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Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Tobacco stained fingers: a clue for smoking related disease or harmful alcohol use? A case-control study. Journal: BMJ Open rp Fo Manuscript ID: Article Type: Date Submitted by the Author: Complete List of Authors: bmjopen-2013-003304 Research 27-May-2013 Secondary Subject Heading: Addiction, Respiratory medicine, Cardiovascular medicine, Diagnostics INTERNAL MEDICINE, Cardiology < INTERNAL MEDICINE, Thoracic medicine < INTERNAL MEDICINE, Adult oncology < ONCOLOGY, PREVENTIVE MEDICINE, Substance misuse < PSYCHIATRY w ie Keywords: Smoking and tobacco ev <b>Primary Subject Heading</b>: rr ee John, Gregor; Geneva University Hospitals (HUG), Internal Medicine Pasche, Séphora; Geneva University Hospitals (HUG), Department of Community Medicine, Primary Care and Emergency Medicine Rothen, Nicole; Bern University hospital, Internal Medicine Charmoy, Alexia; Lausanne University Hospital (CHUV), Anaesthesiology Delhumeau-Cartier, Cecile; Geneva University Hospitals (HUG), Infectious disease Genne, Daniel; HNE La ChauxdeFonds, Internal Medicine ly on For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 1 of 24 BMJ Open TOBACCO STAINED FINGERS: A CLUE FOR SMOKING RELATED DISEASE OR HARMFUL ALCOHOL USE? A CASE-CONTROL STUDY. Authors: During the study, except Cécile Delhumeau-Cartier*, all authors were working in rp Fo the Department of Internal Medicine, Hôpitaux Neuchâtelois, La Chaux-de-Fonds, Switzerland. Gregor John, MD (correspondence to and requests for reprints); Department of Internal medicine, Geneva University Hospitals (HUG), Gabrielle-Perret-Gentil 4, CH-1205 Geneva, ee Switzerland, Phone number: 0041 79 553 43 08, [email protected] (may be published). rr Sephora Pasche, MD; Department of Community Medicine, Primary Care and Emergency ev Medicine, Geneva University Hospitals (HUG), Geneva, Switzerland; [email protected] Nicole Rothen, MD; -Department of Internal Medicine, Bern University hospital, Bern, Switzerland; [email protected] w ie Alexia Charmoy, MD; Department of Anaesthesiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland, [email protected] on Cécile Delhumeau-Cartier*, PhD, statistician; Department of Internal Medicine, Geneva University Hospitals (HUG), Geneva, Switzerland; [email protected] ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Daniel Genne, Professor; Department of Internal Medicine, Hôpitaux Neuchâtelois, La Chaux-de-Fonds, Switzerland; [email protected] Key words (MeSh) : Smoking; Alcohol Drinking; Physical examination; Pulmonary Disease, Chronic Obstructive; cardiovascular disease. Word count: Abstract: 253, Article: 2405 1 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open ABSTRACT Objective: Tobacco stain on fingers is frequent. However, there is scarce description of this clinical sign. We aimed to explore tobacco stain on fingers as a marker of tobacco related disease, or of harmful alcohol use, independent of cumulative tobacco exposure. Design: Case-control study Setting: A Swiss community hospital of 180 beds. rp Fo Participants: 49 adults presenting tobacco-tars staining on fingers were matched to 49 control smokers by age, gender, height, and pack-year. Outcome measures: Documented smoking related carcinoma, ischemic heart disease, peripheral arterial disease, stroke, and chronic obstructive pulmonary disease (COPD) also ee determined by lung function, were compared between groups. Association between harmful alcohol use, mental disorders, or unemployment, and tar-staining was adjusted for smoking rr behaviour through conditional logistic regression. Results: Overall cigarette related disease was high in the case group (84%), and ev symptomatic peripheral arterial disease was more frequent compared to controls (OR 3.5, CI95% 1.1-14.6). Smoking-related carcinoma (OR 1.5, CI95% 0.5-5.1), ischemic heart ie disease (OR 0.8, CI95% 0.4-2.3), stroke (OR 0.5, CI95% 0.1-3.5), and COPD (OR 2.2, w CI95% 0.7-8.1) were not statistically different to control smokers. Harmful alcohol use was strongly associated with stains and this association persists after adjustment for smoking on unfiltered cigarettes, smoking more than one pack of cigarette in a day, and age at smoking ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 2 of 24 onset (adjusted OR 4.6, CI95% 1.2-17.2). Mental disorders and unemployment were not statistically significant. Conclusions: Tobacco-tar stained fingers seem to identify high-risk smokers due to the tobacco exposure, rather than a specific increased susceptibility. Harmful alcohol use should be explored among these patients. 2 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Page 3 of 24 ARTICLE SUMMARY Article focus • Identification of smokers at high risk of smoking related disease could impact their management. • A deeper puff could result in higher tar deposition on skin and greater inhalation of tobacco, putting the lung and distant organs at increased health hazard • rp Fo Apart from cigarette characteristics, behavioural and environmental factors may be important in stain development. Key messages • Tobacco-tar stained fingers give clue for a tobacco related conditions four times out of five. However, tobacco-tar stained fingers seem to identify high-risk smokers due to the rr • ee tobacco exposure, rather than a specific increased susceptibility • ev The study suggests a link between this tar-stained fingers and addictive behaviour or concomitant high alcohol consumption that should be taken into account in smoking cessation and prevention programs. • w Strengths and limitations of this study ie This case-control study explores an easily identifiable and frequent clinical sign on among smokers and appreciates the additional risk for health due to tar deposition (influenced by puffing or cigarettes characteristics) not included in the usual measure of tobacco exposure (PY). • ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open Diagnoses were obtained from medical records or from patients self-reporting, subject to recall bias. Problematic alcohol consumption was not measured with established instruments (e.g. AUDIT). The sample size was small. 3 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open INTRODUCTION "The yellow finger stain is an emblem of deeper degradation and enslavement than the ball and chain." Henry Ford, The Case Against the Little White Slaver (Detroit: 1914) Tobacco use is the leading cause of preventable death around the world. The 2011 World rp Fo Health Organization report on the global tobacco epidemic predicted that if current trends persist, more than eight million people worldwide will die from tobacco related disease each year by 2030.[1] Although cigarette smoking is by far the most common risk factor for chronic ee obstructive pulmonary disease (COPD), is strongly associated with cardiovascular disease, and is responsible for 30% of all cancer deaths, additional factors are involved in determining rr each individual’s susceptibility to tobacco related disease.[2-3] Identifying smokers at higher risk of developing disease could improve their management and screening programs.[4] ev Smoking has been linked to many skin conditions for more than 150 years and evidence ie exist that skin involvement might be a conspicuous marker of other tobacco related w disease.[5] For example, smoking related wrinkles have been associated with a decrease in lung function independent of tobacco exposure.[6] The “yellow rounded digit” and “Harlequin on nail” signs are two other simple clinical signs which aid the diagnosis of health conditions.[7- ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 4 of 24 8] The former, characterised by fingers that are both tobacco-stained and clubbed, raises suspicion of lung carcinoma. The latter is seen after acute cessation of cigarette consumption resulting in a bi-colour nail (the distal end is cigarette stained contrasting the newly growing proximal part) and is a reliable marker of concurrent disease. We hypothesised that tar deposition itself (figure 1) could be a marker of tobacco related disease independent of cumulative tobacco exposure. A deeper puff could result in higher tar 4 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 5 of 24 BMJ Open deposition on skin and greater inhalation of tobacco, putting the lung and distant organs at increased health hazard. Tobacco-stains on fingers are commonly seen among smokers but there is scarce description of this phenomenon. Apart from cigarette characteristics, behavioural and environmental factors may be important in stain development. Epidemiologic studies worldwide show higher rate of smoking among people suffering from mental or substance use disorders.[9-10] Yellow stained fingers often observed in psychiatric units and among rp Fo young drug users (autopsy series) supports a possible association between those conditions and tar deposition.[11-12] ee We conducted the present study to determine whether tar deposit is an independent marker of tobacco related disease and to identify factors associated with stain development, such as rr alcohol consumption, psychiatric conditions, unemployment, and smoking habits. METHODS ie Study design and population ev We performed a case-control study between March 2006 and January 2010 in a 180-bed w community hospital in La Chaux-de-Fonds, Switzerland. Eligible patients were adult current on smokers admitted to the departments of internal medicine or surgery, or the intensive care unit, irrespective of diagnosis or cause of admission. We excluded patients unable to provide ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com informed consent, those post thoracic surgery or suffering from an ear–nose–throat (ENT) conditions which could prevent lung function testing, patients receiving palliative care, and pregnant women. Cases were defined by presence of tobacco stains on their fingers, and were reported to the study group by the medical team or identified by the group through frequent screening. They were included consecutively to avoid selection bias. Controls were selected randomly from the same population, to fulfil the matching criteria. All participants provided written informed consent. Institutional Review Board approved the study. 5 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Measures and outcomes of interest Four physicians dedicated to the study collected all information. The main investigator checked data accuracy using the study information and medical charts. A single thirty-minute standard interview was performed for each participant to obtain a medical history, a physical exam, and to perform pulmonary function tests. Investigations were performed at least one month after an exacerbation of a chronic pulmonary condition, pneumonia, or acute heart failure. Forced expiratory volume in one second (FEV1) and the forced vital capacity (FVC) rp Fo were assessed using Microloop spirometer (Micro Medical Limited, England). Tobacco-related disease A history of tobacco-related disease – ischemic stroke (haemorrhagic or cardio-embolic ee events excluded), coronary heart disease (CHD), peripheral arterial disease (PAD), tobacco- rr related carcinoma (lung, urinary tract, or ENT), and COPD- was obtained from the patient’s interview and from past and current medical records, classified according to the International ev Statistical Classification of Diseases, tenth revision (ICD-10).[13] COPD was also assessed on lung function, when FEV1/FVC was less than 70%.[14] We defined coronary heart disease ie (CHD) as a history of angina pectoris, myocardial infarction, coronary arterial bypass graft, w arterial angioplasty, or known vessel obstruction of 50% or more. Leg pain associated with ankle brachial ratio index less than 0.9 or a procedure for arterial insufficiency defined a on peripheral arterial disease (PAD). We recorded coughing, sputum production, and the degree of dyspnea according to the New York Heart Association classification (NYHA).[15] ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 6 of 24 Factors for stains development: We documented any mental disorders diagnosed according to DSM-IV criteria and antidepressant, benzodiazepine, neuroleptic, or mood stabilizer use.[16] We considered harmful alcohol use when high alcohol intake –more than fourteen standard drinks per week for women and more than twenty-one standard drinks per week for men (140g and 210g of alcohol respectively)- was associated with documented withdrawal, medical consequences 6 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 7 of 24 BMJ Open (neurologic, cardiac, hepatic, or pancreatic), or erythrocyte macrocytosis (mean corpuscular volume greater than 98 fl) not otherwise explained.[17] Occupations were classified according to the six-class version of the National Statistics Socio-Economic Classification.[18] Previous occupation was considered for retired individuals. Smoking habits reviewed were: age at onset, number of packets smoked per day, unfiltered, or low tar cigarettes, and attempts at smoking cessation. Patients were questioned on the number of years the stains have been present, their rp Fo tendency to extend, their impact on everyday life, and attempts to make them disappear. We recorded the number and location of stains for each patient as well as the surface area in centimetres squared of stain located on finger skin only. The intensity of all stains was graded using a standardised visual scale from one to five depending on the colour (pale yellow to intense brown). ev rr Statistical analysis ee We paired one control for every case, and matched them individually by age, gender, height, and pack-years smoked (PY). Pairs were matched closely with up to ten percent difference ie for each continuous variable. We then compared the predicted value of FEV1 (according to w height, age, and gender) of each pair to ensure a difference of <10%.