Technical Report PDF

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
Public Health Information and Research Branch (PHIRB)
Northern Ireland
Drug Prevalence Survey
2010/2011
Technical Report
November 2011

2

Contents
1.
1.1.
1.2.
2.
2.1.
2.2.
3.
3.1.
3.2.
3.3.
4.
4.1.
4.2.
4.3.
4.4.
5.
5.1.
5.2.
6.
6.1.
6.2.
6.3.
A.
B.
C.
D.
E.
F.
Introduction………………………………………………………....
5
Background
Research Objectives
5
6
Questionnaire Design…………………………...........................
7
Questionnaire Development
Questionnaire Testing
7
7
Survey Design.……………………………………………………...
8
Target Population
Selection of sample
Administration of Questionnaire
8
8
9
Fieldwork….……………………………………….........................
11
Fieldwork Period
Response Rate
Non-response and ineligibles
Representativeness of the achieved sample
11
11
11
12
Weighting..……………………………………………....................
14
Weighting
Calculation of NI and HSCT Weights
14
14
Statistical Methods...………………………………………...........
17
Design Effects and Confidence Intervals
Statistical Reliability and Sampling Tolerances
Statistical Significance: Comparisons between 2002/03, 2006/07 and2010/11
17
17
17
Appendices………………………………………………….………
18
Questionnaire
Show cards
Interviewer Instructions
Advance Letter to Households
Parental Permission Form
Design Effects and Confidence Intervals: Julia Sevtsenko.
19
73
142
159
163
162
3
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4

1. Introduction
This report provides details of the methodology used in the third Drug
Prevalence Survey in Northern Ireland. A separate report is available for the
concurrent survey that was carried out in Ireland.
1.1
Background
The Drug Prevalence Survey 2010/11 in Northern Ireland and Ireland was jointly
commissioned by the Public Health Information and Research Branch (PHIRB) within
the Department of Health, Social Services and Public Safety (DHSSPS) in Northern
Ireland and the National Advisory Committee on Drugs (NACD) in Ireland. The
Central Survey Unit (CSU) of the Northern Ireland Statistics and Research Agency
(NISRA) conducted the survey in Northern Ireland on behalf of PHIRB. This was the
third time this survey had been carried out in both Northern Ireland and Ireland. The
previous surveys were conducted in 2002/03 and 2006/07.
The extent and pattern of drug use in the general population is one of the five key
indicators produced by the EMCDDA, the European Monitoring Centre for Drugs and
Drug Addiction (www.emcdda.org), and adopted by EU Member States. The survey
was carried out in accordance with EMCDDA guidelines “Handbook for Surveys on
Drug Use Among the General Population.” Consequently, face-to-face interviews
were conducted with 15-64 year olds using a pre-prepared questionnaire on drug
use.
Research Advisory Group
A Research Advisory Group (RAG) was formed to ensure the survey was carried out
to the EMCDDA standard. Membership of the RAG comprised of the following
representatives, mainly from PHIRB and the NACD:
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







Mr Kieron Moore (PHIRB)
Ms Moira McKee (PHIRB, until February 2011)
Ms Caroline Hickey (PHIRB)
Dr Des Corrigan (NASD)
Ms Susan Scally, (NACD, until December 2010)
Dr Justine Horgan (NACD)
Ms Joan O‟Flynn (NACD)
Ms Deirdre Mongan (HRB)
Dr Jean Long (HRB)
Ms Marion Rackard (HSE)
Ms Dairearca Ní Néill (Drugs Policy Unit, Department of Health)
5

1.2
Research Objectives
The key objective of the research was to provide robust estimates of the prevalence
of drug use (licit and illicit) in the population of Northern Ireland (and Ireland) and
allow comparison between the results of the first and second surveys carried out in
2002/03 and 2006/07. The findings of the 2010/11 survey will also contribute towards
one of the EMCDDA‟s five key indicators on drug use.
The questionnaire and methodology used in the survey were based on the guidelines
produced by the EMCDDA and the main focus was to obtain prevalence rates for key
illegal drugs, such as cannabis, ecstasy, LSD etc, on a lifetime (ever used), last year
(recent use) and last month (current use) basis. Similar prevalence rates would also
be calculated for alcohol, tobacco and other drugs (e.g. tranquillisers). The collection
of demographic information (e.g. age, gender) would allow analysis of the findings by
different subgroups.
In order to meet the objectives of the research in Northern Ireland, 2,500 interviews
were required to be completed with respondents across the five Health and Social
Care Trust (HSCT) areas: Belfast (BHSCT), South Eastern (SEHSCT), Northern
(NHSCT), Southern (SHSCT) and Western (WHSCT).
6

2. Questionnaire Design
2.1
Questionnaire Development
The questionnaire used in the 2010/11 survey was broadly similar to those used in
2002/03 and 2006/07 which were based on the EMCDDA model questionnaire.
Some modifications were required as appropriate to the Northern Ireland context, but
it was essential that it remained comparable with the questionnaire used in the
survey in Ireland.
2.2
Questionnaire Testing
As the 2010/11 questionnaire was based on the EMCDDA model and only relatively
minor revisions had been made to the questionnaire used in 2006/07, it was decided
that it was not necessary to conduct a pilot study in Northern Ireland.
However, extensive in-house testing of the questionnaire was carried out by CSU.
This ensured that any inconsistencies, routing problems, issues with question
wording, instructions etc were identified and corrected in advance of the fieldwork.
(The Final Questionnaire, Show cards & Interviewer Instructions used in the
Northern Ireland survey are provided in Appendices A, B & C)
7

3. Survey Design
3.1
Target Population
As in 2002/03 and 2006/07, the population for the 2010/11 survey was defined as all
adults, aged 15 to 64 years (inclusive), living in private households in Northern
Ireland and Ireland. Household surveys do not include people living in institutions
such as prisons (unless they live in private households in such institutions) or those
who are homeless. This report relates to the Northern Ireland survey only.
3.2
Selection of Sample
Sampling Frame
The POINTER list of domestic addresses was used as the sampling frame as it is the
most comprehensive and up-to-date listing of private households in Northern Ireland
and is available to the Northern Ireland Statistics and Research Agency (NISRA) for
research purposes.
Sample Size & Design
(a)
Households
The sample size was determined by the need to be able to provide robust data which
could be analysed by age, gender and Health and Social Care Trust (HSCT) area.
Budget and timing restrictions were also factors in deciding the sample size and
design. The POINTER list of addresses was therefore stratified by HSCT area and a
disproportionate random sample of private households was selected in each stratum
– the „over-sampling‟ in relation to population proportions in some strata would allow
prevalence estimates to be produced for people living in the smaller HSCT areas,
where sample size might be too small for meaningful analysis under a proportionate
stratification. CSU recommended an achieved sample of 2,500 individuals, evenly
distributed across the five HSCT areas in Northern Ireland. In order to achieve 500
interviews, 1100 addresses were randomly selected from each HSCT: this allowed
for 88% of addresses to be eligible (e.g. occupied, residential etc), 80% of eligible
households to contain an eligible adult (aged 15-64) and a 65% completion rate.
Advance letters were then sent to all selected households asking for participation in
the survey (See Appendix D for Advance Letter to Households).
Sampled
addresses
1,100
1,100
1,100
1,100
1,100
5,500
Health & Social Care Trust
(HSCT)
Belfast
Northern
South Eastern
Southern
Western
Northern Ireland
8
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(b)
Individuals
The POINTER list of addresses contains no information about the number of people
living at an address. Further selection stages were therefore required to convert the
listing of addresses to a listing of individuals.
CSU Interviewers were instructed to call at each address issued in their assignments.
Once contact was made at an address, the first stage was to identify the number of
households resident at the address and, where necessary, select one using the
following selection table.
Household Selection Table
Number of
1
2
3
households
Household
1
1
2
selected
4
5
6
7
8
9
10
11
12
3
4
4
2
7
6
8
6
6
The next stage involved the collection of demographic details about each member at
the selected household. A computerised random selection procedure based on the
Kish grid technique was then run to choose one respondent eligible to take part in the
survey (i.e. aged 15 to 64 years and living at the address). Only the selected
respondent was allowed to complete the interview and could not be replaced with
any other members of the household.
3.3
Administration of Questionnaire
The interview
Interviewers were required to try to persuade selected respondents to take part in the
survey. Once co-operation was achieved, information was collected using Computer
Assisted Personal Interviewing (CAPI), which is CSU‟s standard method of data
collection for household surveys. CAPI is also the preferred method under EMCDDA
guidelines. In this mode of interviewing, questionnaires were administered by CSU
interviewers in a face-to-face setting in the privacy of the respondents‟ own home.
Respondents were asked questions on their use of all drug types including tobacco,
alcohol, illegal drugs, some prescribed drugs and „legal highs‟. In addition,
respondents were asked about their attitudes and opinions to drug use and where
they had confirmed use of drugs, they were asked if they had ever tried to stop and
what influenced this decision. The length of the interview was approximately 25
minutes. However, this obviously varied depending on the extent of the respondent‟s
awareness and use of drugs.
At the outset, the survey did not make specific provision for interviews to be
conducted in languages other than English, although translation and interpreter
services were available as necessary. During the course of the fieldwork period, CSU
interviewers encountered several households where these services were required.
The advance letter to households and an appointment card were translated into the
following languages: Polish, Czech, Russian, Portuguese and Slovakian. However,
only a small number of interviews were conducted in Polish, Portuguese and
Slovakian with the aid of an interpreter? (Copies of the English version of the
advance letter to households and appointment card are provided in Appendix E).
9

Age
As in the 2002/03 and 2006/07 surveys, two sections of the population were
deliberately excluded from participating in the survey because of their age. The first
of these were those under 15 years of age, who were excluded in accordance with
EMCDDA guidelines: 15-year-olds are included in the survey as first use of illicit
drugs has often started by this age. When interviewing anyone under the age of 16,
it is a requirement to obtain full written consent of a parent or guardian: therefore, as
this survey included those aged 15, such consent was sought and obtained (See
Appendix G for Parental Permission Form). It should be noted that the parent or
guardian also had the right to sit in on the interview, if they so wished. As this had the
potential to influence the responses given by the respondent, interviewers were
instructed to explain the importance of conducting the interview in private. The table
below shows the proportion of 15-year-old respondents, who completed the interview
in the presence of a parent or guardian.
15-year-old respondents
Parent / guardian present
Parent / guardian not present
Total
68%
32%
100%
The second age group which was excluded were people aged 65 and over. The
EMCDDA suggests that responses from respondents in this age group may be less
reliable due to potential difficulties in being able to recall activities. There is also an
expectation that lifetime drug prevalence rates are not likely to be very high1 among
this age group.
1
EMCDDA Handbook for Surveys on Drug Use among the General Population (2002) page 79
10

4. Fieldwork
4.1
Fieldwork Period
The survey fieldwork was conducted in two phases: from 25th October 2010 to 17th
December 2010 and from 10th January 2011 to 30th April 2011, across all HSCT
areas. This was to allow a spread of interviews before and after Christmas 2010.
There were no differences in the questionnaires used or in sampling and interviewing
techniques used during either period.
4.2
Response Rate
A target response rate of 65% was set for the Northern Ireland Survey which would
result in a total of approximately 2,500 achieved interviews evenly distributed across
the five Health and Social Care Trusts.
The final response rate was 67%, with a total of 2,535 completed interviews. Details
of the overall response rate for Northern Ireland, along with rates for Health and
Social Care Trusts, are shown below.
Health & Social Care Trusts
Belfast
Northern
SouthEastern
Southern
Western
Total
1,100
1,100
1,100
1,100
1,100
5,500
Ineligible
addresses/persons
337
336
351
348
323
1,695
Eligible sample*
763
764
749
752
777
3,805
Non-contact
60
43
49
41
53
246
Refusal
213
178
185
155
164
895
28
26
20
18
37
129
462
517
495
538
523
2,535
61%
68%
66%
72%
67%
67%
Gross sample
Other nonresponse
Completed
Interviews
Response rate
*Eligible sample = Gross sample – (Ineligible addresses/persons)
4.3
Non-response and ineligibles
CSU interviewers encountered three different circumstances where they were unable
to complete an interview at a selected address: non-contacts, refusals and
ineligibles. Non-contacts are where the interviewer cannot make contact with anyone
at the selected address after 4 calls (in person) are made at different times of the day
and on different days of the week. Refusals are where the interviewer makes contact
at the address but all information about the members of household the household is
refused or where the selected respondent declines to take part in the interview. In
11

any survey, non-contacts and refusals constitute non-response. In the Drug
Prevalence Survey, ineligibles refer to both addresses and persons: i.e. where the
property was vacant, derelict, demolished, non-residential (e.g. business premises)
or where no-one in the selected household was in the specified age range to
participate in the survey. The table overleaf shows the distribution of non-response
and ineligible addresses/persons across the five HSCT areas.
Health & Social Care Trusts
Belfast
Northern
SouthEastern
Southern
Western
Total
Gross sample
100%
100%
100%
100%
100%
100%
Ineligible
addresses/persons
31%
31%
32%
32%
29%
31%
Eligible sample*
69%
69%
68%
68%
71%
69%
27%
22%
23%
19%
23%
23%
42%
47%
45%
49%
48%
46%
Non-contact /
Refusal / nonresponse
Completed
Interviews
Non-response accounted for nearly one quarter (23%) of all addresses in the gross
sample. There was some variation in the extent of non-response across the HSCTs,
with the highest proportion (27%) found in Belfast HSCT and the lowest proportion in
the Southern Trust.
Ineligible addresses accounted for three in ten addresses from the gross sample.
There was little variation in the proportion of ineligible addresses across the HSCTs.
4.4
Representativeness of the achieved sample
In any survey there is a possibility of non-response bias. Non-response bias arises if
the characteristics of non-respondents differ from those of respondents in such a way
that they are reflected in the responses given in the survey. Accurate estimates of
non-response bias can be obtained by comparing characteristics of the achieved
sample with the distribution of the same characteristics in the population at the time
of sampling.
The following table compares the characteristics of the achieved sample for the
survey with the characteristics of the Northern Ireland population (based on the 2009
mid-year population estimates) for those aged 15 – 64 years with regard to gender,
age and HSCT.
12

