. Future Directions This program of research has highlighted a number of areas for future research, which have been mentioned previously. These include research which specifically targets community-dwelling adults who are coping less well with their pain perhaps through community-based health services such as general practitioners or other allied health services. Such research would compliment the current research to provide a further opportunity to inform community early interventions for those who require such treatments. Equally, research that targets men and younger adults (i.e., 18-35 years) would add to our knowledge of the pain experience over the spectrum of the lifespan and for men (who were under-represented in the current sample). Likewise, an examination of the use of medication and other treatments in the management of chronic pain in a community setting would provide a clearer picture of the current cost of chronic pain in non-patient populations. While Gatchel’s Model does not appear to generalise well outside a patient population and was not a useful framework for understanding the experience of pain of this community sample, this research did not provide a true test of this model. Replication of this research that addresses the measurement limitations, described earlier, may help determine whether Gatchel’s Model provides a useful framework Chapter 8: Discussion & Conclusions 271 to understand the pain experience in a community samples. Use of objective measures of disability and assessment of personality prior to the development of chronic pain would strengthen the assessment of this model. However, given the discussion of other theoretical frameworks to understand the experience of pain in this sample, further research which utilises the Fear-Avoidance Model is also warranted. Similarly, examination of the risk and protective factors that were identified in the current research as important either in the development or continuation of pain is necessary. In summary, research of the nature described is required to better understand how people with chronic pain mange their pain and further examine some the important factors in the transition to chronic pain. Research of this kind may assist to reduce the burden of chronic pain. Conclusion The current program of research examined the experience of chronic pain in a community sample, assessed the utility of a conceptual model of acute to chronic pain transition proposed by Gatchel (1991a) in a non-clinical sample, and evaluated a number of risk and protective factors that may be useful extensions to this model. Overall the findings highlight a number of issues. First, chronic pain in a community sample is associated with significant disability and psychological distress. It would appear that the pain experience of people with acute, intermittent and chronic pain is different across a number of variables including disability levels and influence on employment. This sample reported similar levels of pain-related anxiety but lower levels of depressive symptoms and physical disability when compared to clinical samples. 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Appendices 303 APPENDICES Appendix A: Comparison between Brisbane and rural respondents available for the Phase 3 (interview) study Table A1 Demographic Variables for Participants willing to be contacted for Interview by Location Variable Female (%) Statistical comparison ∞ Urban respondents (N = 127) 57.5 Rural respondents (N = 36) 77.8 χ² (1, n = 163) = 4.90, p = .027* 65.1 80.6 χ² (1, n = 162) = 3.11, p = .078 Partnered (%) Highest level of education (%) χ² (4, n = 159) = 12.96, p = .011* Primary school 8.1 2.8 Year 10 23.6 52.8 Year 12 6.5 8.3 TAFE or equivalent 35.0 25.0 University 26.8 11.1 Age in years: Mean (SD) 56.73 (13.18) 52.11 (13.26) t (159) = 1.85, p = .066 # adults in the household: 2.02 (.82) 2.19 (.82) t (157) = -1.09, p = .278 Mean (SD) Table A2 Pain