[19] The PY was calculated as the number of packs smoked in a day multiplied by the number of years spent on smoking. When the consumption was irregular from day to day we used the mean of the extremes as an estimate of the number of packs smoked daily. If the consumption was ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com higher or lower for more than a year’s duration, the total cumulative PY was calculated as the sum of the different PYs throughout life. We calculated that 50 participants in each group would allow us to detect a threefold increase of tobacco related disease in the cases group (odds ratio), using McNemar test with a two-sided alpha of 5% and a power of 80%, if at least 30% of pairs are discordant. To compare groups, we used McNemar test for binary variables and paired Wilcoxon test for 7 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open continuous variables. Among the case group, we used Spearman rank correlation to test for an association between measured FEV1 and stain characteristics. Conditional logistic regression was used to assess the association between cigarette staining and mental health condition, psychotropic medications, harmful alcohol use, occupational categories, and smoking behaviours. We built a parsimonious multivariate model, guided by the analyst, entering each potential variable one by one, starting with those strongly associated and clinically relevant, and keeping only statistically significant and mutually rp Fo adjusted variables in the final model. With about 50 events (cases) and a requested number of 10-15 events per variable we expected a maximum of 4-5 variables in the final model.[20] We performed post hoc sub-analyses excluding pairs in which controls notified finger/nail ee stains in the past. Since those analyses showed similar results, only results of the initial analyses are shown. ev rr Analyses were performed on cases and controls with complete documented information. Data analyses were perform by using STATA 10.1 (StataCorp LP, Texas, USA). This study ie received no external funding source and volunteers received no financial reward. w RESULTS Participants: ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 8 of 24 Between March 2006 and December 2007, 4520 patients were admitted to the hospital, of which 1127 were current smokers (25%). Among those current smokers, 63 (6%) presented one or more tar staining on the hand. Nine refused to participate and five could not be matched, resulting into 49 cases. The corresponding 49 controls were included between February 2007 and January 2010. All participants were Caucasians (Table 1). 8 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Page 9 of 24 For one participant stain characteristics were impossible to determine due to a peripheral cyanosis at the time of examination. The 48 other cases possessed a total of 153 stains; 64% on nail and 36% on finger skin (Table 2). Among the controls, eleven (22%) reported the presence of at least one stain on fingers within their lifetime but not at the time of the study. Tobacco related disease, and lung function test: Although there was a slight increase in vascular disease, COPD, and smoking related cancer rp Fo in the case group, the difference was not statistically significant (Table 3). Peripheral arterial disease was more prevalent among the case group with 14/49 (29%) complaining of claudication and 12/49 (24%) having undergone revascularization procedure compared to 5/49 (10%; p=0.049) and 2/49 (4%; p=0.006) respectively in the control group. rr ee Lung function tests were not available for three controls. Measured FEV1 was not statistically different between groups. Thirteen cases (26%) and 11/46 (24%) controls had less than ev 50% of expected FEV1. Stain number (r: 0.13, p=0.39), mean size (r: 0.24, p=0.25), and median colour intensity (r: 0.22, p=0.13) had no influence on measured FEV1 among cases. Factors associated with tar staining: w ie Smoking more than one pack of cigarettes per day, smoking unfiltered cigarettes, having on more cigarette breaks, harmful alcohol use, or being on psychotropic medication were all associated with higher risk of tar staining in univariate analyses (Table 4). Use of low tar ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open content cigarettes was less frequent among tobacco stain participants. In a multivariate analysis, four factors remained significantly associated with stain: smoking more than one pack per day, smoking unfiltered cigarettes, age at onset, and harmful alcohol use. Adding more variables produced artificially high OR due to insufficient events-pervariable. These four factors accounted for 41% of variance (pseudo-R2) in the presence of stains. 9 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open DISCUSSION Our case-control study explores an easily identifiable and frequent clinical sign among smokers. A tar stained finger gives clue for a tobacco related conditions four times out of five. Furthermore, this clinical sign is linked to harmful alcohol use. As far as we know this is the first description of this particular category of smokers. The design of the study appreciates the additional risk for health due to tar deposition rp Fo (influenced by puffing or cigarettes characteristics) not included in the usual measure of tobacco exposure (PY). Yet the high incidence of COPD, overall cardiovascular disease, and tobacco-related carcinomas are not independently related to tar deposition. PAD, found in ee excess among finger stained individuals, might be due to an alpha error, related to the sample size. Besides, similar lung function between case and control groups and the rr absence of relationship between FEV1 and stain characteristics among cases are consistent with a lack of association between yellow fingers and obstructive lung disease. Thus yellow ev staining is rather a proxy of the consequences of tobacco: its presence in itself seems to identify high-risk smokers due to the tobacco exposure, rather than a specific increased susceptibility. w ie Four variables mutually adjusted – smoking more than one pack of cigarette in a day or on unfiltered cigarettes, age at smoking onset, and harmful alcohol use – could explain a substantial part of stain development, even in individuals matched for characteristics that are ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 10 of 24 probably linked to stains (pack-year, age, and gender). Our results suggest that staining is influenced by the characteristics of cigarettes smoked and smoker’s behaviour. Indeed, finger stained smokers seem to present a more severe addictive behaviour (high proportion of harmful alcohol use, early age at smoking onset, high number of cigarettes smoked per day, and few cigarette breaks). An industry-funded study concluded that psychological and personality constructs were positively associated with depth of inhalation.[21] Apart from 10 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 11 of 24 BMJ Open puffing characteristics, smoking the entirety of cigarettes, seen among addict individuals, might also contribute to tar staining. Previous studies have shown that the proportion of alcohol disorders increases with cigarette consumption, and that daily tobacco use increases with the level of alcohol consumption.[22-23] Our study is the first to demonstrate an association between harmful alcohol use and tar staining independent of the extent of tobacco consumption. Alcohol consumption in itself could influence smoking behaviour, which in turn impacts on tar deposition. Nil and colleagues reported increased puff volume following consumption of 0.7 g/kg of ethanol.[24] This addictive behaviour and concomitant rp Fo high alcohol consumption must be taken into account in tobacco cessation programs. The study has several limitations. First, many diagnoses were obtained from medical records or from patients self-reporting. Thus the study was dependent of the quality and ee completeness of medical charts and subject to recall bias. This assessment might also cover rr a specific fraction of mental disorders (those who seek professional help). Second, tobacco dependence or problematic alcohol consumption were not measured with established ev instruments (e.g. AUDIT). “Harmful alcohol use” is not a standard definition and includes MCV which has a low specificity. Furthermore, the observers were not blinded to the ie allocation (case vs. control) of the patients, which could influence clinical interview. However, w the results are plausible, and future studies should used standard tools to confirm them. Third, a lack of statistical power might have underestimated the effect of yellow fingers on on study outcomes. Moreover, 22% of controls reported transient tar discoloration in the past, which might have blurred the effect. However, tar deposition appears to be constant over ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com time in the case group, and a transient finger staining could be a clinically insignificant event. Finally, our observations are limited to the inpatient hospital setting and may have to be confirmed in finger-stained patients seen outside this context. In a world of growing technology and complicated diagnosis procedure, our work highlights the importance of clinical assessment of smokers; an important message to transmit in medical education. This costless and easy obtainable information should stress tobacco- 11 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open related disease screening and reinforce smoking counselling. Harmful alcohol use should be explored among these patients. ACKNOWLEDGEMENTS We gratefully acknowledge Sebastian Carballo, Fraser Easton and Andrew Stewardson for their correction of the English manuscript. rp Fo COMPETING INTERESTS All authors declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work. ev rr FUNDING ee This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors CONTRIBUTORSHIP w ie We confirm that all authors have participated in conception and design, or analysis and on interpretation of data, drafting the article or revising it critically for important intellectual content: ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 12 of 24 Drs John and Genné had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: John and Genné. Acquisition of data: Pasche, Rothen, Charmoy, John. Analysis and interpretation of data: Delhumeau-Cartier, John.Drafting of the manuscript: John. Critical revision of the manuscript for important intellectual content: Delhumeau-Cartier, Pasche, Rothen, Charmoy and Genné. Statistical analysis: Delhumeau-Cartier, John. Study supervision: Genné. 12 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 13 of 24 BMJ Open DATA SHARING The full dataset can be obtain by request to the corresponding author REFERENCES: 1. World Health Organziation. Report on the global tobacco epidemic. http://www.who.int/tobacco/global_report/2011/qanda/en/index.html, 2011. Date last rp Fo update: september 2011. Last access date: november 2012. 2. Ezzati M, Lopez AD. Regional, disease specific patterns of smoking-attributable mortality in 2000. Tob Control 2004;13(4):388-95. 3. Office of the Surgeon General. How tobacco smoke causes disease the biology and ee behavioral basis for smoking-attributable disease : a report of the Surgeon General. Dept. of Health and Human Services, Public Health Service, 2010. rr http://www.surgeongeneral.gov/library/reports/tobaccosmoke/full_report.pdf.Last access date: november 2012. ev 4. Aberle DR, Adams AM, Berg CD, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med 2011;365:395-409. ie 5. Solly S. Clinical lectures on paralysis. The Lancet 1856;63:669-71. w 6. Lange P, Schnohr P. The relationship between facial wrinkling and airflow obstruction. Int J Dermatol 1994;33:123-6. on 7. Levine H. The yellow rounded digit: sign of the times. N Engl J Med 1968;279:660-1. ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 8. Verghese A, Krish G, Howe D, Stonecipher M. The harlequin nail. A marker for smoking cessation. Chest 1990;97:236-8. 9. Lawrence D, Mitrou F, Zubrick SR. Smoking and mental illness: results from population surveys in Australia and the United States. BMC Public Health 2009;9:285. 10. Kalman D, Morissette SB, George TP. Co-morbidity of smoking in patients with psychiatric and substance use disorders. Am J Addict 2005;14:106-23. 11. Thakurdas H. Smoking and Psychiatrc Patient. Br Med J 1963;388. 13 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open 12. Hafezi M, Bohnert M, Weinmann W, Pollak S. Prevalence of nicotine consumption in drug deaths. Forensic Sci Int 2001;119(3):284-9. 13. World Health Organisation. International statistical classification of diseases and related health problems. Instruction Manual v. 2: Tenth Revision. Geneva, Switzerland: World Health Organisation 2004. 14. Global Initiative for Chronic Obstructive Lung Disease (GOLD), Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease. , (2006). http://www.who.int/respiratory/copd/GOLD_WR_06.pdf. Last access date: rp Fo november 2012. 15. The Criteria Committee of the New York Heart Association. Nomenclature and Criteria for Dagnosis of Diseases of the Heart and Great Vessels. 9 ed. Boston, MA: Little, Brown, 1994. ee 16. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. rr 4 ed. Washington, DC: American Psychiatric Association, 1994. 17. World Health Organziation. Lexicon of alcohol and drug terms published by the World ev Health Organization. http://www.who.int/substance_abuse/terminology/who_lexicon/en/. Last access date: november 2012. ie 18. The National Statistics Socio-economic Classification (NS-SEC rebased on the w SOC2010), 2010. http://www.ons.gov.uk/ons/guide-method/classifications/currentstandard-classifications/soc2010/soc2010-volume-3-ns-sec--rebased-on-soc2010--usermanual/index.html. Last access date: november 2012. on 19. Hankinson JL, Odencrantz JR, Fedan KB. Spirometric reference values from a sample of ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 14 of 24 the general U.S. population. Am J Respir Crit Care Med 1999;159:179-87. 20. Courvoisier DS, Combescure C, Agoritsas T, Gayet-Ageron A, Perneger TV. Performance of logistic regression modeling: beyond the number of events per variable, the role of data structure. J Clin Epidemiol 2011;64:993-1000. 21. Wood D, Wilkes E. Project Wheat - Part 1 Cluster Profiles of U.K. Male Smokers and Their General Smoking Habits. Report No. Rd.1229-R., 1960. 14 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Page 15 of 24 http://tobaccodocuments.org/product_design/1208809.html. Last access date: november 2012. 22. Friedman GD, Tekawa I, Klatsky AL, Sidney S, Armstrong MA. Alcohol drinking and cigarette smoking: an exploration of the association in middle-aged men and women. Drug Alcohol Depend 1991;27:283-90. 23. Dawson DA. Drinking as a risk factor for sustained smoking. Drug Alcohol Depend 2000;59:235-49. 