Population
% Population
Achieved
Sample
% Achieved
sample
1,177,207
100%
2,535
100%
Male
585,965
50%
1,163
46%
Female
591,242
50%
1,372
54%
15-24
257,631
22%
346
14%
25-34
239,439
20%
509
20%
35-44
254,721
22%
608
24%
45-54
236,085
20%
546
22%
55-64
189,331
16%
524
21%
-
-
2
< 0.5%
222,571
19%
462
18%
298,885
25%
495
20%
225,526
19%
517
20%
232,588
20%
538
21%
197,637
17%
523
21%
Northern Ireland
Gender
Age
55-64
2
Unknown
Belfast
Northern
Health &
South
Social
Eastern
Care Trust
Southern
Western
2
Two respondents refused to disclose their age.
13

5. Weighting
5.1
Weighting
A survey collects information from only part (a sample) of the total population being
studied, in this case 15-64 year olds who live in Northern Ireland. The results are
then used to draw conclusions about the whole population but it is important to note
that the results achieved are only estimators of population values.
It is common practice, when a survey sample is not fully representative (because
there are too many respondents from one group and not enough from another), to
weight the results. The main purpose of this weighting is to reduce bias in population
estimates by up-weighting population sub-groups that are under-represented and
down-weighting those that are over-represented in the sample. This process ensures
that the results more accurately represent the target population. A less desirable byproduct of weighting however is that it can, when the variance of the weights is large,
result in standard errors that are larger than they would be for unweighted estimates.
In this survey, the sample proportions were weighted back to those found in the
general population with regard to age, gender and HSCT area (based on the 2009
mid-year population estimates) for those aged 15 – 64 years. The net effect of
stratification and weighting is that the standard errors of the complex sample design
used in Northern Ireland are larger than those of a simple random sample. The
difference in the precision of estimates produced by a complex design relative to a
simple random sample is known as the design effect and this is also incorporated in
calculations for survey.
(See Appendix H for Technical Details on Design Effects and Confidence Intervals)
5.2
Calculation of NI and HSCT Weights
The achieved sample for the survey was subdivided into cells according to the
respondent‟s age group, gender and HSCT area (e.g. 15-24 year old males in the
Belfast HSCT area). Weights for each cell were then calculated by firstly establishing
the proportion of the overall achieved sample in each cell (the response ratio) and
the proportion of the overall population represented by the cell (the population ratio).
The weights for each cell could then be calculated by dividing the population ratio by
the response ratio. The weights used for reporting the findings of the survey for
Northern Ireland and each HSCT area are found in the tables overleaf.
14

HSCT
Belfast
Gender
Age
Population
%
Population
s
Achieved
sample
Male
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
27,956
23,601
21,033
20,247
15,617
27,818
23,593
22,728
23,192
16,786
32,051
28,835
33,276
30,221
24,769
30,457
29,046
33,928
30,897
25,405
23,356
21,582
24,132
23,098
19,747
21,780
21,859
25,302
24,062
20,608
26,715
24,913
25,325
22,852
17,484
24,875
24,819
25,245
22,512
17,848
21,739
20,644
21,677
19,533
15,562
20,884
20,547
22,075
19,471
15,505
2.374773511
2.004830077
1.786686624
1.719918417
1.326614606
2.363050848
2.004150502
1.930671496
1.970086824
1.425917447
2.722630769
2.449441772
2.826690633
2.567178075
2.104047971
2.587225526
2.467365553
2.882075965
2.62460213
2.158074153
1.984018104
1.833322432
2.049936842
1.962101822
1.677445003
1.850141904
1.856852703
2.14932463
2.043990564
1.750584222
2.269354498
2.116280314
2.151278407
1.941204903
1.485210333
2.113052335
2.108295313
2.144482661
1.912322981
1.516130978
1.846659084
1.753642308
1.84139238
1.659266382
1.32194253
1.774029546
1.745402465
1.875201218
1.653999679
1.317100561
30
51
40
47
25
38
68
62
61
39
29
43
61
62
50
33
56
69
35
56
28
45
59
50
60
36
36
70
64
69
38
52
52
57
46
43
62
69
58
61
34
45
54
53
50
37
51
72
59
68
All
1,177,207
100%
2,533
Female
Male
Northern
Female
Male
South
Eastern
Female
Male
Southern
Female
Male
Western
N Ireland
Female
All
3
%
Achieved
sample
1.184366364
2.013422819
1.579155152
1.855507304
0.98697197
1.500197394
2.684563758
2.447690486
2.408211607
1.539676273
1.144887485
1.697591788
2.408211607
2.447690486
1.97394394
1.302803
2.210817213
2.724042637
1.381760758
2.210817213
1.105408606
1.776549546
2.329253849
1.97394394
2.368732728
1.421239637
1.421239637
2.763521516
2.526648243
2.724042637
1.500197394
2.052901698
2.052901698
2.250296092
1.816028425
1.697591788
2.447690486
2.724042637
2.28977497
2.408211607
1.342281879
1.776549546
2.131859455
2.092380576
1.97394394
1.460718516
2.013422819
2.842479274
2.329253849
2.684563758
2.00510043
0.99573227
1.1314193
0.92692624
1.34412592
1.57515995
0.74654606
0.78877273
0.81807048
0.9261151
2.37807715
1.44289209
1.1737717
1.04881646
1.0659107
1.98589159
1.11604231
1.05801426
1.89946206
0.97614318
1.79482781
1.03195683
0.88008305
0.99400078
0.70816137
1.3017804
1.30650219
0.77774847
0.80897314
0.642642
1.51270393
1.0308727
1.04792081
0.86264421
0.8178343
1.24473525
0.86134065
0.78724269
0.83515761
0.62956717
1.37576102
0.98710577
0.86374943
0.7930041
0.66969609
1.21449104
0.86688322
0.65970621
0.71009851
0.49061996
100%
-
Two respondents refused to disclose their ages and thus cannot be included in the weight calculations.
They have each been given a weight of 1.
15
3
Weight

HSCT
Belfast
Gender
Age
Population
% Population
Male
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
All
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
All
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
All
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
All
15-24
25-34
35-44
45-54
55-64
15-24
25-34
35-44
45-54
55-64
All
27,956
23,601
21,033
20,247
15,617
27,818
23,593
22,728
23,192
16,786
222,571
32,051
28,835
33,276
30,221
24,769
30,457
29,046
33,928
30,897
25,405
298,885
23,356
21,582
24,132
23,098
19,747
21,780
21,859
25,302
24,062
20,608
225,526
26715
24913
25325
22852
17484
24875
24819
25245
22512
17848
232588
21739
20644
21677
19533
15562
20884
20547
22075
19471
15505
197637
12.56048632
10.60380732
9.450018196
9.096872459
7.016637388
12.49848363
10.60021297
10.21157294
10.42004574
7.541863046
100
10.72352243
9.647523295
11.13337906
10.1112468
8.287133847
10.19020694
9.718119009
11.35152316
10.33742075
8.49992472
100
10.35623387
9.569628336
10.70031837
10.24183464
8.755974921
9.657423091
9.692452311
11.21910556
10.66927982
9.137749084
100
11.4859752
10.71121468
10.88835194
9.825098457
7.517154797
10.69487678
10.67079987
10.85395635
9.678917227
7.673654703
100
10.9994586
10.44541255
10.96808796
9.883270845
7.874031684
10.5668473
10.39633267
11.16946726
9.851900201
7.845190931
100
Female
All
Male
Northern
Female
All
Male
South
Eastern
Female
All
Male
Southern
Female
All
Male
Western
Female
All
16
Achieved
sample
%
Achieved
sample
30
51
40
47
25
38
68
62
61
39
6.507592191
11.06290672
8.676789588
10.19522777
5.422993492
8.242950108
14.7505423
13.44902386
13.23210412
8.459869848
461
100
29
43
61
62
50
33
56
69
35
56
494
28
45
59
50
60
36
36
70
64
69
517
38
52
52
57
46
43
62
69
58
61
5.870445344
8.704453441
12.34817814
12.55060729
10.12145749
6.680161943
11.33603239
13.96761134
7.085020243
11.33603239
100
5.415860735
8.704061896
11.41199226
9.671179884
11.60541586
6.963249516
6.963249516
13.53965184
12.37911025
13.34622824
100
7.063197026
9.665427509
9.665427509
10.59479554
8.550185874
7.992565056
11.52416357
12.82527881
10.78066914
11.33828996
34
45
54
53
50
37
51
72
59
68
523
6.500956023
8.604206501
10.3250478
10.13384321
9.560229446
7.07456979
9.751434034
13.7667304
11.28107075
13.00191205
100
Weight
1.930128064
0.958501015
1.089114597
0.892267703
1.293867934
1.516263409
0.718632085
0.759279859
0.787482145
0.891486888
10.8370237
1.826696579
1.108343374
0.901621189
0.805638052
0.818768824
1.525443099
0.857276927
0.812703252
1.4590531
0.749814788
10.86535918
1.912204611
1.099443967
0.937638067
1.059005702
0.754473172
1.386913261
1.391943846
0.828611082
0.86187776
0.684669026
10.91678049
1.626172278
1.10819875
1.126525643
0.927351398
0.879180278
1.338103188
0.925950053
0.846293988
0.897803012
0.676791185
10.35236977
1.691975544
1.213989059
1.06227963
0.975273708
0.823623714
1.493638145
1.066133723
0.811337691
0.873312509
0.603387479
10.6149512

6. Statistical methods
6.1
Design Effects and Confidence Intervals
Background information and a detailed description of the methodology used to
incorporate survey design effects into the calculation of confidence intervals around
the prevalence rates can be found in Appendix H (Author: J Sevtsenko).
6.2
Statistical Reliability and Sampling Tolerances
Assuming no design effect, the following table shows statistical reliability at the 95%
confidence level, for each of the achieved sample sizes within the five HSCT areas in
Northern Ireland
Range of Error (+/-) for a range of Confidence Levels by sample sizes
(Assuming a simple random sample)
HSCT
Belfast
Northern
South Eastern
Southern
Western
Northern Ireland
Sample
size
5% or
95%
10% or
90%
20% or
80%
30% or
70%
50%
462
517
495
538
523
2,535
2.0
1.9
1.9
1.8
1.9
0.8
2.7
2.6
2.6
2.5
2.6
1.2
3.6
3.4
3.5
3.4
3.4
1.6
4.2
4.0
4.0
3.9
3.9
1.8
4.6
4.3
4.4
4.2
4.3
1.9
For example, with a total sample size of 2,535 and 10% of respondents gave a
particular answer, we can be 95% certain that the population value would fall within
the range of +/- 0.8 percentage points of the sample result.
6.3
Statistical Significance: Comparisons between 2002/03,
2006/07 and 2010/11
Statistical tests have been carried out to test for significant differences between the
2002/03, 2006/07 and 2010/11 drug prevalence rates. These tests are used to
establish the degree of confidence with which it can be inferred that the observed
changes in drug prevalence rates between the surveys are not due to sampling error.
Only results that are statistically significant at least at the 5% level are reported which
means that the likelihood that sampling error accounts for the observed changes is
less than 5%.
17

Appendices
A.
Questionnaire
B.
Showcards
C.
D.
Advance Letter to Households
E.
Advance Letter to Households (Polish version)
F.
Appointment Card (Polish version)
G.
Parental Permission Form
H.
Design Effects and Confidence Intervals: Julia Sevtsenko
18

A. Questionnaire
Drug Prevalence
Survey
2010/11
Northern Ireland
Questionnaire
19

TOBACCO QUESTIONS
Ask all
Introtob
First of all I'm going to ask a few questions about tobacco
: (Continue
"Press <1> to continue")
Ask all
Q1
"Do you smoke tobacco products, such as cigarettes, cigars or a pipe?"
: (Y
"Yes", N
"No")
Ask if Q1 = no (Does not smoke)
Q2
"Have you ever smoked tobacco products in the past?"
: (Y
"Yes", N
"No")
Ask if Q1 = yes (Smokes) OR (Q1 = no (does not smoke) AND Q2 = yes (Smoked in the
past))
Q3
"At what age did you smoke tobacco products for the first time?"
: 0..64
Ask if Q1 = yes (Smokes) OR Q2 = yes (Smoked in the past)
Q4
"During the last 12 months have you smoked tobacco products?"
: (Y
"Yes", N
"No")
Ask if (Q1 = yes (Smokes) OR Q2 = yes (Smoked in the past)) AND Q4 = yes (has smoked in
past 12 months)
Q5
"During the last 30 days have you smoked tobacco products?"
: (Y
"Yes", N
"No")
past 12 months) AND Q5 = yes (has smoked in past 30 days)
Q6
"During the last 30 days on how many days have you smoked?"
: 1..30
past 12 months) AND Q5 = yes (has smoked in past 30 days)
Q7
"What type of tobacco product do you most commonly use?
READ OUT - CODE ONE ONLY"
: (brand
"Branded cigarettes",
rollies
"Hand rolled cigarettes",
cigars
"Cigars",
pipe
"Pipe")
20

past 12 months) AND Q5 = yes (has smoked in past 30 days) AND Q7 = brand OR rollies
(Smokes cigarettes)
Q8
"During the last 30 days how many cigarettes have you smoked on an average
day?
READ OUT"
: (perwk
"Less than 1 cigarette per week",
perday
"Less than 1 cigarette per day",
five
"1-5 cigarettes per day",
ten
twenty
more
"More than 20 cigarettes per day")
ALCOHOL QUESTIONS
Ask all
Introalc
"Now I'm going to ask a few questions about alcohol"
: (Continue
Ask all
Q9
"Do you drink alcohol?"
: (Y
"Yes", N
"No")
Ask if Q9 = no (Does not drink)
Q10
"Have you ever drunk alcohol?"
: (Y
"Yes", N
"No")
Ask if Q9 = yes (Drinks) OR Q10 = yes (Has drunk alcohol before)
Q11
"At what age did you first drink alcohol?"
: 0..64
Ask if Q9 = yes (Drinks) OR Q10 = yes (Has drunk alcohol before)
Q12
"During the last 12 months, have you drunk any alcohol?"
: (Y
"Yes", N
"No")
Ask if (Q9 = yes (Drinks) OR Q10 = yes (Has drunk alcohol before)) AND Q12 = yes (Has
drunk alcohol in the past 12 months)
Q13
"During the last 30 days, have you drunk any alcohol?"
: (Y
"Yes", N
"No")
Ask if (Q9 = yes (Drinks) OR Q10 = yes (Has drunk alcohol before)) AND (Q12 = yes (Has
drunk alcohol in the past 12 months) AND Q13= yes (Has drunk alcohol in the past 30 days))
Q14
"During the last 30 days, on how many days have you drunk alcohol?"
:1..30
21