Variables for Participants willing to be contacted for Interview by Location Variable Urban respondents (N = 127) Rural respondents (N = 36) Statistical comparison ∞ Mean SD Mean SD Depression (CES-D) 15.31 11.63 17.26 11.55 t (161) = -0.89, p = .374 Anxiety (PASS) 28.90 20.00 31.92 21.90 t (159) = -0.78, p = .436 Daily interference (RMDQ) 7.60 5.92 7.64 5.54 t (161) = -0.37, p = .971 Global disability (GCPS) 36.75 27.72 37.31 25.16 t (157) = -.11, p = .912 Pain intensity (GCPS) 51.35 21.20 51.20 16.76 t (160) = 0.04, p = .970 Appendices 304 Appendix B: Baseline (Phase 1) Questionnaire Appendices 315 Appendix C: Comparison between pain respondents who provided pain duration and respondents who did not provide pain duration at baseline Table C1 Demographic Variables for Baseline Pain Participants by Whether Pain Duration data was provided Female (%) 62.5 Respondents who did not provide pain duration (N = 28) 44.4 Partnered (%) 73.0 74.1 Variable Respondents who provided pain duration (N = 450) Highest level of education (%) Statistical comparison ∞ χ² (1, n = 446) = 3.50, p = .061 χ² (1, n = 445) = 0.02, p = .900 χ² (4, n = 440) = 9.22, p = .056 Primary school 7.8 10.7 Year 10 28.4 17.9 Year 12 11.4 28.6 TAFE or equivalent 26.9 14.3 University 25.5 28.6 51.92 (15.25) 54.46 (17.49) t (442) = 0.84, p = .397 2.18 (.86) 2.44 (1.05) t (435) = 1.55, p = .121 Age in years: Mean (SD) # adults in the household: Mean (SD) Appendices 316 Appendix D: Participant Information Sheet Appendices 319 Appendix E: Examining Gatchel’s Model with Low Back Pain Respondents Table E1 Correlations between Pain Duration and Measures of Gatchel’s Variables at Baseline (shaded) and Follow-Up (unshaded) for Low Back Pain Respondents (N = 47)^ Daily Pain Overall interfer. intensity disability -.039 -.094 -.132 -.094 1 .623** .457** .499** .607** -.077 .721** 1 .757** .617** .760** Daily interference -.158 .512** .667** 1 .554** .740** Pain Intensity .018 .590** .416** .470** 1 .599** Global disability -.152 .623** .760** .780** .593** 1 Duration Depression Anxiety 1 .145 Depression .034 Anxiety Duration Note. Depression: Center for Epidemiologic Studies – Depression, Anxiety: Pain Anxiety Symptoms Scale, Daily interference: Roland Morris Disability Questionnaire, Pain intensity: GCPS Graded Chronic Pain Scales – Intensity estimate, Global disability: GCPS Graded Chronic Pain Scales – Disability estimate ^ The value of N varies due to missing data ** p<.01 Table E2 Correlation Matrix for Changes Scores on Psychological and Disability Measures for Low Back Pain Respondents (N = 47)^ CES-D change PASS change RMDQ change Disability estimate change CES-D change PASS change RMDQ change Disability est. change 1 .154 -.123 .195 1 .174 .146 1 .452** 1 Note. CES-D Center for Epidemiologic Studies – Depression, PASS Pain Anxiety Symptoms Scale, RMDQ Roland Morris Disability Questionnaire, GCPS Graded Chronic Pain Scales & Disability estimate ^ The value of N varies due to missing data * p<.01 ** p<.001 Appendices 320 Table E3 Comparing Gatchel’s Variables between Baseline and Follow-up data collection for Low Back Pain respondents (N = 47) Dependent variables Baseline 3-month Follow-up t-tests M SD M SD Depression (CES-D) 17.84 13.13 16.74 11.35 t (43) = 1.00, p = .325 Pain-related anxiety (PASS) 36.22 22.65 35.28 23.67 t (45) = 0.52, p = .606 Daily interference (RMDQ) 8.91 5.96 9.06 6.09 t (46) = -0.26, p = .795 Global disability (GCPS) 40.36 26.79 36.81 26.29 t (45) = 1.34, p = .188 Table E4 Frequencies (%) of GCPS Classification Changes for Low Back Pain Respondents Classification change N % 2 grade decrease (better) 3 6.4 1 grade decrease (better) 12 25.5 No change 16 34.0 1 grade increase (worse) 4 8.5 Note. % does not sum to 100% because 12 respondents did not have change scores calculated. Grade decreases indicate that respondents had a reduction in the severity of their pain. Grade increases indicate that respondents’ pain worsened.