24. Nil R, Buzzi R, Battig K. Effects of single doses of alcohol and caffeine on cigarette rp Fo smoke puffing behavior. Pharmacol Biochem Behav 1984;20:583-90. w ie ev rr ee ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open 15 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Table 1 Baseline characteristics of the yellow-stained finger cases and their controls smokers. Values are numbers (percentage) unless stated otherwise. Variables Cases (n=49) Controls (n=49) P value* Matching .65 † 59 (50 - 69) 62 (50 - 69) Median (IQR) age (years) Male 32 (65) 32 (65) .99 .84 † 170 (165 - 175) 170 (165 - 177) Median (IQR) height (centimetres) ‡ Median (IQR) pack years’ smoked 50 (40 - 61) 46 (38- 58) .20 † § .60 † 3.2 (2.4 - 3.7) 3.3 (2.4 - 3.8) Median (IQR) predicted FEV1 (litres) || Diagnosis category on admission .48 15 (31) 11 (22) Cardiovascular Neurologic 7 (14) 6 (12) .99 .79 6 (12) 8 (16) Oncology Infectious disease 5 (10) 5 (10) .99 .99 5 (10) 6 (12) Traumatology Others 12 (24) 12 (24) .99 * McNemar and exact test unless stated otherwise † Paired Wilcoxon sign-rank test ‡ Number of packs smoked in a day multiplied by the number of years spent smoking or sum of the different PYs throughout life if the consumption was higher or lower for more than a year’s duration § Predicted FEV1 calculated according to the third National Health and Nutrition Examination Survey formula18 || Category of main diagnosis claimed on the exit chart FEV1: maximal forced expiratory volume in one second; PY: pack year unit; 95%CI: 95% confidence interval; IQR: interquartile range 25-75% w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 16 of 24 16 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 17 of 24 BMJ Open Table 2 Stains characteristics in cases. Value are numbers of cases (percentage) unless stated otherwise Stains characteristics Cases N(%)* Time of stain appearance (years) 15 (31) 1-4 5-9 2 (4) 31 (65) ≥10 Suffering due to the stain 3 (6) 23 (48) Physical/chemical attempt to remove the stain Variation over time (stain size or intensity) 18 (37) 3 (2-4) Median (IQR) stains per cases Median (IQR) nails stained 2 (1-2) 1 (0-3) Median (IQR) stains on skin Median (IQR) number of fingers discoloured per cases 3 (2-3) 25 (52) First finger 45 (94) Second finger 37 (77) Third finger 1 (2) Fourth finger 0 (0) Fifth finger 1.9 (1.2-3.1) Median (IQR) total skin area stained per cases (square centimetre) * Stain location, size, and colour intensity were impossible to determine for one patient due to peripheral cyanosis at the time of examination. In another three cases, the precise size of stains present on skin (five stains) was not measured because of scant demarcation of the stain. IQR: interquartile range 25-75% w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 17 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Table 3 Tobacco-related diseases and respiratory complaints. Values are numbers (percentage) unless stated otherwise Cases Controls N pairs OR(CI 95%) p value* Tobacco-related disease Any tobacco-related disease † 41 (84) 39 (80) 49 1.3 (0.4-4.1) .80 .83 0.9 (0.4-2.3) 49 26 (53) 25 (51) Vascular disease Coronary arterial disease ‡ 17 (35) 19 (39) 49 0.8 (0.3-2.1) .67 .69 0.5 (0.1-3.5) 49 6 (12) 4 (8) Strokes/TIA§ Peripheral arterial disease || 15 (31) 5 (10) 49 3.5 (1.1-14.6) .03 .13 2.2 (0.7-8.1) 47 24 (49) 31 (63) COPD FEV1/FVC<70% 25 (51) 17 (37) 46 1.1 (0.4-3.5) .11 .59 1.3 (0.4-4.7) 49 20 (41) 22 (45) Clinical diagnosis ¶ ** Smoking-related Cancer 10 (20) 7 (14) 49 1.5 (0.5-5.1) .61 Respiratory complaints Coughing 32 (65) 25 (51) 49 2.2 (0.8-6.9) .11 .28 1.8 (0.5-6.8) 49 15 (31) 19 (39) Sputum production †† ‡‡ Median (IQR) grade dyspnoea 1 (1-2) 1 (0-2) 49 .14 §§ .004 4.5 (1.5-18.3) 49 10 (20) 24 (49) Abnormal lung auscultation Median (IQR) FEV1 (litre) 1.9 (1.3-2.5) 1.9 (1.4-2.6) 46 .49 ‡‡ * McNemar exact test † At least one vascular disease, BPCO, or smoking-related carcinoma ‡ Self reporting angina pectoris, heart infarction, coronary arterial bypass graft, percutaneous angioplasty or more than 50% vessel obstruction on coronary catheterization § Stroke or a transient neurologic symptoms except traumatic, haemorrhagic, or cardio embolic event || Self reporting symptomatic arterial claudication, ankle brachial ratio less than 0.9, or chirurgical or radiological procedure for arterial insufficiency ¶ Self reporting or documented in the medical record ** Carcinoma of lung, urinary tract, or head and neck †† According to the New York Heart Association functional capacity classification ‡‡ Paired Wilcoxon sign-rank test §§ Wheezing or crackles N pairs: number of pairs used in the analysis; OR: Odds ratio; FEV1: maximal forced expiratory volume in one second; FVC: forced vital capacity; TIA: transient ischemic attack; COPD: chronic obstructive pulmonary disease; CI95: 95% confidence interval; IQR: (interquartile range 25-75%) w ie . ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 18 of 24 18 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 19 of 24 Table 4 Smoking behaviour, mental health, harmful alcohol use, and occupation categories in univariated and multivariated conditional regression model. Values are numbers (percentage) unless stated otherwise Univariated Multivariated Cases Controls OR (CI 95%) p value aOR (CI 95%) p value Fo Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 BMJ Open Smoking habits Median (IQR) age at beginning (years) 17 (15-20) 18 (15-20) 1.5 (1.0-2.4) * .06 2.1 (1.1-4.0) * .02 † † Median (IQR) number pack per day 1 (1-1.8) 1 (1-1.5) 3.9 (1.2-12.7) .02 8.5 (1.9-38.4) .006 Nb of brand median (IQR) 2 (1-3) 2 (2-3) 0.9 (0.7-1.2) .39 Breaks median (IQR) 1 (0-2) 2 (1-3) 0.7 (0.5-1) .04 Nb patients smoking unfiltered cigarettes 20 (41) 9 (18) 3.2 (1.2-8.7) .02 4.2 (1.1-16.0) .03 Nb patients smoking low tar cigarettes 7 (14) 17 (35) 0.3 (0.1-0.9) .03 Mental health and harmful alcohol use Harmful alcohol use § 25 (51) 10 (20) 3.5 (1.4-8.7) .007 4.6 (1.2-17.2) .02 Others psychiatric condition || 22 (45) 14 (29) 1.7 (0.8-3.7) .18 ¶ On psychotropic medication 33 (67) 20 (41) 2.4 (1.1-5.3) .02 Occupation Unemployment 17 (35) 12 (24) 1.7 (0.7-4.3) .26 * For every two years younger than 22 years old † For every ten cigarettes more than 20 ‡ For every ten years § More than fourteen drinks per week for women, more than twenty-one drinks per week for men associated with alcohol withdrawal, or documented complications || According to the medical chart and DSMIV criteria ¶ Antidepressant, anxiolytic, neuroleptic, opioid, and antiepileptic (used as mood stabilizer) drug OR (CI95%): Odds ratio (95% confidence interval); aOR: adjusted Odds ratio; IQR: (interquartile range 25-75%) rp ee rr ev iew on ly 19 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 20 of 24 20 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 21 of 24 BMJ Open ie ev rr ee rp Fo Tar staining seen in a 70 years old men smoker (80PY). 626x534mm (72 x 72 DPI) w ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open STROBE 2007 (v4) Statement—Checklist of items that should be included in reports of case-control studies Section/Topic Title and abstract Item # 1 Recommendation Reported on page # (a) Indicate the study’s design with a commonly used term in the title or the abstract 1 Fo rp (b) Provide in the abstract an informative and balanced summary of what was done and what was found Introduction ee 2 Background/rationale 2 Explain the scientific background and rationale for the investigation being reported 4,5 Objectives 3 State specific objectives, including any prespecified hypotheses 5 Study design 4 Present key elements of study design early in the paper Setting 5 Describe the setting, locations, and relevant dates, including periods of recruitment, exposure, follow-up, and data collection 5-7 Participants 6 (a) Give the eligibility criteria, and the sources and methods of case ascertainment and control selection. Give the rationale for 5 rr Methods the choice of cases and controls Variables 7 5 ev iew (b) For matched studies, give matching criteria and the number of controls per case 7 Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if 6,7 applicable on Data sources/ measurement 8* For each variable of interest, give sources of data and details of methods of assessment (measurement). Describe comparability of assessment methods if there is more than one group Bias 9 Describe any efforts to address potential sources of bias ly 6,7 6 Study size 10 Explain how the study size was arrived at Quantitative variables 11 Explain how quantitative variables were handled in the analyses. If applicable, describe which groupings were chosen and why 7,8 7 Statistical methods 12 (a) Describe all statistical methods, including those used to control for confounding 7,8 (b) Describe any methods used to examine subgroups and interactions 8 (c) Explain how missing data were addressed 8 (d) If applicable, explain how matching of cases and controls was addressed 7 (e) Describe any sensitivity analyses 8 1 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Page 22 of 24 Page 23 of 24 Results Participants 13* (a) Report numbers of individuals at each stage of study—eg numbers potentially eligible, examined for eligibility, confirmed 8 eligible, included in the study, completing follow-up, and analysed Descriptive data 14* Fo (b) Give reasons for non-participation at each stage 8 (c) Consider use of a flow diagram - rp (a) Give characteristics of study participants (eg demographic, clinical, social) and information on exposures and potential Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 BMJ Open 8, 15-18 confounders (b) Indicate number of participants with missing data for each variable of interest 17 ee Outcome data 15* Report numbers in each exposure category, or summary measures of exposure 15-18 Main results 16 (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (eg, 95% confidence interval). Make clear which confounders were adjusted for and why they were included 8-9, 15-18 (b) Report category boundaries when continuous variables were categorized 8-9, 15-18 (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period - Report other analyses done—eg analyses of subgroups and interactions, and sensitivity analyses 7 Other analyses 17 rr ev Discussion iew Key results 18 Summarise key results with reference to study objectives Limitations 19 Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias 11 Interpretation 20 Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of analyses, results from similar 11 studies, and other relevant evidence Generalisability on ly 21 Discuss the generalisability (external validity) of the study results 22 Give the source of funding and the role of the funders for the present study and, if applicable, for the original study on which the present article is based Other information Funding 10 11 12 *Give information separately for cases and controls in case-control studies and, if applicable, for exposed and unexposed groups in cohort and cross-sectional studies. 2 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Note: An Explanation and Elaboration article discusses each checklist item and gives methodological background and published examples of transparent reporting. The STROBE checklist is best used in conjunction with this article (freely available on the Web sites of PLoS Medicine at http://www.plosmedicine.org/, Annals of Internal Medicine at http://www.annals.org/, and Epidemiology at http://www.epidem.com/). Information on the STROBE Initiative is available at www.strobe-statement.org. Fo Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Page 24 of 24 rp ee rr ev iew on ly 3 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Tobacco stained fingers: a clue for smoking related disease or harmful alcohol use? A case-control study. Journal: BMJ Open rp Fo Manuscript ID: Article Type: Date Submitted by the Author: Complete List of Authors: bmjopen-2013-003304.R1 Research 28-Jul-2013 Secondary Subject Heading: Addiction, Respiratory medicine, Cardiovascular medicine, Diagnostics INTERNAL MEDICINE, Cardiology < INTERNAL MEDICINE, Thoracic medicine < INTERNAL MEDICINE, Adult oncology < ONCOLOGY, PREVENTIVE MEDICINE, Substance misuse < PSYCHIATRY w ie Keywords: Smoking and tobacco ev <b>Primary Subject Heading</b>: rr ee John, Gregor; Geneva University Hospitals (HUG), Internal Medicine Pasche, Séphora; Geneva University Hospitals (HUG), Department of Community Medicine, Primary Care and Emergency Medicine Rothen, Nicole; Bern University hospital, Internal Medicine Charmoy, Alexia; Lausanne University Hospital (CHUV), Anaesthesiology Delhumeau-Cartier, Cecile; Geneva University Hospitals (HUG), Infectious disease Genne, Daniel; HNE La ChauxdeFonds, Internal Medicine ly on For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 1 of 42 BMJ Open TOBACCO STAINED FINGERS: A CLUE FOR SMOKING RELATED DISEASE OR HARMFUL ALCOHOL USE? A CASE-CONTROL STUDY. Authors: During the study, except Cécile Delhumeau-Cartier*, all authors were working in rp Fo the Department of Internal Medicine, Hôpitaux Neuchâtelois, La Chaux-de-Fonds, Switzerland. Gregor John, MD (correspondence to and requests for reprints); Department of Internal medicine, Geneva University Hospitals (HUG), Gabrielle-Perret-Gentil 4, CH-1205 Geneva, ee Switzerland, Phone number: 0041 79 553 43 08, [email protected] (may be published). rr Sephora Pasche, MD; Department of Community Medicine, Primary Care and Emergency ev Medicine, Geneva University Hospitals (HUG), Geneva, Switzerland; [email protected] Nicole Rothen, MD; -Department of Internal Medicine, Bern University hospital, Bern, Switzerland; [email protected] w ie Alexia Charmoy, MD; Department of Anaesthesiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland, [email protected] on Cécile Delhumeau-Cartier*, PhD, statistician; Department of Internal Medicine, Geneva University Hospitals (HUG), Geneva, Switzerland; [email protected] ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Daniel Genne, Professor; Department of Internal Medicine, Hôpitaux Neuchâtelois, La Chaux-de-Fonds, Switzerland; [email protected] Key words (MeSh) : Smoking; Alcohol Drinking; Physical examination; Pulmonary Disease, Chronic Obstructive; cardiovascular disease. Word count: Abstract: 256, Article: 2496 1 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open ABSTRACT Objective: Tobacco stain on fingers is frequent. However, there is scarce description of this clinical sign. We aimed to explore tobacco stain on fingers as a marker of tobacco related disease independent of cumulative tobacco exposure, and find behavioural and environmental characteristics associated with those stains. Design: Case-control study rp Fo Setting: A Swiss community hospital of 180 beds. Participants: 49 adults presenting tobacco-tars staining on fingers were matched to 49 control smokers by age, gender, height, and pack-year. Outcome measures: Documented smoking related carcinoma, ischemic heart disease, ee peripheral arterial disease, stroke, and chronic obstructive pulmonary disease (COPD) also determined by lung function, were compared between groups. Association between harmful rr alcohol use, mental disorders, or unemployment, and tar-staining was adjusted for smoking behaviour through conditional logistic regression. ev Results: Overall cigarette related disease was high in the case group (84%), and symptomatic peripheral arterial disease was more frequent compared to controls (OR 3.5, ie CI95% 1.1-14.6). Smoking-related carcinoma, ischemic heart disease, stroke, and COPD w were not statistically different to control smokers. Harmful alcohol use was strongly associated with stains and this association persists after adjustment for smoking unfiltered on cigarettes, smoking more than one pack of cigarette in a day, and age at smoking onset ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 2 of 42 (adjusted OR 4.6, CI95% 1.2-17.2). Mental disorders and unemployment were not statistically significant. Conclusions: Patients with tobacco-tar stained fingers frequently have cigarette related disease, however statistically not more than control smokers matched for YP, except for symptomatic peripheral arterial disease. This study suggests a link between stained fingers and addictive behaviour or concomitant high alcohol consumption. 