MEDICINE QUESTIONS
SEDATIVES OR TRANQUILISERS
Ask all
Intromed
"Now I'm going to ask a few questions about drugs that are sometimes used as
medicines"
: (Continue
Ask all
Q16
"SHOWCARD 16
Have you ever heard of any of these?"
: (Y
"Yes", N
"No")
Ask if Q16 = yes (Has heard of sedatives or tranquilisers)
Q17
"SHOWCARD 16
All of the drugs listed on this card are names for sedatives or tranquilisers. Do you
personally know people who take sedatives or tranquillisers?"
: (Y
"Yes", N
"No")
Ask if Q16 = yes (Has heard of sedatives or tranquilisers)
Q18
"Have you ever taken sedatives or tranquillisers?"
: (Y
"Yes", N
"No")
Ask if Q16 = yes (Has heard of sedatives or tranquilisers) AND Q18 = yes (Has taken
sedatives or tranquillisers)
Q19
"At what age did you first take sedatives or tranquillisers?"
: 0..64
sedatives or tranquillisers)
Q20
"During the last 12 months have you taken sedatives or tranquillisers?"
: (Y
"Yes", N
"No")
sedatives or tranquillisers) AND Q20 = yes (Has taken sedatives or tranquillisers in the past
12 months)
Q21
"During the last 30 days have you taken sedatives or tranquillisers?"
: (Y
"Yes",
N
"No")
22

12 months) AND Q21 = yes (Has taken sedatives or tranquillisers in the past 30 days)
Q22
"During the last 30 days, on how many days have you taken sedatives or
tranquillisers?"
:1..30
Ask if Q16 = yes (Has heard of sedatives or tranquillisers) AND Q18 = yes (Has taken
Q23
"SHOWCARD 23
What method do you most commonly use to take sedatives or tranquillisers?
Just call me out the number from the card
CODE ONE ONLY"
: (oral
"Oral (Tablets or syrup)",
needle
"Injection with a needle",
other
"Other (Please specify)")
12 months) AND Q21 = yes (Has taken sedatives or tranquillisers in the past 30 days) AND
Q23 = Other (Uses another method to take sedatives or tranquillisers)
Spec23
"What is the other method that you most commonly use to take sedatives or
tranquillisers?"
: STRING [255]
Q24
"SHOWCARD 24
On the last occasion you took sedatives or tranquillisers how had you obtained
them?
Just call me out the number from the card.
CODE ONE ONLY"
(pre
"I got them on a prescription",
know "I got them from someone I know",
chem "I bought them without a prescription in a chemist",
innet "I bought them over the internet",
other "Other (Please specify)")
12 months) AND Q21 = yes (Has taken sedatives or tranquillisers in the past 30 days) AND
Q24 = Other (Obtained sedatives or tranquillisers another way)
Spec24
"What was the other way you had obtained the sedatives or tranquillisers?"
: STRING [255]
23

ANTI-DEPRESSANTS
Ask all
Q25
"SHOWCARD 25
: (Y
"Yes", N
"No")
Ask IF Q25 = yes (Has heard of anti-depressants)
Q26
"SHOWCARD 25
All of the drugs listed on this card are names for anti-depressants. Do you
personally know people who take anti-depressants?"
: (Y
"Yes", N
"No")
Ask IF Q25 = yes (Has heard of anti-depressants)
Q27
"Have you ever taken anti-depressants?"
: (Y
"Yes", N
"No")
Ask IF Q25 = yes (Has heard of anti-depressants) AND Q27 = yes (Has taken antidepressants)
Q28
"At what age did you first take anti-depressants?"
: 0..64
Ask IF Q25 = yes (Has heard of anti-depressants) AND Q27 = yes (Has taken antidepressants)
Q29
"During the last 12 months have you taken anti-depressants?"
: (Y
"Yes", N
"No")
Ask IF (Q25 = yes (Has heard of anti-depressants) AND Q27 = yes (Has taken antidepressants)) AND Q29 = yes (Has taken anti-depressants in the past 12 months)
Q30
"During the last 30 days have you taken anti-depressants?"
: (Y
"Yes", N
"No")
Ask IF (Q25 = yes (Has heard of anti-depressants) AND Q27 = yes (Has taken antidepressants)) AND Q29 = yes (Has taken anti-depressants in the past 12 months) AND Q30
= yes (Has taken anti-depressants in the past 30 days)
Q31
"During the last 30 days, on how many days have you taken anti-depressants?"
: 0..30
Q32
"SHOWCARD 32
What method do you most commonly use to take anti-depressants?
CODE ONE ONLY"
: (tab
"Oral (tablets or syrup)",
needle
"Injection with a needle",
other
"Other (Please specify)")
24

= yes (Has taken anti-depressants in the past 30 days) AND Q32 = Other (Uses another
method to take anti-depressants)
Spec32
"What is the other method that you most commonly use to take antidepressants?"
: STRING [255]
Q33
“SHOWCARD 33
On the last occasion you took anti-depressants how had you obtained them?
CODE ONE ONLY"
: (pre "I got them on a prescription",
know "I got them from someone I know",
innet "I bought them over the internet",
other "Other (Please specify)")
= yes (Has taken anti-depressants in the past 30 days) AND Q33 = Other (Obtained antidepressants by another method)
Spec33
"What was the other way you had obtained the anti-depressants?"
: STRING [255]
25

ILLEGAL DRUGS QUESTIONS
CANNABIS QUESTIONS
Ask all
Introdru
"Now I'm going to ask a few questions about other drugs"
: (Continue
Ask all
Q34
"SHOWCARD 34
: (Y
"Yes", N
"No")
Ask if Q34 = yes (has heard of cannabis)
Q35
"SHOWCARD 34
All of the drugs listed on this card are names for cannabis. Do you personally
know people who take cannabis?"
: (Y
"Yes", N
"No")
Q36
"Have you ever taken cannabis?"
: (Y
"Yes", N
"No")
Ask if Q34 = yes (has heard of cannabis) AND Q36 = yes (has taken cannabis)
Q37
"At what age did you first take cannabis?"
: 0..64
Q38
“SHOWCARD 38
How many times have you been offered cannabis either free of charge or to buy in
the last 12 months?
CODE ONE ONLY"
: (non
"None",
once
"Once or twice",
three
"3 to 5 times",
six
"6 to 9 times",
ten
"10 to 19 times",
twenty
"20 times or more")
Ask if Q34 = yes (has heard of cannabis) AND Q36 = yes (has taken cannabis)
Q39
"During the last 12 months have you taken cannabis?"
: (Y
"Yes", N
"No")
Ask if Q34 = yes (has heard of cannabis) AND Q36 = yes (has taken cannabis) AND Q39 =
yes (has taken cannabis in the last 12 months)
Q40
"During the last 30 days have you taken cannabis?"
: (Y
"Yes", N
"No")
26

yes (has taken cannabis in the last 12 months) AND Q40 = yes (has taken cannabis in the
last 30 days)
Q41
"During the last 30 days, on how many days have you taken cannabis?"
:1..30
last 30 days)
Q42
"SHOWCARD 42
What type of cannabis do you most commonly use?
CODE ONE ONLY"
: (Grass, Weed, Skunk, Hash Oil, Herb, Hash, Resin, Other (Please specify))
last 30 days) AND (Q42 = grass OR weed OR herb) (most commonly uses another type of
cannabis)
Spec42
"What is the other type of cannabis that you most commonly use?"
: STRING [255]
last 30 days) AND (Q42 = grass OR weed OR herb OR skunk (most commonly uses grass,
weed, herb or skunk))
Q43
"Is it grown in Northern Ireland?
CODE ONE ONLY"
: Yndk
last 30 days)
Q44
"SHOWCARD 44
What method do you most commonly use to take cannabis?
CODE ONE ONLY"
: (Joint, Pipe, Bong, Eat, Other (Please specify))
last 30 days) AND Q44 = Other (Uses another method to take cannabis)
Spec44
"What is the other method that you most commonly use to take cannabis?"
: STRING [255]
27

ECSTASY QUESTIONS
Ask all
Q45
"SHOWCARD 45
: (Y
"Yes", N
"No")
Ask if Q45 = yes (Has heard of ecstasy)
Q46
"SHOWCARD 45
All of the drugs listed on this card are names for ecstasy. Do you personally know
people who take ecstasy?"
: (Y
"Yes", N
"No")
Q47
"Have you ever taken ecstasy?"
: (Y
"Yes", N
"No")
Ask if Q45 = yes (Has heard of ecstasy) AND Q47 = yes (Has taken ecstasy)
Q48
"At what age did you first take ecstasy?"
: 0..64
Q49
"SHOWCARD 49
How many times have you been offered ecstasy either free of charge or to buy in
the last 12 months?
CODE ONE ONLY"
: (non "None",
once "Once or twice",
three "3 to 5 times",
six "6 to 9 times",
ten "10 to 19 times",
twenty "20 times or more")
Ask if Q45 = yes (Has heard of ecstasy) AND Q47 = yes (Has taken ecstasy)
Q50
"During the last 12 months have you taken ecstasy?"
: (Y
"Yes", N
"No")
Ask if Q45 = yes (Has heard of ecstasy) AND Q47 = yes (Has taken ecstasy) AND Q50 = yes
(Has taken ecstasy in the past 12 months)
Q51
"During the last 30 days have you taken ecstasy?"
: (Y
"Yes", N
"No")
Ask if Q45 = yes (Has heard of ecstasy) AND Q47 = yes (Has taken ecstasy) AND Q50 = yes
(Has taken ecstasy in the past 12 months) AND Q51 = yes (Has taken ecstasy in the past 30
days)
Q52
"During the last 30 days, on how many days have you taken ecstasy?"
:1..30
28

AMPHETAMINES QUESTIONS
Ask all
Q53
"SHOWCARD 53
: (Y
"Yes", N
"No")
Ask if Q53 = yes (Has heard of amphetamines)
Q54
"SHOWCARD 53
All of the drugs listed on this card are names for amphetamines. Do you
personally know people who take amphetamines?"
: (Y
"Yes", N
"No")
Q55
"Have you ever taken amphetamines?"
: (Y
"Yes", N
"No")
Ask if Q53 = yes (Has heard of amphetamines) AND Q55 = yes (Has taken amphetamines)
Q56
"At what age did you first take amphetamines?"
: 0..64
Q57
"SHOWCARD 57
How many times have you been offered amphetamines either free of charge or to
buy in the last 12 months?
CODE ONE ONLY"
: (non
"None",
once
"Once or twice",
three
"3 to 5 times",
six
"6 to 9 times",
ten
"10 to 19 times",
twenty
"20 times or more")
Ask if Q53 = yes (Has heard of amphetamines) And Q55 = yes (Has taken amphetamines)
Q58
"During the last 12 months have you taken amphetamines?"
: (Y
"Yes", N
"No")
AND Q58 = yes (Has taken amphetamines during the last 12 months)
Q59
"During the last 30 days have you taken amphetamines?"
: (Y
"Yes", N
"No")
AND Q58 = yes (Has taken amphetamines during the last 12 months) AND Q59 = yes (Has
taken amphetamines in the last 30 days)
Q60
"During the last 30 days, on how many days have you taken amphetamines?"
:1..30
29

CRACK QUESTIONS
Ask all
Q62
"SHOWCARD 62
: (Y
"Yes", N
"No")
Ask if Q62 = yes (Has heard of crack)
Q63
"SHOWCARD 62
All of the drugs listed on this card are names for crack. Do you personally know
people who take crack?"
: (Y
"Yes", N
"No")
Q64
"Have you ever taken crack?"
: (Y
"Yes", N
"No")
Ask if Q62 = yes (Has heard of crack) AND Q64 = yes (Has taken crack)
Q65
"At what age did you first take crack?"
: 0..64
Q66
"SHOWCARD 66
How many times have you been offered crack either free of charge or to buy in the
last 12 months?
CODE ONE ONLY"
:(non
"None",
once
"Once or twice",
three
"3 to 5 times",
six
"6 to 9 times",
ten
"10 to 19 times",
twenty
"20 times or more")
Ask if Q62 = yes (Has heard of crack) AND Q64 = yes (Has taken crack)
Q67
"During the last 12 months have you taken crack?"
: (Y
"Yes", N
"No")
Ask if Q62 = yes (Has heard of crack) AND Q64 = yes (Has taken crack) AND Q67 = yes (Has
taken crack in the past 12 months)
Q68
"During the last 30 days have you taken crack?"
: (Y
"Yes", N
"No")
Ask if Q62 = yes (Has heard of crack) AND Q64 = yes (Has taken crack) AND Q67 = yes (Has
taken crack in the past 12 months) AND Q68 = yes (Has taken crack in the past 30 days)
Q69
"During the last 30 days, on how many days have you taken crack?"
:1..30
30

COCAINE QUESTIONS
Ask all
Q70
"SHOWCARD70
: (Y
"Yes", N
"No")
Ask if Q70 = yes (Has heard of cocaine)
Q71
"SHOWCARD 70
All of the drugs listed on this card are names for cocaine. Do you personally know
people who take cocaine?"
: (Y
"Yes", N
"No")
Q72
"Have you ever taken cocaine?"
: (Y
"Yes", N
"No")
Ask if Q70 = yes (Has heard of cocaine) AND Q72 = yes (Has taken cocaine)
Q73
"At what age did you first take cocaine?"
: 0..64
Q74
"SHOWCARD 74
How many times have you been offered cocaine either free of charge or to buy in
the last 12 months?
CODE ONE ONLY"
:(non
"None",
once
"Once or twice",
three
"3 to 5 times",
six
"6 to 9 times",
ten
"10 to 19 times",
twenty
"20 times or more")
Ask if Q70 = yes (Has heard of cocaine) AND Q72 = yes (Has taken cocaine)
Q75
"During the last 12 months have you taken cocaine?"
: (Y "Yes", N "No")
Ask if Q70 = yes (Has heard of cocaine) AND Q72 = yes (Has taken cocaine) AND Q75 = yes
(Has taken cocaine during the last 12 months)
Q76
"During the last 30 days have you taken cocaine?"
: (Y "Yes", N "No")
(Has taken cocaine during the last 12 months) AND Q76 = yes (Has taken cocaine in the last
30 days)
Q77
"During the last 30 days, on how many days have you taken cocaine?"
:1..30
31

30 days)
Q78
"SHOWCARD 78
What method do you most commonly use to take cocaine?
CODE ONE ONLY"
: (snort "Doing a line / snort",
inject "Injection with a needle",
smoke "Smoke",
Other "Other (Please specify)")
30 days) AND Q78 = yes (Uses another method to take cocaine)
Spec78
"What is the other method that you most commonly use to take cocaine?"
: STRING [255]
32

HEROIN QUESTIONS
Ask all
Q79
"SHOWCARD 79
: (Y "Yes", N "No")
Ask If Q79 = yes (Has heard of heroin)
Q80
"SHOWCARD 79
All of the drugs listed on this card are names for heroin. Do you personally know
people who take heroin?"
: (Y "Yes", N "No")
Q81
"Have you ever taken heroin?"
: (Y "Yes", N "No")
Ask If Q79 = yes (Has heard of heroin) And Q81 = yes (Has taken heroin)
Q82
"At what age did you first take heroin?"
: 0..64
Q83
"SHOWCARD 83
How many times have you been offered heroin either free of charge or to buy in
the last 12 months?
CODE ONE ONLY"
: ( non "None",
Three "3 to 5 times",
Six "6 to 9 times",
Ask If Q79 = yes (Has heard of heroin) And Q81 = yes (Has taken heroin)
Q84
"During the last 12 months have you taken heroin?"
: (Y "Yes", N "No")
Ask If Q79 = yes (Has heard of heroin) And Q81 = yes (Has taken heroin) AND Q84 = yes
(Has taken heroin during the last 12 months)
Q85
"During the last 30 days have you taken heroin?"
: (Y "Yes", N "No")
(Has taken heroin during the last 12 months) AND Q85 = yes (Has taken heroin during the
last 30 days)
Q86
"During the last 30 days, on how many days have you taken heroin?"
: 1..30
33

last 30 days)
Q87
"SHOWCARD 87
What method do you most commonly use to take heroin?
CODE ONE ONLY"
:(Smoke "Smoke",
inject "Injection with a needle",
dragon "Chasing the dragon",
last 30 days) AND Q87 = Other (Uses another method to take heroin)
Spec87
"What is the other method that you most commonly use to take heroin?"
: STRING [255]
34

LSD QUESTIONS
Ask all
Q88
"SHOWCARD 88
: (Y "Yes", N "No")
Ask if Q88 = yes (Has heard of LSD)
Q89
"SHOWCARD 88
All of the drugs listed on this card are names for LSD. Do you personally know
people who take LSD?"
: (Y "Yes", N "No")
Q90
"Have you ever taken LSD?"
: (Y "Yes", N "No")
Ask if Q88 = yes (Has heard of LSD) AND Q90 = yes (Has taken LSD)
Q91
"At what age did you first take LSD?"
: 0..64
Q92
"SHOWCARD 92
How many times have you been offered LSD either free of charge or to buy in the
last 12 months?
CODE ONE ONLY"
:( non "None",
Six "6 to 9 times",
Ask if Q88 = yes (Has heard of LSD) AND Q90 = yes (Has taken LSD)
Q93
"During the last 12 months have you taken LSD?"
: (Y "Yes", N "No")
Ask if Q88 = yes (Has heard of LSD) AND Q90 = yes (Has taken LSD) AND Q93 = yes (Has
taken LSD in the past 12 months)
Q94
"During the last 30 days have you taken LSD?"
: (Y "Yes", N "No")
Ask if Q88 = yes (Has heard of LSD) AND Q90 = yes (Has taken LSD) AND Q93 = yes (Has
taken LSD in the past 12 months) AND Q94 = yes (Has taken LSD in the past 30 days)
Q95
"During the last 30 days, on how many days have you taken LSD?"
:1..30
35

SOLVENTS QUESTIONS
Ask all
Q96
"SHOWCARD 96
: (Y "Yes", N "No")
Ask if Q96 = yes (Has heard of solvents)
Q97
"SHOWCARD 96
All of the things listed on this card are solvents. Do you personally know people
who take solvents?"
: (Y "Yes", N "No")
Q98
"Have you ever taken solvents?"
: (Y "Yes", N "No")
Ask if Q96 = yes (Has heard of solvents) AND Q98 = yes (Has taken solvents)
Q99
"At what age did you first take solvents?"
: 0..64
Q100
"SHOWCARD 100
How many times have you been offered solvents either free of charge or to buy in
the last 12 months?
CODE ONE ONLY"
:( non "None",
Six "6 to 9 times",
Ask if Q96 = yes (Has heard of solvents) AND Q98 = yes (Has taken solvents)
Q101
"During the last 12 months have you taken solvents?"
: (Y "Yes", N "No")
Ask if Q96 = yes (Has heard of solvents) AND Q98 = yes (Has taken solvents) AND Q101 =
yes (Has taken solvents in the last 12 months)
Q102
"During the last 30 days have you taken solvents?"
: (Y "Yes", N "No")
Ask if Q96 = yes (Has heard of solvents) AND Q98 = yes (Has taken solvents) AND Q101 =
yes (Has taken solvents in the last 12 months) AND Q102 = yes (Has taken solvents in the
past 30 days)
Q103
"During the last 30 days, on how many days have you taken solvents?"
: 1..30
36

POPPERS QUESTIONS
Ask all
Q104
"SHOWCARD 104
: (Y "Yes", N "No")
Ask Q104 = yes (Has heard of poppers)
Q105
"SHOWCARD 104
All of the drugs listed on this card are names for poppers. Do you personally know
people who take poppers?"
: (Y "Yes", N "No")
Q106
"Have you ever taken poppers?"
: (Y "Yes", N "No")
Ask Q104 = yes (Has heard of poppers) AND Q106 = yes (Has taken poppers)
Q107
"At what age did you first take poppers?"
: 0..64
Q108
"SHOWCARD 108
How many times have you been offered poppers either free of charge or to buy in
the last 12 months?
CODE ONE ONLY"
: ( non "None",
Six "6 to 9 times",
Ask Q104 = yes (Has heard of poppers) AND Q106 = yes (Has taken poppers)
Q109
"During the last 12 months have you taken poppers?"
: (Y "Yes", N "No")
Ask Q104 = yes (Has heard of poppers) AND Q106 = yes (Has taken poppers) AND Q109 =
yes (Has taken poppers in the past 12 months)
Q110
"During the last 30 days have you taken poppers?"
: (Y "Yes", N "No")
Ask Q104 = yes (Has heard of poppers) AND Q106 = yes (Has taken poppers) AND Q109 =
yes (Has taken poppers in the past 12 months) AND Q110 = yes (Has taken poppers in the
past 30 days)
Q111
"During the last 30 days, on how many days have you taken poppers?"
: 1..30
37

MAGIC MUSHROOMS QUESTIONS
Ask all
Q112
"SHOWCARD 112
: (Y "Yes", N "No")
Ask if Q112 = yes (Has heard of magic mushrooms)
Q113
"SHOWCARD 112
All of the drugs listed on this card are names for magic mushrooms. Do you
personally know people who take magic mushrooms?"
: (Y "Yes", N "No")
Q114
"Have you ever taken magic mushrooms?"
: (Y "Yes", N "No")
Ask if Q112 = yes (Has heard of magic mushrooms) AND Q114 = yes (Has taken magic
mushrooms)
Q115
"At what age did you first take magic mushrooms?"
: 0..64
Q116
"SHOWCARD 116
How many times have you been offered magic mushrooms either free of charge or
to buy in the last 12 months?
CODE ONE ONLY"
:( non "None",
Six "6 to 9 times",
mushrooms)
Q117
"During the last 12 months have you taken magic mushrooms?"
: (Y "Yes", N "No")
mushrooms) AND Q117 = yes (Has taken magic mushrooms in the past 12 months)
Q118
"During the last 30 days have you taken magic mushrooms?"
: (Y "Yes", N "No")
mushrooms) AND Q117 = yes (Has taken magic mushrooms in the past 12 months) AND
Q118 = yes (Has taken magic mushrooms in the past 30 days)
Q119
"During the last 30 days, on how many days have you taken magic mushrooms?"
:1..30
38

Q118 = yes (Has taken magic mushrooms in the past 30 days)
Q120
"SHOWCARD 120
On the last occasion you took magic mushrooms how had you obtained them?
CODE ONE ONLY"
:
(Pick "I picked them myself",
someone "I got them from someone I know",
inter "I bought them off the Internet",
shop "I bought them in a shop/market",
Q118 = yes (Has taken magic mushrooms in the past 30 days) AND Q120 = other (Obtained
the magic mushrooms in another way)
spec120
"What is the other way you obtained them?"
: STRING [255]
39

METHADONE QUESTIONS
Ask all
Q121
"SHOWCARD 121
: (Y "Yes", N "No")
Ask if Q121 = yes (Has heard of methadone)
Q122
"SHOWCARD 121
All of the drugs listed on this card are names for methadone.
Do you personally know people who take methadone?"
: (Y "Yes", N "No")
Ask if Q121 = yes (Has heard of methadone)
Q123
"Have you ever taken methadone?"
: (Y "Yes", N "No")
Ask if Q121 = yes (Has heard of methadone) AND Q123 = yes (Has taken methadone)
Q124
"At what age did you first take methadone?"
: 0..64
Ask if Q121 = yes (Has heard of methadone) AND Q123 = yes (Has taken methadone)
Q125
"During the last 12 months have you taken methadone?"
: (Y "Yes", N "No")
Ask if Q121 = yes (Has heard of methadone) AND Q123 = yes (Has taken methadone) AND
Q125 = yes (Has taken methadone in the past 12 months)
Q126
"During the last 30 days have you taken methadone?"
: (Y "Yes", N "No")
Q125 = yes (Has taken methadone in the past 12 months) AND Q126 = yes (Has taken
methadone in the past 30 days)
Q127
"During the last 30 days, on how many days have you taken methadone?"
: 1..30
methadone in the past 30 days)
Q128
"SHOWCARD 128
On the last occasion you took methadone how had you obtained it?
CODE ONE ONLY"
: ( Prescrip "I got it on a prescription",
someone "I got it from someone I know",
chem "I bought it without a prescription in a chemist",
inter "I bought it over the Internet",
40

methadone in the past 30 days) AND Q128 = other (obtained methadone another way)
Spec128
"What is the other way you obtained methadone?"
:STRING [255]
41

OTHER OPIATES QUESTIONS
Ask all
Q138
"SHOWCARD 138
I would now like to ask you about other opiates excluding heroin and methadone
which I have previously asked you about. Have you ever heard of any of these?"
: (Y "Yes", N "No")
Ask if Q138 = yes (Has heard of other opiates)
Q139
"SHOWCARD 138
All of the drugs listed on this card are names for other opiates excluding heroin
and methadone. Do you personally know people who take other opiates?"
: (Y "Yes", N "No")
Ask if Q138 = yes (Has heard of other opiates)
Q140
"Have you ever taken other opiates?"
: (Y "Yes", N "No")
Ask if Q138 = yes (Has heard of other opiates) AND Q140 = yes (Has taken other opiates)
Q141
"At what age did you first take other opiates?"
: 0..64
Q142
"During the last 12 months have you taken other opiates?"
: (Y "Yes", N "No")
AND Q142 = yes (Has taken other opiates in the past 12 months)
Q143
"During the last 30 days have you taken other opiates?"
: (Y "Yes", N "No")
AND Q142 = yes (Has taken other opiates in the past 12 months) AND Q143 = yes (Has
taken other opiates in the past 30 days)
Q144
"During the last 30 days, on how many days have you taken other opiates?"
: 1..30
taken other opiates in the past 30 days)
Q145
"SHOWCARD 145
On the last occasion you took other opiates how had you obtained them?
CODE ONE ONLY"
: (Prescr "I got them on a prescription",
inter "I bought them over the Internet",
42

taken other opiates in the past 30 days) AND Q145 = other (obtained the other opiates in
another way)
Spec145
"What is the other way you obtained other opiates?"
: STRING [255]
43