2 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Page 3 of 42 ARTICLE SUMMARY Article focus • Identification of smokers at high risk of smoking related disease could impact their management. • A deeper puff could result in higher tar deposition on skin and greater inhalation of tobacco, putting the lung and distant organs at increased health hazard • rp Fo Apart from cigarette characteristics, behavioural and environmental factors may be important in stain development. Key messages • Tobacco related diseases (defined as smoking related carcinoma, ischemic heart ee disease, peripheral arterial disease, stroke, or chronic obstructive pulmonary disease) are frequent (84%) among patients with tobacco-tar stained fingers. • rr However, tobacco-tar stained fingers seem to identify high-risk smokers due to the ev tobacco exposure, rather than a specific increased susceptibility • The study suggests a link between this tar-stained fingers and addictive behaviour or concomitant high alcohol consumption. • w Strengths and limitations of this study ie This case-control study explores an easily identifiable and frequent clinical sign on among smokers and appreciates the additional risk for health due to tar deposition (influenced by puffing or cigarettes characteristics) not included in the usual measure of tobacco exposure (PY). • ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open Diagnoses were obtained from medical records or from patients self-reporting, subject to recall bias. Problematic alcohol consumption was not measured with established instruments (e.g. AUDIT). The sample size was small. This study included only hospital population. 3 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open INTRODUCTION "The yellow finger stain is an emblem of deeper degradation and enslavement than the ball and chain." Henry Ford, The Case Against the Little White Slaver (Detroit: 1914) Tobacco use is the leading cause of preventable death around the world. The 2011 World rp Fo Health Organization report on the global tobacco epidemic predicted that if current trends persist, more than eight million people worldwide will die from tobacco related disease each year by 2030.[1] Although cigarette smoking is by far the most common risk factor for chronic ee obstructive pulmonary disease (COPD), is strongly associated with cardiovascular disease, and is responsible for 30% of all cancer deaths, additional factors are involved in determining rr each individual’s susceptibility to tobacco related disease.[2-3] Identifying smokers at higher risk of developing disease could improve their management and screening programs.[4] ev Smoking has been linked to many skin conditions for more than 150 years and evidence ie exist that skin involvement might be a conspicuous marker of other tobacco related w disease.[5] For example, smoking related wrinkles have been associated with a decrease in lung function independent of tobacco exposure.[6] The “yellow rounded digit” and “Harlequin on nail” signs are two other simple clinical signs which aid the diagnosis of health conditions.[7- ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 4 of 42 8] The former, characterised by fingers that are both tobacco-stained and clubbed, raises suspicion of lung carcinoma. The latter is seen after an acute illness that causes cessation of cigarette consumption resulting in a bi-colour nail (the distal end is cigarette stained contrasting the newly growing proximal part). We hypothesised that tar deposition itself (figure 1) could be a marker of tobacco related disease independent of cumulative tobacco exposure. A deeper puff could result in higher tar deposition on skin and greater inhalation of tobacco, putting the lung and distant organs at increased health hazard. 4 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 5 of 42 BMJ Open Tobacco-stains on fingers are commonly seen among smokers but there is scarce description of this phenomenon. Apart from cigarette characteristics, behavioural and environmental factors may be important in stain development. Epidemiologic studies worldwide show higher rate of smoking among people suffering from mental or substance use disorders.[9-10] Yellow stained fingers often observed in psychiatric units and among young drug users (autopsy series) supports a possible association between those conditions and tar deposition.[11-12] rp Fo We conducted the present study to determine whether tar deposit is an independent marker of tobacco related disease and to identify factors associated with stain development, such as ee alcohol consumption, psychiatric conditions, unemployment, and smoking habits. METHODS ev Study design and population rr We performed a case-control study between March 2006 and January 2010 in a 180-bed ie community hospital in La Chaux-de-Fonds, Switzerland. Eligible patients were adult current smokers admitted to the departments of internal medicine or surgery, or the intensive care w unit, irrespective of diagnosis or cause of admission. We excluded patients unable to provide on informed consent, those post thoracic surgery or suffering from an ear–nose–throat (ENT) conditions which could prevent lung function testing, patients receiving palliative care, and ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com pregnant women. Cases were defined by presence of tobacco stains on their fingers, and were reported to the study group by the medical team or identified by the group through frequent screening. They were included consecutively to avoid selection bias. Controls were selected randomly from the same population, to fulfil the matching criteria. All participants provided written informed consent. Institutional Review Board approved the study. Measures and outcomes of interest 5 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Four physicians dedicated to the study collected all information. The main investigator checked data accuracy using the study information and medical charts. A single thirty-minute standard interview was performed for each participant to obtain a medical history, a physical exam, and to perform pulmonary function tests. Investigations were performed at least one month after an exacerbation of a chronic pulmonary condition, pneumonia, or acute heart failure. Forced expiratory volume in one second (FEV1) and the forced vital capacity (FVC) were assessed using Microloop spirometer (Micro Medical Limited, England). rp Fo Tobacco-related disease A history of tobacco-related disease – ischemic stroke (haemorrhagic or cardio-embolic events excluded), coronary heart disease (CHD), peripheral arterial disease (PAD), tobaccorelated carcinoma (lung, urinary tract, or ENT), and COPD- was obtained from the patient’s ee interview and from past and current medical records, classified according to the International rr Statistical Classification of Diseases, tenth revision (ICD-10).[13] COPD was also assessed on lung function, when FEV1/FVC was less than 70%.[14] We defined coronary heart disease ev (CHD) as a history of angina pectoris, myocardial infarction, coronary arterial bypass graft, arterial angioplasty, or known vessel obstruction of 50% or more. Leg pain associated with ie ankle brachial ratio index less than 0.9 or a procedure for arterial insufficiency defined a w peripheral arterial disease (PAD). We recorded coughing, sputum production, and the degree of dyspnea according to the New York Heart Association classification (NYHA).[15] ly Factors for stains development: on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 6 of 42 We documented any mental disorders diagnosed according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria and antidepressant, benzodiazepine, neuroleptic, or mood stabilizer use.[16] We considered harmful alcohol use when high alcohol intake –more than fourteen standard drinks per week for women and more than twenty-one standard drinks per week for men (140g and 210g of alcohol respectively)- was associated with documented withdrawal, medical consequences (neurologic, cardiac, 6 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 7 of 42 BMJ Open hepatic, or pancreatic), or erythrocyte macrocytosis (mean corpuscular volume greater than 98 fl) not otherwise explained.[17] Occupations were classified according to the six-class version of the National Statistics Socio-Economic Classification.[18] Previous occupation was considered for retired individuals. Smoking habits reviewed were: age at onset, number of packets smoked per day, unfiltered, or low tar cigarettes, and attempts at smoking cessation. Patients were questioned on the number of years the stains have been present, their rp Fo tendency to extend, their impact on everyday life, and attempts to make them disappear. We recorded the number and location of stains for each patient as well as the surface area in centimetres squared of stain located on finger skin only. The intensity of all stains was graded using a standardised visual scale from one to five depending on the colour (pale yellow to intense brown). ev rr Statistical analysis ee We paired one control for every case, and matched them individually by age, gender, height, and pack-years smoked (PY). Pairs were matched closely with up to ten percent difference ie for each continuous variable. We then compared the predicted value of FEV1 (according to w height, age, and gender) of each pair to ensure a difference of <10%.[19] The PY was calculated as the number of packs smoked in a day multiplied by the number of years spent on smoking. When the consumption was irregular from day to day we used the mean of the extremes as an estimate of the number of packs smoked daily. If the consumption was ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com higher or lower for more than a year’s duration, the total cumulative PY was calculated as the sum of the different PYs throughout life. We calculated that 50 participants in each group would allow us to detect a threefold increase of tobacco related disease in the cases group (odds ratio), using McNemar test with a two-sided alpha of 5% and a power of 80%, if at least 30% of pairs are discordant. To compare groups, we used McNemar test for binary variables and paired Wilcoxon test for 7 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open continuous variables. Among the case group, we used Spearman rank correlation to test for an association between measured FEV1 and stain characteristics. Conditional logistic regression was used to assess the association between cigarette staining and mental health condition, psychotropic medications, harmful alcohol use, occupational categories, and smoking behaviours. We built a parsimonious multivariate model, guided by the analyst, entering each potential variable one by one, starting with those strongly associated and clinically relevant, and keeping only statistically significant and mutually rp Fo adjusted variables in the final model. With about 50 events (cases) and a requested number of 10-15 events per variable we expected a maximum of 4-5 variables in the final model.[20] We performed post hoc sub-analyses excluding pairs in which controls notified finger/nail ee stains in the past. Since those analyses showed similar results, only results of the initial analyses are shown. ev rr Analyses were performed on cases and controls with complete documented information. Data analyses were perform by using STATA 10.1 (StataCorp LP, Texas, USA). This study ie received no external funding source and volunteers received no financial reward. w RESULTS Participants: ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 8 of 42 Between March 2006 and December 2007, 4520 patients were admitted to the hospital, of which 1127 were current smokers (25%). Among those current smokers, 63 (6%) presented one or more tar staining on the hand. Nine refused to participate and five could not be matched, resulting into 49 cases. The corresponding 49 controls were included between February 2007 and January 2010. All participants were Caucasians (Table 1). 8 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Page 9 of 42 For one participant stain characteristics were impossible to determine due to a peripheral cyanosis at the time of examination. The 48 other cases possessed a total of 153 stains; 64% on nail and 36% on finger skin (Table 2). Among the controls, eleven (22%) reported the presence of at least one stain on fingers within their lifetime but not at the time of the study. Tobacco related disease, and lung function test: Although there was a slight increase in vascular disease, COPD, and smoking related cancer rp Fo in the case group, the difference was not statistically significant (Table 3). Peripheral arterial disease was more prevalent among the case group with 14/49 (29%) complaining of claudication and 12/49 (24%) having undergone revascularization procedure compared to 5/49 (10%; p=0.049) and 2/49 (4%; p=0.006) respectively in the control group. rr ee Lung function tests were not available for three controls. Measured FEV1 was not statistically different between groups. Thirteen cases (26%) and 11/46 (24%) controls had less than ev 50% of expected FEV1. Stain number (r: 0.13, p=0.39), mean size (r: 0.24, p=0.25), and median colour intensity (r: 0.22, p=0.13) had no influence on measured FEV1 among cases. Factors associated with tar staining: w ie Smoking more than one pack of cigarettes per day, smoking unfiltered cigarettes, having on more cigarette breaks, harmful alcohol use, or being on psychotropic medication were all associated with higher risk of tar staining in univariate analyses (Table 4). Use of low tar ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open content cigarettes was less frequent among tobacco stain participants. In a multivariate analysis, four factors remained significantly associated with stain: smoking more than one pack per day, smoking unfiltered cigarettes, age at onset, and harmful alcohol use. Adding more variables produced artificially high OR due to insufficient events-pervariable. These four factors accounted for 41% of variance (pseudo-R2) in the presence of stains. 