ANABOLIC STEROIDS QUESTIONS
Ask all
Q146
"SHOWCARD 146
: (Y "Yes", N "No")
Ask if Q146 = yes (Has heard of anabolic steroids)
Q147
"SHOWCARD 146
All of the drugs listed on this card are names for anabolic steroids. Do you
personally know people who take anabolic steroids?"
: (Y "Yes", N "No")
Ask if Q146 = yes (Has heard of anabolic steroids)
Q148
"Have you ever taken anabolic steroids?"
: (Y "Yes", N "No")
Ask if Q146 = yes (Has heard of anabolic steroids) AND Q148 = yes (Has taken anabolic
steroids)
Q149
"At what age did you first take anabolic steroids?"
: 0..64
steroids)
Q150
"During the last 12 months have you taken anabolic steroids?"
: (Y "Yes", N "No")
steroids) AND Q150 = yes (Has taken anabolic steroids in the past 12 months)
Q151
"During the last 30 days have you taken anabolic steroids?"
: (Y "Yes", N "No")
steroids) AND Q150 = yes (Has taken anabolic steroids in the past 12 months) AND Q151 =
yes (Has taken anabolic steroids in the past 30 days)
Q152
"During the last 30 days, on how many days have you taken anabolic steroids?"
: 1..30
yes (Has taken anabolic steroids in the past 30 days)
Q153
"SHOWCARD 153
On the last occasion you took anabolic steroids how had you obtained them?
CODE ONE ONLY"
: (Prescr "I got them on a prescription",
inter "I bought them over the Internet",
44

yes (Has taken anabolic steroids in the past 30 days) AND Q153 = Other (Obtained anabolic
steroids in another way)
Spec153
"What is the other way you obtained anabolic steroids?"
: STRING [255]
45

MEPHEDRONE QUESTIONS
Ask all
Q153a
"SHOWCARD 153a
: (Y "Yes", N "No")
Ask if Q153a = yes (Has heard of mephedrone)
Q153b
"SHOWCARD 153a
All of the substances listed on this card are names for mephedrone (formerly known
as a legal high until 16 April 2010). Do you personally know people who take
mephedrone?"
: (Y "Yes", N "No")
Ask if Q153a = yes (Has heard of mephedrone)
Q153c
"Have you ever taken mephedrone?"
: (Y "Yes", N "No")
Ask if Q153a = yes (Has heard of mephedrone) AND Q153c= yes (Has taken mephedrone)
Q153d
"At what age did you first take mephedrone?"
: 0..64
Ask if Q153a = yes (Has heard of mephedrone) AND Q153c = yes (Has taken mephedrone)
Q153e
"During the last 12 months have you taken mephedrone?"
: (Y "Yes", N "No")
AND Q153e = yes (Has taken mephedrone in the past 12 months)
Q153f
"During the last 30 days have you taken mephedrone?"
: (Y "Yes", N "No")
AND Q153e = yes (Has taken mephedrone in the past 12 months) AND Q153f = yes (Has
taken mephedrone in the past 30 days)
Q153g
"During the last 30 days, on how many days have you taken mephedrone?"
: 1..30
AND Q153e = yes (Has taken mephedrone in the past 12 months) AND Q153f = yes (Has
taken mephedrone in the past 30 days)
Q153h
"SHOWCARD 153h
On the last occasion you took mephedrone how had you obtained it?
CODE ONE ONLY"
: (someone "I got it from someone I know",
inter "I bought it over the Internet",
shop "I bought it in a headshop",
market "I bought it in a market",
46

AND Q153e= yes (Has taken mephedrone in the past 12 months) AND Q153f = yes (Has
taken mephedrone in the past 30 days) AND Q153h = Other (Obtained mephedrone in
another way)
Spec153h
"What is the other way you obtained mephedrone?"
: STRING [255]
47

LEGAL HIGH QUESTIONS
Ask all
Q153i
"SHOWCARD 153i
: (Y "Yes", N "No")
Ask if Q153i = yes (Has heard of legal highs)
Q153j
"SHOWCARD 153i
All of the substances listed on this card are names for legal highs (excluding
mephedrone which I have previously asked you about). Do you personally know
people who take legal highs?"
: (Y "Yes", N "No")
Ask if Q153i = yes (Has heard of legal highs)
Q153k
"Have you ever taken legal highs (excluding mephedrone)?"
: (Y "Yes", N "No")
Ask if Q153i = yes (Has heard of legal highs) AND Q153k = yes (Has taken legal highs)
Q153l
"SHOWCARD 153i
Which of the legal highs listed on this card have you ever taken?
Just call me out the number(s) from the card.
CODE AS MANY AS APPLY"
: (HH “Party pills or Herbal Highs”,
PP “Party Powders”
KR “Kratom”,
SD “Salvia Divinorum”)
Ask if Q153i= yes (Has heard of legal highs) AND Q153k= yes (Has taken legal highs)
Q153m
"At what age did you first take legal highs?"
: 0..64
Ask if Q153i = yes (Has heard of legal highs) AND Q153k = yes (Has taken legal highs)
Q153n
"During the last 12 months have you taken legal highs?"
: (Y "Yes", N "No")
Ask if Q153i = yes (Has heard of legal highs) AND Q153k = yes (Has taken legal highs) AND
Q153n = yes (Has taken legal highs in the past 12 months)
Q153o
"During the last 30 days have you taken legal highs?"
: (Y "Yes", N "No")
Q153n = yes (Has taken legal highs in the past 12 months) AND Q153o = yes (Has taken
legal highs in the past 30 days)
Q153p
"During the last 30 days, on how many days have you taken legal highs?"
: 1..30
48

Q153q
"SHOWCARD 153i
On the last occasion you took legal highs, which one of the substances listed on
this card did you take? Just call me out the number from the card.
CODE ONE ONLY"
: (HH “Party pills or Herbal Highs”,
PP “Party Powders”
KR “Kratom”,
SD “Salvia Divinorum”)
Q153r
"SHOWCARD 153r
On the last occasion you took [name of legal high], how had you obtained
it/them? Just call me out the number from the card.
CODE ONE ONLY"
: (Someone "I got it/them from someone I know",
inter "I bought it/them over the Internet",
shop "I bought it/them in a headshop",
market "I bought it/them in a market",
Ask if Q153i = yes (Has heard of legal highs) AND Q153k= yes (Has taken legal highs) AND
Q153n= yes (Has taken legal highs in the past 12 months) AND Q153o = yes (Has taken
other legal highs in the past 30 days) AND Q153r = Other (Obtained legal highs in another
way)
Spec153r
"What is the other way you obtained [name of legal high]?"
: STRING [255]
49

OPINION QUESTIONS
Ask all
introopi
"I'd like to ask you for your opinions on different matters relating to drugs."
: (Continue
Ask all
Q154
"SHOWCARD 154
Do you perceive a drug addict more as a criminal or more as a patient?"
: (Crim "More as a criminal", pat "More as a patient", nei "Neither a criminal nor a patient",
both "Both a criminal and a patient", dontk "Don't know, cannot decide")
Ask if Q34 = Yes (Has heard of Cannabis)
Q155a
"SHOWCARD 155
To what extent do you agree with the following statements:
People should be permitted to take cannabis for medical reasons"
: (fa "Fully agree", La "Largely agree", Ne "Neither",
Ld "Largely disagree", Fd "Fully disagree")
Ask if Q34 = Yes (Has heard of Cannabis)
Q155b
"SHOWCARD 155
(To what extent do you agree with the following statements:)
People should be permitted to take cannabis for recreational reasons"
: (fa "Fully agree", La "Largely agree", Ne "Neither", Ld "Largely disagree",
Fd "Fully disagree")
Ask if Q79 = Yes (Has heard of heroin)
Q155c
"SHOWCARD 155
(To what extent do you agree with the following statements:)
People should be permitted to take heroin"
: (fa "Fully agree", La "Largely agree", Ne "Neither", Ld "Largely disagree",
Fd "Fully disagree")
Ask if Q45 = Yes (Has heard of ecstasy)
Q156a
"SHOWCARD 156
Individuals differ in whether or not they disapprove of people doing certain
things. I will mention a few things, which some people might do. Can you tell me
if you would not disapprove, disapprove or strongly disapprove when people do
any of these things:
Trying ecstasy once or twice?"
: (dnd "Do not disapprove",
dis "Disapprove", sdis "Strongly disapprove")
Ask if Q79 = Yes (Has heard of heroin)
Q156b
"SHOWCARD 156
(Individuals differ in whether or not they disapprove of people doing certain
any of these things:)
Trying heroin once or twice?"
50
Ask all

Q156c
"SHOWCARD 156
Smoking 10 cigarettes a day?"
Ask all
Q156d
"SHOWCARD 156
Having one or two drinks several times a week?"
Ask if Q34 = Yes (Has heard of cannabis)
Q156e
"SHOWCARD 156
Smoking cannabis occasionally?"
Ask all
Q157a
"SHOWCARD 157
Now I would like to know how much do you think that people risk harming
themselves, physically or in other ways, if they do certain things. I will again
mention a few things some people might do. Please tell me if you consider it to be
no risk, a slight risk, a moderate risk or a great risk, if people do such things:
Smoke one or more packs of cigarettes a day?"
: (nr "No risk", Sr "Slight risk", Mr "Moderate risk", Gr "Great risk")
Ask all
Q157b
"SHOWCARD 157
(Now I would like to know how much do you think that people risk harming
no risk, a slight risk, a moderate risk or a great risk, if people do such things:)
Have five or more drinks at the weekend?"
Ask if Q34 = Yes (Has heard of cannabis)
Q157c
"SHOWCARD 157
51

Smoke cannabis regularly?"
Ask if Q45 = Yes (Has heard of ecstasy)
Q157d
"SHOWCARD 157
Try ecstasy once or twice?"
Ask if Q62 = Yes (Has heard of crack)
Q157e
"SHOWCARD 157
Try crack once or twice?"
Ask if Q70 = Yes (Has heard of cocaine)
Q157f
"SHOWCARD 157
Try cocaine once or twice?"
52

EXTRA DRUGS QUESTIONS
Ask if Q9 = yes (Drinks alcohol) OR Q10 = yes (Has ever drunk alcohol) OR Q36 = yes (Has
taken cannabis) OR Q47 = yes (Has taken Ecstasy) OR Q72 = yes (Has taken cocaine) OR
Q153c = yes
Int158
"I'd like to ask you a few more questions about some of the substances you said
earlier that you had used"
: (Continue
Ask if Q9 = yes (Drinks alcohol) OR Q10 = yes (Has ever drunk alcohol)
Q158
"Earlier in the study you stated that you have drunk alcohol, have you ever drunk
alcohol regularly?"
: (Y "Yes", N "No")
Ask if (Q9 = yes (Drinks alcohol) OR Q10 = yes (Has ever drunk alcohol)) AND Q158 = yes
(has drunk alcohol regularly)
Q159
"Earlier in the study you stated the age when you first drank alcohol, ( age appears
on screen), can you tell us at what age you first drank alcohol regularly?"
:0..64
Ask if Q36 = yes (Has taken cannabis)
Q160
"Earlier in the study you stated that you have taken cannabis, have you ever taken
cannabis regularly?"
: (Y "Yes", N "No")
Ask if Q36 = yes (Has taken cannabis) AND Q160 = yes (Has taken cannabis regularly)
Q161
"Earlier in the study you stated the age when you first took cannabis, (age
appears on screen), can you tell us at what age did you first take cannabis
regularly?"
: 0..64
Ask if Q36 = yes (Has taken cannabis) AND Q160 = yes (Has taken cannabis regularly)
Q162
"SHOWCARD 162
Have you ever tried to stop taking cannabis"
: (ys "Yes - tried to and stopped", yns "Yes - tried to but not stopped", No)
Ask if Q36 = yes (Has taken cannabis) AND Q160 = yes (Has taken cannabis regularly) AND
(Q162 = ys OR yns (Tried to stop taking cannabis))
Q163
"SHOWCARD 163
What was the main reason for (textfill – if Q162 = ys “stopping”, if Q162 = yns
“trying to stop”) taking cannabis?
CODE ONE ONLY"
:(
Cost "Cost/could not afford it",
family "Persuaded by friends/family",
impact "Impact on job/friends/family",
social "No longer part of social life",
health "Concern about health/health reasons",
pregnancy "Pregnancy",
supply "Less available supply",
rehab "Put on rehabilitation programme",
53

nowant "Did not want to take anymore",
effects "Did not enjoy after effects",
pros "The pros of taking did not outweigh the cons",
Ask if Q36 = yes (Has taken cannabis) AND Q160 = yes (Has taken cannabis regularly) AND
(Q162 = ys OR yns (Tried to stop taking cannabis)) AND Q163 = other (another main reason
for stopping/trying to stop taking cannabis)
Spec163
"What was the other reason for (textfill – if Q162 = ys “stopping”, if Q162 = yns
“trying to stop”) taking cannabis?"
: STRING [255]
Ask if Q47 = yes (Has taken Ecstasy)
Q164
"Earlier in the study you stated that you have taken ecstasy, have you ever taken
ecstasy regularly?"
: (Y "Yes", N "No")
Ask if Q47 = yes (Has taken Ecstasy) AND Q164 = yes (Has taken ecstasy regularly)
Q165
"Earlier in the study you stated the age when you first took ecstasy, ( age appears
on screen), can you tell us at what age did you first take ecstasy regularly?"
: 0..64
Ask if Q47 = yes (Has taken Ecstasy) AND Q164 = yes (Has taken ecstasy regularly)
Q166
"SHOWCARD 166
Have you ever tried to stop taking ecstasy?"
:(ys "Yes - tried to and stopped", yns "Yes - tried to but not stopped", No)
Ask if Q47 = yes (Has taken Ecstasy) AND Q164 = yes (Has taken ecstasy regularly) AND
(Q166 = ys OR yns (Has tried to stop taking ecstasy))
Q167
"SHOWCARD 167
“trying to stop”) taking ecstasy?
CODE ONE ONLY"
:(
Ask if Q47 = yes (Has taken Ecstasy) AND Q164 = yes (Has taken ecstasy regularly) AND
(Q166 = ys OR yns (Has tried to stop taking ecstasy)) AND Q167 = other (another reason for
stopping/trying to stop taking ecstasy)
Spec167
“trying to stop”) taking ecstasy?"
54

: STRING [255]
Ask if Q72 = yes (Has taken cocaine)
Q168
"Earlier in the study you stated that you have taken cocaine, have you ever taken
cocaine regularly?"
: (Y "Yes", N "No")
Ask if Q72 = yes (Has taken cocaine) AND Q168 = yes (Has taken cocaine regularly)
Q169
"Earlier in the study you stated the age when you first took cocaine, ( age appears
on screen), can you tell us at what age did you first take cocaine regularly?"
: 0..64
Ask if Q72 = yes (Has taken cocaine) AND Q168 = yes (Has taken cocaine regularly)
Q170
"SHOWCARD 170
Have you ever tried to stop taking cocaine?"
Ask if Q72 = yes (Has taken cocaine) AND Q168 = yes (Has taken cocaine regularly) AND
(Q170 = ys OR yns (Has tried to stop taking cocaine))
Q171
"SHOWCARD 171
“trying to stop”) taking cocaine?
CODE ONE ONLY"
:(
Ask if Q72 = yes (Has taken cocaine) AND Q168 = yes (Has taken cocaine regularly) AND
(Q170 = ys OR yns (Has tried to stop taking cocaine)) AND Q171 = other (Another main
reason for stopping/trying to stop taking cocaine)
Spec171
“trying to stop”) taking cocaine?"
: STRING [255]
Ask if Q153c = yes (Has taken mephedrone)
Q171a
"Earlier in the study you stated that you have taken mephedrone, have you ever
taken mephedrone regularly?"
: (Y "Yes", N "No")
Ask if Q153c= yes (Has taken mephedrone) AND Q171a = yes (Has taken mephedrone
regularly)
55

Q171b
"SHOWCARD 171b
Have you ever tried to stop taking mephedrone"
Ask if Q153c = yes (Has taken mephedrone) AND Q171a = yes (Has taken mephedrone
regularly) AND (Q171b = ys (Stopped) OR yns (Tried to stop taking mephedrone))
Q171c
"Did you (textfill – if Q171b = ys “stop”,) or (textfill - if Q171b = yns “try to stop”)
taking mephedrone because it was made illegal?"
: (Y "Yes", N "No")
Ask if Q39 = yes (Has taken cannabis in the past 12 months)
Q172
"SHOWCARD 172
How did you get the cannabis on the last occasion you used it?
CODE ONE ONLY"
: (family "Given by family/friend",
contact "Given by a contact I did not know personally",
stranger "Given by a stranger",
friends "Shared amongst group of friends",
bought "Bought from a friend",
bcon "Bought from a contact I did not know personally",
bstra "Bought from a stranger",
Ask if Q39 = yes (Has taken cannabis in the past 12 months) AND Q172 = other (got
cannabis another way last occasion used it)
Spec172
"What was the other way you got the cannabis on the last occasion you used it?"
: STRING [255]
Q173
"SHOWCARD 173
In which of the following places did you obtain the cannabis on the last occasion
you used it?
CODE ONE ONLY"
: (Street "Street/park",
Disco "Disco/bar/club",
Office "Office/workplace",
School "School/college",
dealer "House of a dealer",
friend "House of a friend",
phone "Ordered by phone for collection/delivery",
inter "Internet",
Ask if Q39 = yes (Has taken cannabis in the past 12 months) AND Q173 = other (obtained
cannabis from another place on last occasion used it)
Spec173
"What was the other place you obtained the cannabis from on the last occasion
you used it?"
: STRING [255]
56

Q174
"SHOWCARD 174
How easy or difficult is to obtain cannabis in a 24-hour period?
Just call me out the number from the card"
: ( ve "Very easy", fe "Fairly easy" Nend "Neither easy nor difficult", Fd "Fairly difficult",
Vd "Very difficult")
Ask if Q50 = yes (Has taken ecstasy in the past 12 months)
Q175
"SHOWCARD 175
How did you get the ecstasy on the last occasion you used it?
CODE ONE ONLY"
: (family "Given by family/friend",
Ask if Q50 = yes (Has taken ecstasy in the past 12 months) AND Q175 = other (Another way
of getting ecstasy on the last occasion used it)
Spec175
"What was the other way you got the ecstasy on the last occasion you used it?"
: STRING [255]
Q176
"SHOWCARD 176
In which of the following places did you obtain the ecstasy on the last occasion
you used it?
CODE ONE ONLY"
:(Street "Street/park", Disco "Disco/bar/club", Office "Office/workplace",School
"School/college",
inter "Internet",
Ask if Q50 = yes (Has taken ecstasy in the past 12 months) AND Q176 = other (obtained
ecstasy in another place on the last occasion used it)
Spec176
"What was the other place you obtained the ecstasy from on the last occasion you
used it?"
: STRING [255]
Q177
"SHOWCARD 177
How easy or difficult is to obtain ecstasy in a 24-hour period?
: ( ve "Very easy",
fe "Fairly easy" Nend "Neither easy nor difficult",
Fd "Fairly difficult",
57

Ask if Q75 = yes (Has taken cocaine in the past 12 months)
Q178
"SHOWCARD 178
How did you get the cocaine on the last occasion you used it?
CODE ONE ONLY"
:(family "Given by family/friend",
Ask if Q75 = yes (Has taken cocaine in the past 12 months) AND Q178 = other (Another way
of getting cocaine on last occasion used it)
Spec178
"What was the other way you got the cocaine on the last occasion you used it?"
: STRING [255]
Q179
"SHOWCARD 179
In which of the following places did you obtain the cocaine on the last occasion
you used it?
CODE ONE ONLY"
:(Street "Street/park",
Disco "Disco/bar/club",
Office "Office/workplace",
School "School/college",
inter "Internet",
Ask if Q75 = yes (Has taken cocaine in the past 12 months) AND Q179 = Other (Obtained
cocaine in another place on last occasion)
Spec179
"What was the other place you obtained the cocaine from on the last occasion you
used it?"
: STRING [255]
Q180
"SHOWCARD 180
How easy or difficult is to obtain cocaine in a 24-hour period?
: ( ve "Very easy",
fe "Fairly easy"
Nend "Neither easy nor difficult",
Fd "Fairly difficult",
58

CLASSIFICATORY QUESTIONS
Ask all
MarStt
"Are you/is ^Name
RUNNING PROMPT - CODE FIRST THAT APPLIES"
"Ask as a running prompt and keep strictly to the order indicated.
: (single "Single, that is never married",
married "Married and living with husband\wife",
civilpa "a civil partner in a legally-recognised Civil Partnership",
sep
"Married and separated from husband\wife",
divorced "Divorced",
widowed "Widowed",
cpsep
"Spontaneous only - In a legally-recognised Civil Partnership and separated
from his/her civil partner",
cpdis
"Spontaneous only - Formerly a civil partner, the Civil Partnership now legally
dissolved",
cpwid "Spontaneous only - A surviving civil partner: his/her partner having since died")
Ask if Marstt <> married (not married) OR Marstt <> civilpa (not civil partner) AND 16 years
old or over AND there is more than 1 adult in the household.
LivTog
"ASK OR RECORD
May I just check, are you currently living with someone in this household as a
couple?
: (Y "Yes", N "No",
SamSex "same sex couple (but not in a formal registered Civil Partnership)")
Ask all
Relhrp
ASK OR RECORD
Relationship of <name> TO Household Reference Person
NOTE THAT PERSON 1 SHOULD ALWAYS BE HRP
"The HOUSEHOLD REFERENCE PERSON must by definition be a member of the
household, and is the person (in order of precedence) who owns the household
accommodation OR is legally responsible for the rent OR has the responsibility for
the accommodation. If none of the above apply (e.g. a separated woman or joint
owners), the HRP is the person whom the adults agree to be the HRP. Generally it
is the husband, or the elder of 2 persons of the same sex. In the case of a single
person sharing (eg students, unmarried employees, etc.), it is the person who is
legally responsible for the accommodation/rent/contract/etc."
: (HRP "Household Reference Person",
Spouse,
Cohab "Cohabiting partner",
child "Son/daughter (incl.adopted)",
stepsd "Step-son/daughter",
fostch "Foster child",
soninl "Son-in-law/Daughter-in-law",
parg "Parent/guardian",
stepp "Step-parent",
fostp "Foster Parent",
parinl "Parent-in-law",
broths "Brother/sister (incl. adopted)",
stepbs "Step-brother/sister",
fostbs "Foster brother/sister",
brotsi "Brother/sister-in-law",
grandc "Grand-child",
grandp "Grand-parent",
59

othrel "Other relative",
othnre "Other non-relative",
CPartner "Civil Partner")
Ask all
HousTen
"SHOW CARD 1 (TENURE)
In which of these ways do you occupy this accommodation?"
: (ownout "Own it outright",
mortloan "Buying it with the help of a mortgage or loan",
coown "Pay part rent and part mortgage (co-ownership)",
housexec "Rented from Housing Executive",
housasst "Rented from a housing association",
private "Rented privately",
rentfree "Live here rent free",
squattin "Squatting")
Ask if housten = private (rents privately)
Rent
"Is your rent collected by the landlord or an agent?
AN AGENT IS A THIRD PARTY PAID TO COLLECT RENT FROM TENANTS
: (landlrd "the landlord", agent "an agent") ;
Ask if housten = private (rents privately) OR housten = rentfree (Lives rent free)
landlord
"Who is your landord?
RUNNING PROMPT - CODE FIRST THAT APPLIES"
: (employ "employer (organisation) of a household member",
othorg "another organisation",
relat "relative/friend (before you lived here) of a household member",
empli "employer (individual) of a household member",
othind "another individual private landlord?"
Ask if ((Rent = landlrd (Landlord collects the rent)) OR (Rent = agent (agent collects the
rent)) OR (Rent = DONTKNOW (doesn’t know who collects the rent)) OR (HousTen =
HousExec (rents from housing executive)) OR (HousTen = HousAsst (rents from a housing
association)))
Scheme
"Is this property part of a sheltered accommodation scheme?"
: (Y "Yes", N "No")
Ask if ((HousTen = Rentfree (Lives rent free)) OR (Scheme = Yes (part of a sheltered
accommodation scheme)) OR (Scheme = No (not part of sheltered accommodation scheme))
Furnish
"Is the accommodation provided: furnished, partly furnished, or unfurnished?”
CODE 2 IF SOME FURNITURE PROVIDED BUT NOT THE BASIC NECESSITIES"
"Rented furnished or unfurnished?"
: (Furnsh "furnished", Unpart "partly furnished", unfurn "Unfurnished");
Ask if ((HousTen = Rentfree (Lives rent free)) OR (Scheme = Yes (Part of a sheltered
accommodation scheme)) OR (Scheme = No (not part of a sheltered accommodation
scheme)) AND ((Furnish = Furnsh (accommodation is furnished)) OR (Furnish = Unpart
(accommodation is partly furnished))) or (Furnish = Unfurn(accommodation is unfurnished)))
Business
"Are any business premises included in the rent for this accommodation (in the
accommodation provided)?
INCLUDE FARM"
60

: (Y "Yes", N "No")
Ask if ((HousTen = HousAsst (rents from a housing association)) OR (HousTen = Private
(rents privately)) OR (HousTen =Rentfree (Lives rent free)))
Accjob
"Can I just check, does the accommodation go with the job of anyone in the
household?"
: (Y "Yes", N "No")
Ask all
Child “How many children, including children aged 16-18 in full time education,
are dependent on you?"
:0..50
Ask if Child > 0 (more than one dependent child)
Childage "What is the age of your youngest dependent child?
STATE EXACT AGE"
:0..18
Ask all
Dep
"In this household, do you care for an adult who requires substantial assistance
with the activities of daily living?"
: (Y "Yes", N "No")
Ask if Dep = no (does not care for an adult in the household)
Carer
"ASK OR RECORD
Do you look after or give any help or support to family members, friends,
neighbours or others because of long-term physical or mental health or disability
or problems related to old age?"
: (Y "Yes", N "No")
Ask if Dep = yes (cares for an adult in the household) OR carer = yes (looks after others)
Hours
"How may hours a week would you say you spend doing this..."
: (ONE "1-19 hours a week", TWE "20-49 hours a week",
FIF "Fifty hours or more per
week?")
Ask all
disab
"And may I just ask, do you have any long-term illness, health problem or
disability which limits your daily activities or the work you can do?"
: (Y "Yes",
N "No")
Ask if respondent is not HRP
Hrpjob
"Does the household reference person, <textfill – name of HRP>, have a paid job
full-time or part-time?"
: (Y "Yes", N "No")
Ask if respondent is not HRP AND HRPJob = no (HRP does not have a paid job full-time or
part-time)
C14
"SHOWCARD H3
Looking at this card, please tell me the statement that best describes the HRP,
<textfill – name of HRP>. Just read out the letter of the one that best applies"
61