9 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open DISCUSSION Our case-control study explores an easily identifiable and frequent clinical sign among smokers. Tobacco related diseases (defined as smoking related carcinoma, ischemic heart disease, peripheral arterial disease, stroke, and chronic obstructive pulmonary disease) are frequent (84%) among patients with tobacco-tar stained fingers. Furthermore, this clinical sign is linked to harmful alcohol use. As far as we know this is the first description of this particular category of smokers. rp Fo The design of the study appreciates the additional risk for health due to tar deposition not included in the usual measure of tobacco exposure (PY). Stain may result from local pigment ee deposition secondary to high tar concentration in the skin-cigarette interface (influenced by puffing or cigarettes characteristics), but higher concentration of nicotine (and other rr substances) smoked could affect stain removal by impaired skin repair. [21] Similarly, nicotine has been shown to reduce blood flow in fingers and increase systemic blood ev pressure, a mechanism that could rationally explain the association of impaired stain removal and peripheral arterial disease. [22, 23] w ie Yet the high incidence of COPD, overall cardiovascular disease, and tobacco-related carcinomas are not independently related to tar deposition. Besides, similar lung function on between case and control groups and the absence of relationship between FEV1 and stain characteristics among cases are consistent with a lack of association between yellow fingers ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 10 of 42 and obstructive lung disease. We believe that yellow staining identifies high-risk smokers due to the tobacco exposure (PY), rather than a specific increased susceptibility (e.g. puffing characteristics). Lack of an association with investigated tobacco related illnesses other than symptomatic peripheral arterial disease, could however arise from insufficient power of the study. 10 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 11 of 42 BMJ Open Four variables mutually adjusted – smoking more than one pack of cigarette in a day or unfiltered cigarettes, age at smoking onset, and harmful alcohol use – could explain a substantial part of stain development, even in individuals matched for characteristics that are probably linked to stains (pack-year, age, and gender). Our results suggest that staining is influenced by the characteristics of cigarettes smoked and smoker’s behaviour. Indeed, finger stained smokers seem to present a more severe addictive behaviour (high proportion of harmful alcohol use, early age at smoking onset, high number of cigarettes smoked per day, and few cigarette breaks). An industry-funded study concluded that psychological and rp Fo personality constructs were positively associated with depth of inhalation.[24] Apart from puffing characteristics, smoking the entirety of cigarettes, seen among addict individuals, might also contribute to tar staining. Previous studies have shown that the proportion of alcohol disorders increases with cigarette consumption, and that daily tobacco use increases ee with the level of alcohol consumption.[25-26] Our study is the first to demonstrate an rr association between harmful alcohol use and tar staining independent of the extent of tobacco consumption. Alcohol consumption in itself could influence smoking behaviour, ev which in turn impacts on tar deposition. Nil and colleagues reported increased puff volume following consumption of 0.7 g/kg of ethanol.[27] We believe that this addictive behaviour ie and concomitant high alcohol consumption could impact tobacco cessation programs, although it has not been tested yet. w on The study has several limitations. First, many diagnoses were obtained from medical records or from patients self-reporting. Thus the study was dependent of the quality and ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com completeness of medical charts and subject to recall bias. This assessment might also cover a specific fraction of mental disorders (those who seek professional help). Second, tobacco dependence or problematic alcohol consumption were not measured with established instruments (e.g. AUDIT). “Harmful alcohol use” is not a standard definition and includes MCV which has a low specificity. Furthermore, the observers were not blinded to the allocation (case vs. control) of the patients, which could influence clinical interview. However, the results are plausible, and future studies should used standard tools to confirm them. 11 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Third, power size calculation was made for 50 pairs and only 49 could be found, because of the restrictive matching criteria. Moreover, 22% of controls reported transient tar discoloration in the past, which might have blurred the effect. However, tar deposition appears to be constant over time in the case group, and a transient finger staining could be a clinically insignificant event. Finally, our observations are limited to the inpatient hospital setting and may have to be confirmed in finger-stained patients seen outside this context. In a world of growing technology and complicated diagnosis procedure, our work highlights rp Fo the importance of clinical assessment of smokers; an important message to transmit in medical education. This costless and easy obtainable information should stress tobaccorelated disease screening and reinforce smoking counselling. Harmful alcohol use should be explored among these patients. ACKNOWLEDGEMENTS rr ee We gratefully acknowledge Sebastian Carballo, Fraser Easton and Andrew Stewardson for ev their correction of the English manuscript. w COMPETING INTERESTS ie All authors declare: no support from any organisation for the submitted work; no financial on relationships with any organisations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work. ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 12 of 42 FUNDING This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors REFERENCES: 12 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 13 of 42 BMJ Open 1. World Health Organziation. Report on the global tobacco epidemic. http://www.who.int/tobacco/global_report/2011/qanda/en/index.html, 2011. 2. Ezzati M, Lopez AD. Regional, disease specific patterns of smoking-attributable mortality in 2000. Tob Control 2004;13(4):388-95. 3. United States. Public Health Service. Office of the Surgeon General. How tobacco smoke causes disease the biology and behavioral basis for smoking-attributable disease : a report of the Surgeon General. Rockville, MD [Washington, D.C.]: U.S. Dept. of Health and Human Services, Public Health Service For sale by the Supt. of Docs., U.S. G.P.O., 2010:1 online resource (xv, 706 p.). 4. Aberle DR, Adams AM, Berg CD, Black WC, Clapp JD, Fagerstrom RM, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med 2011;365(5):395-409. 5. Solly S. Clinical lectures on paralysis. The Lancet 1856;63(1738):669-71. 6. Lange P, Schnohr P. The relationship between facial wrinkling and airflow obstruction. Int J Dermatol 1994;33(2):123-6. 7. Levine H. The yellow rounded digit: sign of the times. N Engl J Med 1968;279(12):660-1. 8. Verghese A, Krish G, Howe D, Stonecipher M. The harlequin nail. A marker for smoking cessation. Chest 1990;97(1):236-8. 9. Lawrence D, Mitrou F, Zubrick SR. Smoking and mental illness: results from population surveys in Australia and the United States. BMC Public Health 2009;9:285. 10. Kalman D, Morissette SB, George TP. Co-morbidity of smoking in patients with psychiatric and substance use disorders. Am J Addict 2005;14(2):106-23. 11. Thakurdas H. Smoking and Psychiatrc Patient. Br Med J 1963;388. 12. Hafezi M, Bohnert M, Weinmann W, Pollak S. Prevalence of nicotine consumption in drug deaths. Forensic Sci Int 2001;119(3):284-9. 13. World Health Organisation. International statistical classification of diseases and related health problems. 10 ed. Geneva, 2007. 14. Global Initiative for Chronic Obstructive Lung Disease (GOLD), Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease. , 2009. 15. The Criteria Committee of the New York Heart Association. Nomenclature and Criteria for Dagnosis of Diseases of the Heart and Great Vessels. 9 ed. Boston, Mass, 1994. 16. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4 ed. Washington, DC: American Psychiatric Association, 1994. 17. World Health Organziation. Lexicon of alcohol and drug terms published by the World Health Organization. http://www.who.int/substance_abuse/terminology/who_lexicon/en/, 2005. 18. The National Statistics Socio-economic Classification (NS-SEC rebased on the SOC2010), 2010. 19. Hankinson JL, Odencrantz JR, Fedan KB. Spirometric reference values from a sample of the general U.S. population. Am J Respir Crit Care Med 1999;159(1):179-87. 20. Courvoisier DS, Combescure C, Agoritsas T, Gayet-Ageron A, Perneger TV. Performance of logistic regression modeling: beyond the number of events per variable, the role of data structure. J Clin Epidemiol 2011;64(9):993-1000. 21. Sorensen LT, Toft B, Rygaard J, Ladelund S, Teisner B, Gottrup F. Smoking attenuates wound inflammation and proliferation while smoking cessation restores inflammation but not proliferation. Wound Repair Regen 2010;18(2):186-92. 22. Reus WF, Robson MC, Zachary L, Heggers JP. Acute effects of tobacco smoking on blood flow in the cutaneous micro-circulation. Br J Plast Surg 1984;37(2):213-5. 23. Rojanapongpun P, Drance SM. The effects of nicotine on the blood flow of the ophthalmic artery and the finger circulation. Graefes Arch Clin Exp Ophthalmol 1993;231(7):371-4. w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 13 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open 24. Wood D, Wilkes E. Project Wheat - Part 1 Cluster Profiles of U.K. Male Smokers and Their General Smoking Habits. Report No. Rd.1229-R., 1960. 25. Friedman GD, Tekawa I, Klatsky AL, Sidney S, Armstrong MA. Alcohol drinking and cigarette smoking: an exploration of the association in middle-aged men and women. Drug Alcohol Depend 1991;27(3):283-90. 26. Dawson DA. Drinking as a risk factor for sustained smoking. Drug Alcohol Depend 2000;59(3):235-49. 27. Nil R, Buzzi R, Battig K. Effects of single doses of alcohol and caffeine on cigarette smoke puffing behavior. Pharmacol Biochem Behav 1984;20(4):583-90. w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 14 of 42 14 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 15 of 42 BMJ Open Table 1 Baseline characteristics of the yellow-stained finger cases and their controls smokers. Values are numbers (percentage) unless stated otherwise. Variables Cases (n=49) Controls (n=49) P value* Matching .65 † 59 (50 - 69) 62 (50 - 69) Median (IQR) age (years) Male 32 (65) 32 (65) .99 .84 † 170 (165 - 175) 170 (165 - 177) Median (IQR) height (centimetres) ‡ Median (IQR) pack years’ smoked 50 (40 - 61) 46 (38- 58) .20 † § .60 † 3.2 (2.4 - 3.7) 3.3 (2.4 - 3.8) Median (IQR) predicted FEV1 (litres) || Diagnosis category on admission .48 15 (31) 11 (22) Cardiovascular Neurologic 7 (14) 6 (12) .99 .79 6 (12) 8 (16) Oncology Infectious disease 5 (10) 5 (10) .99 .99 5 (10) 6 (12) Traumatology Others 12 (24) 12 (24) .99 * McNemar and exact test unless stated otherwise † Paired Wilcoxon sign-rank test ‡ Number of packs smoked in a day multiplied by the number of years spent smoking or sum of the different PYs throughout life if the consumption was higher or lower for more than a year’s duration § Predicted FEV1 calculated according to the third National Health and Nutrition Examination Survey formula18 || Category of main diagnosis claimed on the exit chart FEV1: maximal forced expiratory volume in one second; PY: pack year unit; 95%CI: 95% confidence interval; IQR: interquartile range 25-75% w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 15 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Table 2 Stains characteristics in cases. Value are numbers of cases (percentage) unless stated otherwise Stains characteristics Cases N(%)* Time of stain appearance (years) 15 (31) 1-4 5-9 2 (4) 31 (65) ≥10 Suffering due to the stain 3 (6) 23 (48) Physical/chemical attempt to remove the stain Variation over time (stain size or intensity) 18 (37) 3 (2-4) Median (IQR) stains per cases Median (IQR) nails stained 2 (1-3) 1 (0-2) Median (IQR) stains on skin Median (IQR) number of fingers discoloured per cases 3 (2-4) 25 (52) First finger 45 (94) Second finger 37 (77) Third finger 1 (2) Fourth finger 0 (0) Fifth finger 1.9 (1.0-3.1) Median (IQR) total skin area stained per cases (square centimetre) * Stain location, size, and colour intensity were impossible to determine for one patient due to peripheral cyanosis at the time of examination. In another three cases, the precise size of stains present on skin (five stains) was not measured because of scant demarcation of the stain. IQR: interquartile range 25-75% w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 16 of 42 16 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Page 17 of 42 Table 3 Tobacco-related diseases and respiratory complaints. Values are numbers (percentage) unless stated otherwise Cases Controls N pairs OR(CI 95%) p value* Tobacco-related disease Any tobacco-related disease † 41 (84) 39 (80) 49 1.3 (0.4-4.1) .80 .83 0.9 (0.4-2.3) 49 26 (53) 25 (51) Vascular disease Coronary arterial disease ‡ 17 (35) 19 (39) 49 0.8 (0.3-2.1) .67 .69 0.5 (0.1-3.5) 49 6 (12) 4 (8) Strokes/TIA§ Peripheral arterial disease || 15 (31) 5 (10) 49 3.5 (1.1-14.6) .03 .13 2.2 (0.7-8.1) 47 24 (49) 30 (64) COPD FEV1/FVC<70% 24 (52) 17 (37) 46 2.2 (0.8-6.9) .11 .59 1.3 (0.4-4.7) 49 20 (41) 22 (45) Clinical diagnosis ¶ ** Smoking-related Cancer 10 (20) 7 (14) 49 1.5 (0.5-5.1) .61 Respiratory complaints Coughing 32 (65) 25 (51) 49 2.2 (0.8-6.9) .11 .28 1.8 (0.5-6.8) 49 15 (31) 19 (39) Sputum production †† ‡‡ Median (IQR) grade dyspnoea 1 (1-2) 1 (0-2) 49 .14 §§ .004 4.5 (1.5-18.3) 49 10 (20) 24 (49) Abnormal lung auscultation Median (IQR) FEV1 (litre) 1.9 (1.3-2.5) 1.8 (1.4-2.6) 46 .49 ‡‡ * McNemar exact test † At least one vascular disease, BPCO, or smoking-related carcinoma ‡ Self reporting angina pectoris, heart infarction, coronary arterial bypass graft, percutaneous angioplasty or more than 50% vessel obstruction on coronary catheterization § Stroke or a transient neurologic symptoms except traumatic, haemorrhagic, or cardio embolic event || Self reporting symptomatic arterial claudication, ankle brachial ratio less than 0.9, or chirurgical or radiological procedure for arterial insufficiency ¶ Self reporting or documented in the medical record ** Carcinoma of lung, urinary tract, or head and neck †† According to the New York Heart Association functional capacity classification ‡‡ Paired Wilcoxon sign-rank test §§ Wheezing or crackles N pairs: number of pairs used in the analysis; OR: Odds ratio; FEV1: maximal forced expiratory volume in one second; FVC: forced vital capacity; TIA: transient ischemic attack; COPD: chronic obstructive pulmonary disease; CI95: 95% confidence interval; IQR: (interquartile range 25-75%) w ie . ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open 17 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Table 4 Smoking behaviour, mental health, harmful alcohol use, and occupation categories in univariated and multivariated conditional regression model. Values are numbers (percentage) unless stated otherwise Univariated Multivariated Cases Controls OR (CI 95%) p value aOR (CI 95%) p value Fo Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Page 18 of 42 Smoking habits Median (IQR) age at beginning (years) 17 (15-20) 18 (15-20) 1.5 (1.0-2.4) * .06 2.1 (1.1-4.0) * .02 † † Median (IQR) number pack per day 1 (1-1.8) 1 (1-1.5) 3.9 (1.2-12.7) .02 8.5 (1.9-38.4) .006 Nb of brand median (IQR) 2 (1-3) 2 (2-3) 0.9 (0.7-1.2) .39 Breaks median (IQR) 1 (0-2) 2 (1-3) 0.7 (0.5-1) .03 Nb patients smoking unfiltered cigarettes 20 (41) 9 (18) 3.2 (1.2-8.7) .02 4.2 (1.1-16.0) .04 Nb patients smoking low tar cigarettes 7 (14) 17 (35) 0.3 (0.1-0.9) .03 Mental health and harmful alcohol use Harmful alcohol use § 25 (51) 10 (20) 3.5 (1.4-8.7) .007 4.6 (1.2-17.2) .02 Others psychiatric condition || 22 (45) 14 (29) 1.7 (0.8-3.7) .18 ¶ On psychotropic medication 33 (67) 20 (41) 2.4 (1.1-5.3) .02 Occupation Unemployment 17 (35) 12 (24) 1.7 (0.7-4.3) .26 * For every two years younger than 22 years old † For every ten cigarettes more than 20 ‡ For every ten years § More than fourteen drinks per week for women, more than twenty-one drinks per week for men associated with alcohol withdrawal, or documented complications || According to the medical chart and DSMIV criteria ¶ Antidepressant, anxiolytic, neuroleptic, and antiepileptic (used as mood stabilizer) drug OR (CI95%): Odds ratio (95% confidence interval); aOR: adjusted Odds ratio; IQR: (interquartile range 25-75%) rp ee rr ev iew on ly 18 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 19 of 42 BMJ Open w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 19 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open TOBACCO STAINED FINGERS: A CLUE FOR SMOKING RELATED DISEASE OR HARMFUL ALCOHOL USE? A CASE-CONTROL STUDY. Authors: During the study, except Cécile Delhumeau-Cartier*, all authors were working in rp Fo the Department of Internal Medicine, Hôpitaux Neuchâtelois, La Chaux-de-Fonds, Switzerland. Gregor John, MD (correspondence to and requests for reprints); Department of Internal medicine, Geneva University Hospitals (HUG), Gabrielle-Perret-Gentil 4, CH-1205 Geneva, ee Switzerland, Phone number: 0041 79 553 43 08, [email protected] (may be published). rr Sephora Pasche, MD; Department of Community Medicine, Primary Care and Emergency ev Medicine, Geneva University Hospitals (HUG), Geneva, Switzerland; [email protected] Nicole Rothen, MD; -Department of Internal Medicine, Bern University hospital, Bern, Switzerland; [email protected] w ie Alexia Charmoy, MD; Department of Anaesthesiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland, [email protected] on Cécile Delhumeau-Cartier*, PhD, statistician; Department of Internal Medicine, Geneva University Hospitals (HUG), Geneva, Switzerland; [email protected] ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 20 of 42 Daniel Genne, Professor; Department of Internal Medicine, Hôpitaux Neuchâtelois, La Chaux-de-Fonds, Switzerland; [email protected] Key words (MeSh) : Smoking; Alcohol Drinking; Physical examination; Pulmonary Disease, Chronic Obstructive; cardiovascular disease. Word count: Abstract: 256, Article: 2496 1 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 21 of 42 BMJ Open ABSTRACT Objective: Tobacco stain on fingers is frequent. However, there is scarce description of this clinical sign. We aimed to explore tobacco stain on fingers as a marker of tobacco related disease independent of cumulative tobacco exposure, and find behavioural and environmental characteristics associated with those stains. Design: Case-control study rp Fo Setting: A Swiss community hospital of 180 beds. Participants: 49 adults presenting tobacco-tars staining on fingers were matched to 49 control smokers by age, gender, height, and pack-year. Outcome measures: Documented smoking related carcinoma, ischemic heart disease, ee peripheral arterial disease, stroke, and chronic obstructive pulmonary disease (COPD) also determined by lung function, were compared between groups. Association between harmful rr alcohol use, mental disorders, or unemployment, and tar-staining was adjusted for smoking behaviour through conditional logistic regression. ev Results: Overall cigarette related disease was high in the case group (84%), and symptomatic peripheral arterial disease was more frequent compared to controls (OR 3.5, ie CI95% 1.1-14.6). Smoking-related carcinoma, ischemic heart disease, stroke, and COPD w were not statistically different to control smokers. Harmful alcohol use was strongly associated with stains and this association persists after adjustment for smoking unfiltered on cigarettes, smoking more than one pack of cigarette in a day, and age at smoking onset ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com (adjusted OR 4.6, CI95% 1.2-17.2). Mental disorders and unemployment were not statistically significant. Conclusions: Patients with tobacco-tar stained fingers frequently have cigarette related disease, however statistically not more than control smokers matched for YP, except for symptomatic peripheral arterial disease. This study suggests a link between stained fingers and addictive behaviour or concomitant high alcohol consumption. 2 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open ARTICLE SUMMARY Article focus • Identification of smokers at high risk of smoking related disease could impact their management. • A deeper puff could result in higher tar deposition on skin and greater inhalation of tobacco, putting the lung and distant organs at increased health hazard • rp Fo Apart from cigarette characteristics, behavioural and environmental factors may be important in stain development. Key messages • Tobacco related diseases (defined as smoking related carcinoma, ischemic heart ee disease, peripheral arterial disease, stroke, or chronic obstructive pulmonary disease) are frequent (84%) among patients with tobacco-tar stained fingers. • rr However, tobacco-tar stained fingers seem to identify high-risk smokers due to the ev tobacco exposure, rather than a specific increased susceptibility • The study suggests a link between this tar-stained fingers and addictive behaviour or concomitant high alcohol consumption. • w Strengths and limitations of this study ie This case-control study explores an easily identifiable and frequent clinical sign on among smokers and appreciates the additional risk for health due to tar deposition (influenced by puffing or cigarettes characteristics) not included in the usual measure of tobacco exposure (PY). • ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 22 of 42 Diagnoses were obtained from medical records or from patients self-reporting, subject to recall bias. Problematic alcohol consumption was not measured with established instruments (e.g. AUDIT). The sample size was small. This study included only hospital population. 3 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 23 of 42 BMJ Open INTRODUCTION "The yellow finger stain is an emblem of deeper degradation and enslavement than the ball and chain." Henry Ford, The Case Against the Little White Slaver (Detroit: 1914) Tobacco use is the leading cause of preventable death around the world. The 2011 World rp Fo Health Organization report on the global tobacco epidemic predicted that if current trends persist, more than eight million people worldwide will die from tobacco related disease each year by 2030.[1] Although cigarette smoking is by far the most common risk factor for chronic ee obstructive pulmonary disease (COPD), is strongly associated with cardiovascular disease, and is responsible for 30% of all cancer deaths, additional factors are involved in determining rr each individual’s susceptibility to tobacco related disease.[2-3] Identifying smokers at higher risk of developing disease could improve their management and screening programs.[4] ev Smoking has been linked to many skin conditions for more than 150 years and evidence ie exist that skin involvement might be a conspicuous marker of other tobacco related w disease.[5] For example, smoking related wrinkles have been associated with a decrease in lung function independent of tobacco exposure.[6] The “yellow rounded digit” and “Harlequin on nail” signs are two other simple clinical signs which aid the diagnosis of health conditions.[7- ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 8] The former, characterised by fingers that are both tobacco-stained and clubbed, raises suspicion of lung carcinoma. The latter is seen after an acute illness that causes cessation of cigarette consumption resulting in a bi-colour nail (the distal end is cigarette stained contrasting the newly growing proximal part). We hypothesised that tar deposition itself (figure 1) could be a marker of tobacco related disease independent of cumulative tobacco exposure. A deeper puff could result in higher tar deposition on skin and greater inhalation of tobacco, putting the lung and distant organs at increased health hazard. 4 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Tobacco-stains on fingers are commonly seen among smokers but there is scarce description of this phenomenon. Apart from cigarette characteristics, behavioural and environmental factors may be important in stain development. Epidemiologic studies worldwide show higher rate of smoking among people suffering from mental or substance use disorders.[9-10] Yellow stained fingers often observed in psychiatric units and among young drug users (autopsy series) supports a possible association between those conditions and tar deposition.[11-12] rp Fo We conducted the present study to determine whether tar deposit is an independent marker of tobacco related disease and to identify factors associated with stain development, such as ee alcohol consumption, psychiatric conditions, unemployment, and smoking habits. METHODS ev Study design and population rr We performed a case-control study between March 2006 and January 2010 in a 180-bed ie community hospital in La Chaux-de-Fonds, Switzerland. Eligible patients were adult current smokers admitted to the departments of internal medicine or surgery, or the intensive care w unit, irrespective of diagnosis or cause of admission. We excluded patients unable to provide on informed consent, those post thoracic surgery or suffering from an ear–nose–throat (ENT) conditions which could prevent lung function testing, patients receiving palliative care, and ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 24 of 42 pregnant women. Cases were defined by presence of tobacco stains on their fingers, and were reported to the study group by the medical team or identified by the group through frequent screening. They were included consecutively to avoid selection bias. Controls were selected randomly from the same population, to fulfil the matching criteria. All participants provided written informed consent. Institutional Review Board approved the study. Measures and outcomes of interest 5 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 25 of 42 BMJ Open Four physicians dedicated to the study collected all information. The main investigator checked data accuracy using the study information and medical charts. A single thirty-minute standard interview was performed for each participant to obtain a medical history, a physical exam, and to perform pulmonary function tests. Investigations were performed at least one month after an exacerbation of a chronic pulmonary condition, pneumonia, or acute heart failure. Forced expiratory volume in one second (FEV1) and the forced vital capacity (FVC) were assessed using Microloop spirometer (Micro Medical Limited, England). rp Fo Tobacco-related disease A history of tobacco-related disease – ischemic stroke (haemorrhagic or cardio-embolic events excluded), coronary heart disease (CHD), peripheral arterial disease (PAD), tobaccorelated carcinoma (lung, urinary tract, or ENT), and COPD- was obtained from the patient’s ee interview and from past and current medical records, classified according to the International rr Statistical Classification of Diseases, tenth revision (ICD-10).[13] COPD was also assessed on lung function, when FEV1/FVC was less than 70%.[14] We defined coronary heart disease ev (CHD) as a history of angina pectoris, myocardial infarction, coronary arterial bypass graft, arterial angioplasty, or known vessel obstruction of 50% or more. Leg pain associated with ie ankle brachial ratio index less than 0.9 or a procedure for arterial insufficiency defined a w peripheral arterial disease (PAD). We recorded coughing, sputum production, and the degree of dyspnea according to the New York Heart Association classification (NYHA).[15] ly Factors for stains development: on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com We documented any mental disorders diagnosed according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria and antidepressant, benzodiazepine, neuroleptic, or mood stabilizer use.