: (A "A-Retired, gets pension from previous job",
B "B-Unemployed less than 2 months",
C "C-Sick, still receiving pay or statutory pay from job",
D "D-widowed, receiving pension from spouse's previous job",
E "E-Divorced/separated, receiving maintenance",
F "Full-time student",
G "Not working, private means",
H "Unemployed - longer than 2 months",
I "Sick - only receiving Income Support or Invalidity Benefit",
J "Receiving State Pension only")
Ask if respondent is not HRP AND (C14 = A (HRP is retired, gets pension from previous job)
OR C14 = B (HRP is unemployed for less than 2 months) OR C14 = C (HRP is sick, still
receiving pay or statutory pay from job) OR C14 = D (HRP is widowed, receiving pension
from spouse’s previous job) OR C14 = E (HRP is divorced/separated, receiving maintenance)
OR HRPjob = YES (HRP has a paid job full-time or part-time))
C15a
"What type of firm/organisation does/did <textfill – name of HRP or HRP‟s
spouse> work for?"
: STRING
C15b
"What job does/did <textfill, name of HRP or HRP‟s spouse> do?"
:STRING
Ask if respondent is not HRP AND ( C14 = A (HRP is retired, gets pension from previous job)
C15c
"Does/Did <textfill, name of HRP or HRP‟s spouse> have any position/rank/grade
in the organisation (i.e., responsible for the work of other people)?"
: (Y "Yes", N "No")
OR HRPjob = YES (HRP has a paid job full-time or part-time)) AND C15c = yes (HRP OR
HRP’s spouse was responsible for the work of other people)
C15d
"What position/rank/grade did <textfill, name of HRP or HRP‟s spouse> have in
the organisation?
INTERVIEWER: PROMPT AS APPROPRIATE (FOREMAN, SERGEANT, OFFICE
MANAGER, EXECUTIVE, OFFICER ETC)"
:STRING
62

OR HRPjob = YES (HRP has a paid job full-time or part-time)) AND C15c = yes (HRP OR
HRP’s spouse was responsible for the work of other people)
C15E
"How many people is/was <textfill, name of HRP or HRP‟s spouse> responsible
for?"
:0..1000000
from spouse’s previous job) OR C14 = E (HRP is divorced/separated, receiving maintenance
OR C14 = refused OR C14 = Don’t Know) OR HRPjob = YES (HRP has a paid job full-time or
part-time))
C15F
"Does/Did <textfill, name of HRP or HRP‟s spouse> have any qualifications?"
: (Y "Yes", N "No")
from spouse’s previous job) OR C14 = E (HRP is divorced/separated, receiving maintenance
OR C14 = refused OR C14 = Don’t Know) OR HRPjob = YES (HRP has a paid job full-time or
part-time)) AND C15F = yes (HRP or HRP’s spouse does have qualifications)
C15g
"SHOWCARD C15g
What qualifications does/did <textfill, name of HRP or HRP‟s spouse> have?"
: SET [10] OF
( CSEG1
"CSE - Grade 1",
CSEG2_5
"CSE - Grade 2-5",
CSE_ug
"CSE - ungraded\DK grade",
Junior
"Junior certificate",
GCSEa_c
"GCSE - Grades A-C\GNVQ Intermediate",
GCSEd_g
"GCSE - Grades D-G\GNVQ Foundation",
GCEO1_6
"GCE O-level 1-6 (pre-1975)",
GCEOa_c
"GCE O-level A-C (1975 or after)",
AS
"AS - level",
GCEA
"GCE A-level or equivalent\GNVQ Advanced or equivalent",
Senior
"Senior Certificate",
Apprent
"Recognised apprenticeship completed",
Clercom
"Clerical and commercial quals",
NCVQI
"National Council for Vocational Qualifications award - level one",
NCVQII
"National Council for Vocational Qualifications award - level two",
NCVQIII
"National Council for Vocational Qualifications award - level three",
NCVQIV
"National Council for Vocational Qualifications award - level four",
NCVQV
"National Council for Vocational Qualifications award - level five",
VCE
"Vocational Certificate in Education",
AVCE
"Advanced Vocational Certificate in Education",
CityGI
"City and Guilds Cert Part I",
CityGII
"City and Guilds Cert Part II",
CityGIII
"City and Guilds Cert Part III",
ONCD_BEC "ONC\OND, BEC\TEC general cert",
HNCD_BEC "HNC\HND, BEC\TEC higher cert",
Nursing
"Nursing quals eg SEN, SRN, SCM",
Nursdeg
"Nursing degree",
Teach
"Teaching qualifications",
Unidip
"University\Polytechnic diploma",
Degree
"University or CNAA First Degree (eg BA BSc)",
Hideg
"University or CNAA Higher Degree (eg MSc PhD)",
63

other
NONE
"Other qualification (inc other school exams and membership of professional
institutions)",
"NONE OF THESE")
stillsch
“I would like to ask you a few questions about your education. ASK OR RECORD IF
CERTAIN - Is respondent still at school? (Elementary, Secondary or Grammar)”:
(still “Still at school”, left “left school”, never “never went to school”)
Ask if stillsch=left
C16b “At what age did you finish your full time education?”
: 0..100
Introa
"Introduction to Income Section
We're now onto the last few questions. I would like to as you about YOUR income.
This will help ensure the survey is representative of all households across
Northern Ireland."
:(CONTINUE)
Ask if empst = atwork (worked last week) OR empst = awaywork (was away from work last
week)
grossper
"SHOWCARD C1
Which of the following numbers represents YOUR own annual gross or total
EARNINGS before deduction of income tax and National Insurance contributions?"
: (A "Less than £520 per year, say less than £10 per week",
B "£520 less than £1,040 per year, say £10 less than £20 per week",
C "£1,040 less than £1,560 per year, say £20 less than £30 per week",
D "£1,560 less than £2,080 per year, say £30 less than £40 per week",
E "£2,080 less than £2,600 per year, say £40 less than £50 per week",
F "£2,600 less than £3,120 per year, say £50 less than £60 per week",
G "£3,120 less than £3,640 per year, say £60 less than £70 per week",
H "£3,640 less than £4,160 per year, say £70 less than £80 per week",
I "£4,160 less than £4,680 per year, say £80 less than £90 per week",
J "£4,680 less than £5,200 per year, say £90 less than £100 per week",
K "£5,200 less than £6,240 per year, say £100 less than £120 per week",
L "£6,240 less than £7,280 per year, say £120 less than £140 per week",
M "£7,280 less than £8,320 per year, say £140 less than £160 per week",
N "£8,320 less than £9,360 per year, say £160 less than £180 per week",
O "£9,360 less than £10,400 per year, say £180 less than £200 per week",
P "£10,400 less than £11,440 per year, say £200 less than £220 per week",
Q "£11,440 less than £12,480 per year, say £220 less than £240 per week",
R "£12,480 less than £13,520 per year, say £240 less than £260 per week",
S "£13,520 less than £14,560 per year, say £260 less than £280 per week",
T "£14,560 less than £15,600 per year, say £280 less than £300 per week",
U "£15,600 less than £16,640 per year, say £300 less than £320 per week",
V "£16,640 less than £17,680 per year, say £320 less than £340 per week",
W "£17,680 less than £18,720 per year, say £340 less than £360 per week",
X "£18,720 less than £19,760 per year, say £360 less than £380 per week",
Y "£19,760 less than £20,800 per year, say £380 less than £400 per week",
Z "£20,800 less than £23,400 per year, say £400 less than £450 per week",
AA"£23,400 less than £26,000 per year, say £450 less than £500 per week",
BB"£26,000 less than £28,600 per year, say £500 less than £550 per week",
CC"£28,600 less than £31,200 per year, say £550 less than £600 per week",
DD"£31,200 less than £33,800 per year, say £600 less than £650 per week",
EE"£33,800 less than £36,400 per year, say £650 less than £700 per week",
FF"£36,400 or more per year, say £700 per week or more")
64

Ask if ( empst = atwork (worked last week) OR empst = awaywork (was away from work last
week)) AND grossper = FF (own annual gross or total EARNINGS before deduction of income
tax and National Insurance contributions £36,400 or more per year)
grosper
SHOWCARD C2
SHOW RESPONDENT ADDITIONAL SHOWCARD AND ASK THEM AGAIN IF THEY
CAN SPECIFY THEIR GROSS EARNINGS"
: (A "£36,400 less than £37,000",
B "£37,000 less than £38,000",
C "£38,000 less than £39,000",
D "£39,000 less than £40,000",
E "£40,000 less than £41,000",
F "£41,000 less than £42,000",
G "£42,000 less than £43,000",
H "£43,000 less than £44,000",
I "£44,000 less than £45,000",
J "£45,000 less than £46,000",
K "£46,000 less than £47,000",
L "£47,000 less than £48,000",
M "£48,000 less than £49,000",
N "£49,000 less than £50,000",
O "£50,000 less than £55,000",
P "£55,000 less than £60,000",
Q "£60,000 less than £65,000",
R "£65,000 less than £70,000",
S "£70,000 less than £75,000",
U "£75,000 less than £80,000",
V "£80,000 less than £85,000",
W "£85,000 less than £90,000",
X "£90,000 less than £95,000",
Y "£95,000 less than £100,000",
Z "£100,000 less than £105,000",
AA"£105,000 less than £110,000",
BB"£110,000 less than £115,000",
CC"£115,000 less than £120,000",
DD"£120,000 less than £125,000",
EE"£125,000 less than £130,000",
FF"£130,000 less than £135,000",
GG"£135,000 less than £140,000",
HH"£140,000 less than £145,000",
II"£145,000 less than £150,000",
JJ"£150,000 less than £155,000",
KK"£155,000 less than £160,000",
LL"£160,000 less than £165,000",
MM"£165,000 less than £170,000",
NN"£170,000 less than £175,000",
OO"£175,000 less than £180,000",
PP"£180,000 less than £185,000",
QQ"£185,000 less than £190,000",
RR"£190,000 less than £195,000",
SS"£195,000 less than £200,000",
TT"£200,000 less than £210,000",
UU"£210,000 less than £220,000",
VV"£220,000 less than £230,000",
WW"£230,000 less than £240,000",
XX"£240,000 less than £250,000",
YY"£250,000 less than £260,000",
65

ZZ"£260,000 less than £270,000",
AB"£270,000 less than £280,000",
BC"£280,000 less than £290,000",
CD"£290,000 less than £300,000",
EF"£300,000 less than £320,000",
FG"£320,000 less than £340,000",
GH"£340,000 less than £360,000",
HI"£360,000 less than £380,000",
IJ"£380,000 less than £400,000",
JK"£400,000 or more")
Ask all
grosspir
"SHOWCARD C1
Which of the following numbers represents YOUR own annual gross or total
income FROM ALL SOURCES before deduction of income tax and National
Insurance contributions?"
Ask if grosspir = FF (YOUR own annual gross or total income FROM ALL SOURCES before
deduction of income tax and National Insurance contributions is £36,400 or more per year)
grospir
"SHOWCARD C2
CAN SPECIFY THEIR GROSS INCOME FROM ALL SOURCES"
: (A "£36,400 less than £37,000",
66

B "£37,000 less than £38,000",
C "£38,000 less than £39,000",
D "£39,000 less than £40,000",
E "£40,000 less than £41,000",
F "£41,000 less than £42,000",
G "£42,000 less than £43,000",
H "£43,000 less than £44,000",
I "£44,000 less than £45,000",
J "£45,000 less than £46,000",
K "£46,000 less than £47,000",
L "£47,000 less than £48,000",
M "£48,000 less than £49,000",
N "£49,000 less than £50,000",
O "£50,000 less than £55,000",
P "£55,000 less than £60,000",
Q "£60,000 less than £65,000",
R "£65,000 less than £70,000",
S "£70,000 less than £75,000",
U "£75,000 less than £80,000",
V "£80,000 less than £85,000",
W "£85,000 less than £90,000",
X "£90,000 less than £95,000",
Y "£95,000 less than £100,000",
Z "£100,000 less than £105,000",
AA"£105,000 less than £110,000",
BB"£110,000 less than £115,000",
CC"£115,000 less than £120,000",
DD"£120,000 less than £125,000",
EE"£125,000 less than £130,000",
FF"£130,000 less than £135,000",
GG"£135,000 less than £140,000",
HH"£140,000 less than £145,000",
II"£145,000 less than £150,000",
JJ"£150,000 less than £155,000",
KK"£155,000 less than £160,000",
LL"£160,000 less than £165,000",
MM"£165,000 less than £170,000",
NN"£170,000 less than £175,000",
OO"£175,000 less than £180,000",
PP"£180,000 less than £185,000",
QQ"£185,000 less than £190,000",
RR"£190,000 less than £195,000",
SS"£195,000 less than £200,000",
TT"£200,000 less than £210,000",
UU"£210,000 less than £220,000",
VV"£220,000 less than £230,000",
WW"£230,000 less than £240,000",
XX"£240,000 less than £250,000",
YY"£250,000 less than £260,000",
ZZ"£260,000 less than £270,000",
AB"£270,000 less than £280,000",
BC"£280,000 less than £290,000",
CD"£290,000 less than £300,000",
EF"£300,000 less than £320,000",
FG"£320,000 less than £340,000",
GH"£340,000 less than £360,000",
HI"£360,000 less than £380,000",
IJ"£380,000 less than £400,000",
67

JK"£400,000 or more")
benefits
"Are you at present receiving any State Benefits?"
:yesno
typeben
"SHOW CARD C3 (BENEFITS)
CODE ALL THAT APPLY
Which of the following benefits do you receive…"
: SET OF
(childben "Child Benefit",
retire "Retirement Pension or Old Age Pension",
pencrd "Pension Credit",
incsupp "Income support",
jsa "Job Seekers Allowance (INCOME BASED)",
unempben "Job Seekers Allowance (CONTRIBUTORY) (was Unemployment Benefit)",
esa “Employment & Support Allowance”,
sickben "Incapacity Benefit / Youth Incapacity Benefit",
attall "Attendance Allowance",
dlacare "Disability Living Allowance (Care Component)",
dlamob “Disability Living Allowance (Mobility Component),
Invalid "Carer's Allowance (was Invalid Care Allowance)",
widows "Widow's Pension, War Widow's Pension, Bereavement Benefit (includes
Bereavement Allowance and/or Bereavement Payment) or Widowed Parent's (Widowed
Mother's Allowance)",
matern "Maternity Allowance",
sevdis "Severe Disablement Allowance",
socfund "Social Fund Loan",
iib
"Industrial Injuries Benefit (i.e. Industrial Death Benefit, Industrial Injuries Disablement
Benefit or Reduced Earnings Allowance)",
none "None of above");
Ask if more than one person in the household
grosshh
"SHOWCARD C1
Which number represents the TOTAL gross annual income FROM ALL SOURCES of
your HOUSEHOLD?"
"Total income is obtained by summing the components of earnings, benefits,
pensions, dividends, interest, and other regular payments"
68