[16] We considered harmful alcohol use when high alcohol intake –more than fourteen standard drinks per week for women and more than twenty-one standard drinks per week for men (140g and 210g of alcohol respectively)- was associated with documented withdrawal, medical consequences (neurologic, cardiac, 6 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open hepatic, or pancreatic), or erythrocyte macrocytosis (mean corpuscular volume greater than 98 fl) not otherwise explained.[17] Occupations were classified according to the six-class version of the National Statistics Socio-Economic Classification.[18] Previous occupation was considered for retired individuals. Smoking habits reviewed were: age at onset, number of packets smoked per day, unfiltered, or low tar cigarettes, and attempts at smoking cessation. Patients were questioned on the number of years the stains have been present, their rp Fo tendency to extend, their impact on everyday life, and attempts to make them disappear. We recorded the number and location of stains for each patient as well as the surface area in centimetres squared of stain located on finger skin only. The intensity of all stains was graded using a standardised visual scale from one to five depending on the colour (pale yellow to intense brown). ev rr Statistical analysis ee We paired one control for every case, and matched them individually by age, gender, height, and pack-years smoked (PY). Pairs were matched closely with up to ten percent difference ie for each continuous variable. We then compared the predicted value of FEV1 (according to w height, age, and gender) of each pair to ensure a difference of <10%.[19] The PY was calculated as the number of packs smoked in a day multiplied by the number of years spent on smoking. When the consumption was irregular from day to day we used the mean of the extremes as an estimate of the number of packs smoked daily. If the consumption was ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 26 of 42 higher or lower for more than a year’s duration, the total cumulative PY was calculated as the sum of the different PYs throughout life. We calculated that 50 participants in each group would allow us to detect a threefold increase of tobacco related disease in the cases group (odds ratio), using McNemar test with a two-sided alpha of 5% and a power of 80%, if at least 30% of pairs are discordant. To compare groups, we used McNemar test for binary variables and paired Wilcoxon test for 7 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 27 of 42 BMJ Open continuous variables. Among the case group, we used Spearman rank correlation to test for an association between measured FEV1 and stain characteristics. Conditional logistic regression was used to assess the association between cigarette staining and mental health condition, psychotropic medications, harmful alcohol use, occupational categories, and smoking behaviours. We built a parsimonious multivariate model, guided by the analyst, entering each potential variable one by one, starting with those strongly associated and clinically relevant, and keeping only statistically significant and mutually rp Fo adjusted variables in the final model. With about 50 events (cases) and a requested number of 10-15 events per variable we expected a maximum of 4-5 variables in the final model.[20] We performed post hoc sub-analyses excluding pairs in which controls notified finger/nail ee stains in the past. Since those analyses showed similar results, only results of the initial analyses are shown. ev rr Analyses were performed on cases and controls with complete documented information. Data analyses were perform by using STATA 10.1 (StataCorp LP, Texas, USA). This study ie received no external funding source and volunteers received no financial reward. w RESULTS Participants: ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Between March 2006 and December 2007, 4520 patients were admitted to the hospital, of which 1127 were current smokers (25%). Among those current smokers, 63 (6%) presented one or more tar staining on the hand. Nine refused to participate and five could not be matched, resulting into 49 cases. The corresponding 49 controls were included between February 2007 and January 2010. All participants were Caucasians (Table 1). 8 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open For one participant stain characteristics were impossible to determine due to a peripheral cyanosis at the time of examination. The 48 other cases possessed a total of 153 stains; 64% on nail and 36% on finger skin (Table 2). Among the controls, eleven (22%) reported the presence of at least one stain on fingers within their lifetime but not at the time of the study. Tobacco related disease, and lung function test: Although there was a slight increase in vascular disease, COPD, and smoking related cancer rp Fo in the case group, the difference was not statistically significant (Table 3). Peripheral arterial disease was more prevalent among the case group with 14/49 (29%) complaining of claudication and 12/49 (24%) having undergone revascularization procedure compared to 5/49 (10%; p=0.049) and 2/49 (4%; p=0.006) respectively in the control group. rr ee Lung function tests were not available for three controls. Measured FEV1 was not statistically different between groups. Thirteen cases (26%) and 11/46 (24%) controls had less than ev 50% of expected FEV1. Stain number (r: 0.13, p=0.39), mean size (r: 0.24, p=0.25), and median colour intensity (r: 0.22, p=0.13) had no influence on measured FEV1 among cases. Factors associated with tar staining: w ie Smoking more than one pack of cigarettes per day, smoking unfiltered cigarettes, having on more cigarette breaks, harmful alcohol use, or being on psychotropic medication were all associated with higher risk of tar staining in univariate analyses (Table 4). Use of low tar ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 28 of 42 content cigarettes was less frequent among tobacco stain participants. In a multivariate analysis, four factors remained significantly associated with stain: smoking more than one pack per day, smoking unfiltered cigarettes, age at onset, and harmful alcohol use. Adding more variables produced artificially high OR due to insufficient events-pervariable. These four factors accounted for 41% of variance (pseudo-R2) in the presence of stains. 9 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Page 29 of 42 DISCUSSION Our case-control study explores an easily identifiable and frequent clinical sign among smokers. Tobacco related diseases (defined as smoking related carcinoma, ischemic heart disease, peripheral arterial disease, stroke, and chronic obstructive pulmonary disease) are frequent (84%) among patients with tobacco-tar stained fingers. Furthermore, this clinical sign is linked to harmful alcohol use. As far as we know this is the first description of this particular category of smokers. rp Fo The design of the study appreciates the additional risk for health due to tar deposition not included in the usual measure of tobacco exposure (PY). Stain may result from local pigment ee deposition secondary to high tar concentration in the skin-cigarette interface (influenced by puffing or cigarettes characteristics), but higher concentration of nicotine (and other rr substances) smoked could affect stain removal by impaired skin repair. [21] Similarly, nicotine has been shown to reduce blood flow in fingers and increase systemic blood ev pressure, a mechanism that could rationally explain the association of impaired stain removal and peripheral arterial disease. [22, 23] w ie Yet the high incidence of COPD, overall cardiovascular disease, and tobacco-related carcinomas are not independently related to tar deposition. Besides, similar lung function on between case and control groups and the absence of relationship between FEV1 and stain characteristics among cases are consistent with a lack of association between yellow fingers ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open and obstructive lung disease. We believe that yellow staining identifies high-risk smokers due to the tobacco exposure (PY), rather than a specific increased susceptibility (e.g. puffing characteristics). Lack of an association with investigated tobacco related illnesses other than symptomatic peripheral arterial disease, could however arise from insufficient power of the study. 10 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Four variables mutually adjusted – smoking more than one pack of cigarette in a day or unfiltered cigarettes, age at smoking onset, and harmful alcohol use – could explain a substantial part of stain development, even in individuals matched for characteristics that are probably linked to stains (pack-year, age, and gender). Our results suggest that staining is influenced by the characteristics of cigarettes smoked and smoker’s behaviour. Indeed, finger stained smokers seem to present a more severe addictive behaviour (high proportion of harmful alcohol use, early age at smoking onset, high number of cigarettes smoked per day, and few cigarette breaks). An industry-funded study concluded that psychological and rp Fo personality constructs were positively associated with depth of inhalation.[24] Apart from puffing characteristics, smoking the entirety of cigarettes, seen among addict individuals, might also contribute to tar staining. Previous studies have shown that the proportion of alcohol disorders increases with cigarette consumption, and that daily tobacco use increases ee with the level of alcohol consumption.[25-26] Our study is the first to demonstrate an rr association between harmful alcohol use and tar staining independent of the extent of tobacco consumption. Alcohol consumption in itself could influence smoking behaviour, ev which in turn impacts on tar deposition. Nil and colleagues reported increased puff volume following consumption of 0.7 g/kg of ethanol.[27] We believe that this addictive behaviour ie and concomitant high alcohol consumption could impact tobacco cessation programs, although it has not been tested yet. w on The study has several limitations. First, many diagnoses were obtained from medical records or from patients self-reporting. Thus the study was dependent of the quality and ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 30 of 42 completeness of medical charts and subject to recall bias. This assessment might also cover a specific fraction of mental disorders (those who seek professional help). Second, tobacco dependence or problematic alcohol consumption were not measured with established instruments (e.g. AUDIT). “Harmful alcohol use” is not a standard definition and includes MCV which has a low specificity. Furthermore, the observers were not blinded to the allocation (case vs. control) of the patients, which could influence clinical interview. However, the results are plausible, and future studies should used standard tools to confirm them. 11 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 31 of 42 BMJ Open Third, power size calculation was made for 50 pairs and only 49 could be found, because of the restrictive matching criteria. Moreover, 22% of controls reported transient tar discoloration in the past, which might have blurred the effect. However, tar deposition appears to be constant over time in the case group, and a transient finger staining could be a clinically insignificant event. Finally, our observations are limited to the inpatient hospital setting and may have to be confirmed in finger-stained patients seen outside this context. In a world of growing technology and complicated diagnosis procedure, our work highlights rp Fo the importance of clinical assessment of smokers; an important message to transmit in medical education. This costless and easy obtainable information should stress tobaccorelated disease screening and reinforce smoking counselling. Harmful alcohol use should be explored among these patients. ACKNOWLEDGEMENTS rr ee We gratefully acknowledge Sebastian Carballo, Fraser Easton and Andrew Stewardson for ev their correction of the English manuscript. w COMPETING INTERESTS ie All authors declare: no support from any organisation for the submitted work; no financial on relationships with any organisations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work. ly 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com FUNDING This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors REFERENCES: 12 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open 1. World Health Organziation. Report on the global tobacco epidemic. http://www.who.int/tobacco/global_report/2011/qanda/en/index.html, 2011. 2. Ezzati M, Lopez AD. Regional, disease specific patterns of smoking-attributable mortality in 2000. Tob Control 2004;13(4):388-95. 3. United States. Public Health Service. Office of the Surgeon General. How tobacco smoke causes disease the biology and behavioral basis for smoking-attributable disease : a report of the Surgeon General. Rockville, MD [Washington, D.C.]: U.S. Dept. of Health and Human Services, Public Health Service For sale by the Supt. of Docs., U.S. G.P.O., 2010:1 online resource (xv, 706 p.). 4. Aberle DR, Adams AM, Berg CD, Black WC, Clapp JD, Fagerstrom RM, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med 2011;365(5):395-409. 5. Solly S. Clinical lectures on paralysis. The Lancet 1856;63(1738):669-71. 6. Lange P, Schnohr P. The relationship between facial wrinkling and airflow obstruction. Int J Dermatol 1994;33(2):123-6. 7. Levine H. The yellow rounded digit: sign of the times. N Engl J Med 1968;279(12):660-1. 8. Verghese A, Krish G, Howe D, Stonecipher M. The harlequin nail. A marker for smoking cessation. Chest 1990;97(1):236-8. 9. Lawrence D, Mitrou F, Zubrick SR. Smoking and mental illness: results from population surveys in Australia and the United States. BMC Public Health 2009;9:285. 10. Kalman D, Morissette SB, George TP. Co-morbidity of smoking in patients with psychiatric and substance use disorders. Am J Addict 2005;14(2):106-23. 11. Thakurdas H. Smoking and Psychiatrc Patient. Br Med J 1963;388. 12. Hafezi M, Bohnert M, Weinmann W, Pollak S. Prevalence of nicotine consumption in drug deaths. Forensic Sci Int 2001;119(3):284-9. 13. World Health Organisation. International statistical classification of diseases and related health problems. 10 ed. Geneva, 2007. 14. Global Initiative for Chronic Obstructive Lung Disease (GOLD), Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease. , 2009. 15. The Criteria Committee of the New York Heart Association. Nomenclature and Criteria for Dagnosis of Diseases of the Heart and Great Vessels. 9 ed. Boston, Mass, 1994. 16. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4 ed. Washington, DC: American Psychiatric Association, 1994. 17. World Health Organziation. Lexicon of alcohol and drug terms published by the World Health Organization. http://www.who.int/substance_abuse/terminology/who_lexicon/en/, 2005. 18. The National Statistics Socio-economic Classification (NS-SEC rebased on the SOC2010), 2010. 19. Hankinson JL, Odencrantz JR, Fedan KB. Spirometric reference values from a sample of the general U.S. population. Am J Respir Crit Care Med 1999;159(1):179-87. 20. Courvoisier DS, Combescure C, Agoritsas T, Gayet-Ageron A, Perneger TV. Performance of logistic regression modeling: beyond the number of events per variable, the role of data structure. J Clin Epidemiol 2011;64(9):993-1000. 21. Sorensen LT, Toft B, Rygaard J, Ladelund S, Teisner B, Gottrup F. Smoking attenuates wound inflammation and proliferation while smoking cessation restores inflammation but not proliferation. Wound Repair Regen 2010;18(2):186-92. 22. Reus WF, Robson MC, Zachary L, Heggers JP. Acute effects of tobacco smoking on blood flow in the cutaneous micro-circulation. Br J Plast Surg 1984;37(2):213-5. 23. Rojanapongpun P, Drance SM. The effects of nicotine on the blood flow of the ophthalmic artery and the finger circulation. Graefes Arch Clin Exp Ophthalmol 1993;231(7):371-4. w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 32 of 42 13 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 33 of 42 BMJ Open 24. Wood D, Wilkes E. Project Wheat - Part 1 Cluster Profiles of U.K. Male Smokers and Their General Smoking Habits. Report No. Rd.1229-R., 1960. 25. Friedman GD, Tekawa I, Klatsky AL, Sidney S, Armstrong MA. Alcohol drinking and cigarette smoking: an exploration of the association in middle-aged men and women. Drug Alcohol Depend 1991;27(3):283-90. 26. Dawson DA. Drinking as a risk factor for sustained smoking. Drug Alcohol Depend 2000;59(3):235-49. 27. Nil R, Buzzi R, Battig K. Effects of single doses of alcohol and caffeine on cigarette smoke puffing behavior. Pharmacol Biochem Behav 1984;20(4):583-90. w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 14 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Table 1 Baseline characteristics of the yellow-stained finger cases and their controls smokers. Values are numbers (percentage) unless stated otherwise. Variables Cases (n=49) Controls (n=49) P value* Matching .65 † 59 (50 - 69) 62 (50 - 69) Median (IQR) age (years) Male 32 (65) 32 (65) .99 .84 † 170 (165 - 175) 170 (165 - 177) Median (IQR) height (centimetres) ‡ Median (IQR) pack years’ smoked 50 (40 - 61) 46 (38- 58) .20 † § .60 † 3.2 (2.4 - 3.7) 3.3 (2.4 - 3.8) Median (IQR) predicted FEV1 (litres) || Diagnosis category on admission .48 15 (31) 11 (22) Cardiovascular Neurologic 7 (14) 6 (12) .99 .79 6 (12) 8 (16) Oncology Infectious disease 5 (10) 5 (10) .99 .99 5 (10) 6 (12) Traumatology Others 12 (24) 12 (24) .99 * McNemar and exact test unless stated otherwise † Paired Wilcoxon sign-rank test ‡ Number of packs smoked in a day multiplied by the number of years spent smoking or sum of the different PYs throughout life if the consumption was higher or lower for more than a year’s duration § Predicted FEV1 calculated according to the third National Health and Nutrition Examination Survey formula18 || Category of main diagnosis claimed on the exit chart FEV1: maximal forced expiratory volume in one second; PY: pack year unit; 95%CI: 95% confidence interval; IQR: interquartile range 25-75% w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 34 of 42 15 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 35 of 42 BMJ Open Table 2 Stains characteristics in cases. Value are numbers of cases (percentage) unless stated otherwise Stains characteristics Cases N(%)* Time of stain appearance (years) 15 (31) 1-4 5-9 2 (4) 31 (65) ≥10 Suffering due to the stain 3 (6) 23 (48) Physical/chemical attempt to remove the stain Variation over time (stain size or intensity) 18 (37) 3 (2-4) Median (IQR) stains per cases Median (IQR) nails stained 2 (1-3) 1 (0-2) Median (IQR) stains on skin Median (IQR) number of fingers discoloured per cases 3 (2-4) 25 (52) First finger 45 (94) Second finger 37 (77) Third finger 1 (2) Fourth finger 0 (0) Fifth finger 1.9 (1.0-3.1) Median (IQR) total skin area stained per cases (square centimetre) * Stain location, size, and colour intensity were impossible to determine for one patient due to peripheral cyanosis at the time of examination. In another three cases, the precise size of stains present on skin (five stains) was not measured because of scant demarcation of the stain. IQR: interquartile range 25-75% w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 16 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open Table 3 Tobacco-related diseases and respiratory complaints. Values are numbers (percentage) unless stated otherwise Cases Controls N pairs OR(CI 95%) p value* Tobacco-related disease Any tobacco-related disease † 41 (84) 39 (80) 49 1.3 (0.4-4.1) .80 .83 0.9 (0.4-2.3) 49 26 (53) 25 (51) Vascular disease Coronary arterial disease ‡ 17 (35) 19 (39) 49 0.8 (0.3-2.1) .67 .69 0.5 (0.1-3.5) 49 6 (12) 4 (8) Strokes/TIA§ Peripheral arterial disease || 15 (31) 5 (10) 49 3.5 (1.1-14.6) .03 .13 2.2 (0.7-8.1) 47 24 (49) 30 (64) COPD FEV1/FVC<70% 24 (52) 17 (37) 46 2.2 (0.8-6.9) .11 .59 1.3 (0.4-4.7) 49 20 (41) 22 (45) Clinical diagnosis ¶ ** Smoking-related Cancer 10 (20) 7 (14) 49 1.5 (0.5-5.1) .61 Respiratory complaints Coughing 32 (65) 25 (51) 49 2.2 (0.8-6.9) .11 .28 1.8 (0.5-6.8) 49 15 (31) 19 (39) Sputum production †† ‡‡ Median (IQR) grade dyspnoea 1 (1-2) 1 (0-2) 49 .14 §§ .004 4.5 (1.5-18.3) 49 10 (20) 24 (49) Abnormal lung auscultation Median (IQR) FEV1 (litre) 1.9 (1.3-2.5) 1.8 (1.4-2.6) 46 .49 ‡‡ * McNemar exact test † At least one vascular disease, BPCO, or smoking-related carcinoma ‡ Self reporting angina pectoris, heart infarction, coronary arterial bypass graft, percutaneous angioplasty or more than 50% vessel obstruction on coronary catheterization § Stroke or a transient neurologic symptoms except traumatic, haemorrhagic, or cardio embolic event || Self reporting symptomatic arterial claudication, ankle brachial ratio less than 0.9, or chirurgical or radiological procedure for arterial insufficiency ¶ Self reporting or documented in the medical record ** Carcinoma of lung, urinary tract, or head and neck †† According to the New York Heart Association functional capacity classification ‡‡ Paired Wilcoxon sign-rank test §§ Wheezing or crackles N pairs: number of pairs used in the analysis; OR: Odds ratio; FEV1: maximal forced expiratory volume in one second; FVC: forced vital capacity; TIA: transient ischemic attack; COPD: chronic obstructive pulmonary disease; CI95: 95% confidence interval; IQR: (interquartile range 25-75%) w ie . ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 36 of 42 17 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 37 of 42 Table 4 Smoking behaviour, mental health, harmful alcohol use, and occupation categories in univariated and multivariated conditional regression model. Values are numbers (percentage) unless stated otherwise Univariated Multivariated Cases Controls OR (CI 95%) p value aOR (CI 95%) p value Fo Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 BMJ Open Smoking habits Median (IQR) age at beginning (years) 17 (15-20) 18 (15-20) 1.5 (1.0-2.4) * .06 2.1 (1.1-4.0) * .02 † † Median (IQR) number pack per day 1 (1-1.8) 1 (1-1.5) 3.9 (1.2-12.7) .02 8.5 (1.9-38.4) .006 Nb of brand median (IQR) 2 (1-3) 2 (2-3) 0.9 (0.7-1.2) .39 Breaks median (IQR) 1 (0-2) 2 (1-3) 0.7 (0.5-1) .03 Nb patients smoking unfiltered cigarettes 20 (41) 9 (18) 3.2 (1.2-8.7) .02 4.2 (1.1-16.0) .04 Nb patients smoking low tar cigarettes 7 (14) 17 (35) 0.3 (0.1-0.9) .03 Mental health and harmful alcohol use Harmful alcohol use § 25 (51) 10 (20) 3.5 (1.4-8.7) .007 4.6 (1.2-17.2) .02 Others psychiatric condition || 22 (45) 14 (29) 1.7 (0.8-3.7) .18 ¶ On psychotropic medication 33 (67) 20 (41) 2.4 (1.1-5.3) .02 Occupation Unemployment 17 (35) 12 (24) 1.7 (0.7-4.3) .26 * For every two years younger than 22 years old † For every ten cigarettes more than 20 ‡ For every ten years § More than fourteen drinks per week for women, more than twenty-one drinks per week for men associated with alcohol withdrawal, or documented complications || According to the medical chart and DSMIV criteria ¶ Antidepressant, anxiolytic, neuroleptic, and antiepileptic (used as mood stabilizer) drug OR (CI95%): Odds ratio (95% confidence interval); aOR: adjusted Odds ratio; IQR: (interquartile range 25-75%) rp ee rr ev iew on ly 18 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com BMJ Open w ie ev rr ee rp Fo ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 38 of 42 19 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 39 of 42 BMJ Open ie ev rr ee rp Fo Tar staining seen in a 70 years old men smoker (80PY). 626x534mm (72 x 72 DPI) w ly on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open STROBE 2007 (v4) Statement—Checklist of items that should be included in reports of case-control studies Section/Topic Title and abstract Item # 1 Recommendation Reported on page # (a) Indicate the study’s design with a commonly used term in the title or the abstract 1 Fo rp (b) Provide in the abstract an informative and balanced summary of what was done and what was found Introduction ee 2 Background/rationale 2 Explain the scientific background and rationale for the investigation being reported 4,5 Objectives 3 State specific objectives, including any prespecified hypotheses 5 Study design 4 Present key elements of study design early in the paper Setting 5 Describe the setting, locations, and relevant dates, including periods of recruitment, exposure, follow-up, and data collection 5-7 Participants 6 (a) Give the eligibility criteria, and the sources and methods of case ascertainment and control selection. Give the rationale for 5 rr Methods the choice of cases and controls Variables 7 5 ev iew (b) For matched studies, give matching criteria and the number of controls per case 7 Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if 6,7 applicable on Data sources/ measurement 8* For each variable of interest, give sources of data and details of methods of assessment (measurement). Describe comparability of assessment methods if there is more than one group Bias 9 Describe any efforts to address potential sources of bias ly 6,7 6 Study size 10 Explain how the study size was arrived at Quantitative variables 11 Explain how quantitative variables were handled in the analyses. If applicable, describe which groupings were chosen and why 7,8 7 Statistical methods 12 (a) Describe all statistical methods, including those used to control for confounding 7,8 (b) Describe any methods used to examine subgroups and interactions 8 (c) Explain how missing data were addressed 8 (d) If applicable, explain how matching of cases and controls was addressed 7 (e) Describe any sensitivity analyses 8 1 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Page 40 of 42 Page 41 of 42 Results Participants 13* (a) Report numbers of individuals at each stage of study—eg numbers potentially eligible, examined for eligibility, confirmed 8 eligible, included in the study, completing follow-up, and analysed Descriptive data 14* Fo (b) Give reasons for non-participation at each stage 8 (c) Consider use of a flow diagram - rp (a) Give characteristics of study participants (eg demographic, clinical, social) and information on exposures and potential Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 BMJ Open 8, 15-18 confounders (b) Indicate number of participants with missing data for each variable of interest 17 ee Outcome data 15* Report numbers in each exposure category, or summary measures of exposure 15-18 Main results 16 (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (eg, 95% confidence interval). Make clear which confounders were adjusted for and why they were included 8-9, 15-18 (b) Report category boundaries when continuous variables were categorized 8-9, 15-18 (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period - Report other analyses done—eg analyses of subgroups and interactions, and sensitivity analyses 7 Other analyses 17 rr ev Discussion iew Key results 18 Summarise key results with reference to study objectives Limitations 19 Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias 11 Interpretation 20 Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of analyses, results from similar 11 studies, and other relevant evidence Generalisability on ly 21 Discuss the generalisability (external validity) of the study results 22 Give the source of funding and the role of the funders for the present study and, if applicable, for the original study on which the present article is based Other information Funding 10 11 12 *Give information separately for cases and controls in case-control studies and, if applicable, for exposed and unexposed groups in cohort and cross-sectional studies. 2 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open Note: An Explanation and Elaboration article discusses each checklist item and gives methodological background and published examples of transparent reporting. The STROBE checklist is best used in conjunction with this article (freely available on the Web sites of PLoS Medicine at http://www.plosmedicine.org/, Annals of Internal Medicine at http://www.annals.org/, and Epidemiology at http://www.epidem.com/). Information on the STROBE Initiative is available at www.strobe-statement.org. Fo Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Page 42 of 42 rp ee rr ev iew on ly 3 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Downloaded from http://bmjopen.bmj.com/ on October 18, 2016 - Published by group.bmj.com Tobacco-stained fingers: a clue for smoking-related disease or harmful alcohol use? A case−control study Gregor John, Sephora Pasche, Nicole Rothen, Alexia Charmoy, Cécile Delhumeau-Cartier and Daniel Genné BMJ Open 2013 3: doi: 10.1136/bmjopen-2013-003304 Updated information and services can be found at: http://bmjopen.bmj.com/content/3/11/e003304 These include: References This article cites 18 articles, 2 of which you can access for free at: http://bmjopen.bmj.com/content/3/11/e003304#BIBL Open Access This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/3.0/ Email alerting service Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article. 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