Ask if more than one person in the household and grosshh = FF (the TOTAL gross annual
income FROM ALL SOURCES of HOUSEHOLD £36,400 or more per year)
groshh
"SHOWCARD C2
CAN SPECIFY THEIR HOUSEHOLD INCOME FROM ALL SOURCES"
: (A "£36,400 less than £37,000",
B "£37,000 less than £38,000",
C "£38,000 less than £39,000",
D "£39,000 less than £40,000",
E "£40,000 less than £41,000",
F "£41,000 less than £42,000",
G "£42,000 less than £43,000",
H "£43,000 less than £44,000",
I "£44,000 less than £45,000",
J "£45,000 less than £46,000",
K "£46,000 less than £47,000",
L "£47,000 less than £48,000",
M "£48,000 less than £49,000",
N "£49,000 less than £50,000",
O "£50,000 less than £55,000",
P "£55,000 less than £60,000",
Q "£60,000 less than £65,000",
R "£65,000 less than £70,000",
S "£70,000 less than £75,000",
U "£75,000 less than £80,000",
V "£80,000 less than £85,000",
W "£85,000 less than £90,000",
X "£90,000 less than £95,000",
Y "£95,000 less than £100,000",
Z "£100,000 less than £105,000",
AA"£105,000 less than £110,000",
BB"£110,000 less than £115,000",
CC"£115,000 less than £120,000",
DD"£120,000 less than £125,000",
EE"£125,000 less than £130,000",
FF"£130,000 less than £135,000",
GG"£135,000 less than £140,000",
HH"£140,000 less than £145,000",
II"£145,000 less than £150,000",
JJ"£150,000 less than £155,000",
KK"£155,000 less than £160,000",
LL"£160,000 less than £165,000",
69

MM"£165,000 less than £170,000",
NN"£170,000 less than £175,000",
OO"£175,000 less than £180,000",
PP"£180,000 less than £185,000",
QQ"£185,000 less than £190,000",
RR"£190,000 less than £195,000",
SS"£195,000 less than £200,000",
TT"£200,000 less than £210,000",
UU"£210,000 less than £220,000",
VV"£220,000 less than £230,000",
WW"£230,000 less than £240,000",
XX"£240,000 less than £250,000",
YY"£250,000 less than £260,000",
ZZ"£260,000 less than £270,000",
AB"£270,000 less than £280,000",
BC"£280,000 less than £290,000",
CD"£290,000 less than £300,000",
EF"£300,000 less than £320,000",
FG"£320,000 less than £340,000",
GH"£340,000 less than £360,000",
HI"£360,000 less than £380,000",
IJ"£380,000 less than £400,000",
JK"£400,000 or more")
Ask all
AgeDob
"May I just check..
What is your date of birth?
IF DAY IS NOT KNOWN OR REFUSED, ENTER 15 FOR DAY
IF MONTH IS NOT KNOWN OR REFUSED, ENTER 6 FOR MONTH
IF YEAR IS NOT KNOWN OR REFUSED, ENTER DK OR REF:
:DATETYPE
Ask all
denomin
"INTRODUCE - I would like to ask you now about religion.
What is your religion, even if you are not currently practising?"
: (Cath "Catholic",
Pres "Presbyterian",
CoI
"Church of Ireland",
Meth "Methodist"
Bapt "Baptist",
FreeP "Free Presbyterian",
Breth "Brethren",
ProtNS "Protestant - not specified",
OtherC "Other Christian",
Budd "Buddhist"
Hindu "Hindu"
Jew
"Jewish",
Mus
"Muslim"
Sikh "Sikh",
Other "Any other religion (please describe)",
none "No Religion");
IF denomin = other
othdenom
"Please describe this other religion"
: string[100]
70

IF Denomin <> None
relpract
"Do you consider that you are actively practising your religion?"
: (Y "Yes", N "No")
IF Denomin <> None
attend
"And how often do attend your place of worship?"
(Morewk "More than once a week",
Leastwk "At least once a week",
Leastfn "At least once a fortnight",
Leastmth "At least once a month",
twomon "At least once every few months",
Leastyr "At least once a year",
Less
"Less often",
Never
"Never",
Unable "Unable to attend");
Ask all
ethnic
"SHOWCARD C4
To which one of these ethnic groups do you consider you belong?"
:( WhtBrit "White",
IrishTrv "Irish Traveller",
WhtOth
"Any other white background (please describe)",
MixedWBC "Mixed - White and Black Caribbean",
MixedWBA "Mixed - White and Black African",
MixedWAs "Mixed - White and Asian",
MixedOth "Any other mixed background (please describe)",
Indian
"Asian - Indian",
Pakistan "Asian - Pakistani",
Bngldesh "Asian - Bangladeshi",
AsianOth "Any other Asian background (please describe)",
BlackCrb "Black - Caribbean",
BlackAfr "Black - African",
BlackOth "Any other Black background (please describe)",
Chinese,
Other
"Any other (please describe)")
Ask if ethnic = WhtOth or AsianOth or BlackOth or Other
EthOth
"Please can you describe your ethnic group.
INTERVIEWER: Enter description of ethnic group."
: STRING[100]
71
Ask all

Tele
"A few interviews in any survey are checked by Head Office to make sure that
people like yourself are satisfied with the way the interview was carried out. Just
in case yours is one of the interviews that is checked, it would be helpful if we
could have your telephone number.”
INTERVIEWER: If given, type the telephone number here including the area code.
If not given just press ENTER to continue.
PLEASE NOTE: If respondent is not the HRP or spouse please ask the respondent
to double-check with them that it is ok to provide us with their landline telephone
number"
:STRING[20],EMPTY
Telename
ASK OR RECORD
“And who should Head Office ask for?”
INTERVIEWER: If you have the respondents name from the household grid then
just record this. If not, can you ask the respondents for their first name.
If telephone number not given just press ENTER to continue"
: STRING [50],EMPTY
NoTelep
"Head Office may contact you in writing or face-to-face to make sure that you
were satisfied with the way the interview was carried out."
: (CONTINUE)
Ask all
Thanks
"Thank you very much for your time and for agreeing to take part in this survey."
: (Continue
Ask if respondent is under 16
parpres
"INTERVIEWER
Was there a parent or guardian present during the interview"
: (Y "Yes", Fs "Yes, for some of the interview", N "No")
72

B. SHOWCARDS
Drug Prevalence Survey
2010/11
SHOW CARDS
73

SHOW CARD „H1‟
1
Own it outright
2
Buying it with the help of a mortgage or loan
3
Pay part rent and part mortgage (co-ownership)
4
Rented from Housing Executive
5
Rented from a Housing Association
6
Rented privately
7
Live here rent free
8
Squatting
74

SHOW CARD „H2‟
1
CSE - Grade 1
2
CSE - Grade 2-5
3
CSE - ungraded/DK Grade
4
Junior Certificate
5
GCSE - Grades A-C/GNVQ Intermediate
6
GCSE - Grades D-G/GNVQ Foundation
7
GCE O-Level 1-6 (pre 1975)
8
GCE O-Level A-C (1975 or after)
9
AS Level
10
GCE A-Level or equivalent/GNVQ Advanced or Equivalent
11
Senior Certificate
12
Recognised apprenticeship completed
13
Clerical and commercial quals
14
National Council for Vocational Qualifications award - level one
15
National Council for Vocational Qualifications award - level two
16
National Council for Vocational Qualifications award - level three
17
National Council for Vocational Qualifications award - level four
18
National Council for Vocational Qualifications award - level five
19
Vocational Certificate in Education
20
Advanced Vocational Certificate in Education
21
City and Guilds Cert Part I
22
City and Guilds Cert Part II
23
City and Guilds Cert Part III
24
ONC/OND, BEC/TEC General Cert
25
HNC/HND, BEC/TEC Higher Cert
26
Nursing quals, eg SEN, SRN, SCM
27
Nursing Degree
28
Teaching Qualifications
29
University/Polytechnic Diploma
30
University or CNAA First Degree (eg BA, BSc)
31
University or CNAA Higher Degree (eg MSc, PhD)
32
Other qualifications (including other school exams and
membership of professional institutions)
33
NONE OF THESE
75

SHOW CARD „H3‟
1
2
Retired, gets pension from previous job
Unemployed less than 2 months
3
Sick, still receiving pay or statutory pay from job
4
Widowed, receiving pension from spouse‟s previous job
5
Divorced/separated, receiving maintenance
6
Full-time student
7
Not working, private means
8
Unemployed – longer than 2 months
9
Sick – only receiving Income Support or Invalidity
Benefit
10
Receiving State Pension only
76

SHOW CARD „16‟
1
Sedatives
2
Sleeping pills
3
Rohypnol®
4
Roofies
5
Row rows
6
Dalmane®, Flurazepam
7
Mogadon®, (Moggies), Nitrazepam
8
Phenobarbitone
9
Tranquillisers
10
Tranks
11
Downers
12
Benzos
13
Roches
14
Librium®
15
Valium®, (Diazepam)
16
Normison®, (Duck eggs), Temazepam
17
Ativan®
18
Halcion®, Triazolam
19
Xanax®
20
Stilnoct®, Zolpidem
21
Zimovane®, Zopiclone
77

SHOW CARD „23‟
1
Oral (Tablets or Syrup)
2
Injection with a needle
3
Other (please tell me)
78

SHOW CARD „24‟
1
I got them on a prescription
2
I got them from someone I know
3
I bought them without a prescription in a
chemist
4
I bought them over the internet
5
79

SHOW CARD „25‟
1
Anti depressants
2
Prozac®
3
Seroxat®
4
Prothiaden®
5
Effexor®
6
Lustral®
7
Molipaxin®
8
Zispin®
9
Olanzapine (Zyprexa®)
80

SHOW CARD „32‟
1
Oral (Tablets or Syrup)
2
3
81

SHOW CARD „33‟
1
2
3
chemist
4
5
82

SHOW CARD „34‟
1
Cannabis
2
Marijuana
3
Dope
4
Grass
5
Pot
6
Hash(ish)
7
Ganja
8
Shit
9
Blow
10
Weed
11
Draw
12
Puff
13
Whacky Backy
14
Skunk
15
Resin
83

SHOW CARD „38‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
84

SHOW CARD „42‟
1
Grass
2
Weed
3
Skunk
4
Hash Oil
5
Herb
6
Hash
7
Resin
8
85

SHOW CARD „44‟
1
Joint
2
Pipe
3
Bong
4
Eat
5
86

SHOW CARD „45‟
1
Ecstasy
2
Pills
3
E
4
XTC
5
Doves
6
Mitsubishi
7
Shamrocks
8
MDMA
9
Yokes
87

SHOW CARD „49‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
88

SHOW CARD „53‟
1
Amphetamines
2
Speed
3
Billy
4
Whizz
5
Base
6
Sulphate
7
Ice
8
Crystal
9
Bennies
10
Uppers
11
Dexies
12
Purple hearts
89

SHOW CARD „57‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
90

SHOW CARD „62‟
1
Crack
2
Rock
3
Stones
4
Freebase
91

SHOW CARD „66‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
92

SHOW CARD „70‟
1
Cocaine
2
Charlie
3
Coke
4
Snow
5
Nose candy
6
Blow
93

SHOW CARD „74‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
94

SHOW CARD „78‟
1
Doing a line/Snort
2
3
Smoke
4
95

SHOW CARD „79‟
1
Heroin
2
Smack
3
Gear
4
H
5
Junk
6
Skag
7
Brown
8
Horse
96

SHOW CARD „83‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
97

SHOW CARD „87‟
1
Smoke
2
3
“Chasing the dragon”
4
98

SHOW CARD „88‟
1
LSD
2
Acid
3
Trips
4
Tabs
99

SHOW CARD „92‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
100

SHOW CARD „96‟
1
Solvents
2
Glues
3
Dry-cleaning fluids
4
Aerosols
5
Paint stripper
6
Petrol
7
Nail varnish remover
8
Correction fluids, e.g. Tipp-Ex®
9
Gas lighter fuel
101

SHOW CARD „100‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
102

SHOW CARD „104‟
1
Poppers
2
Amyl Nitrate
3
Rush
4
Liquid gold
5
Locker room
103

SHOW CARD „108‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
104

SHOW CARD „112‟
1
Magic Mushrooms
2
Psilocybin
3
Mushies
105

SHOW CARD „116‟
1
None
2
Once or twice
3
3 to 5 times
4
6 to 9 times
5
10 to 19 times
6
20 times or more
106

SHOW CARD „120‟
1
I picked them myself
2
3
I bought them off the internet
4
I bought them in a shop/market
5
107

SHOW CARD „121‟
1
Methadone
2
Physeptone®
3
Phy
4
Brown (Phy)
5
Green (Phy)
108

SHOW CARD „128‟
1
I got it on a prescription
2
I got it from someone I know
3
I bought it without a prescription in a
chemist
4
I bought it over the internet
5
109

SHOW CARD „138‟
1
Opiates
(excluding Heroin & Methadone)
2
Temgesic®
3
Codeine
4
Kapake®
5
Morphine
6
Opium
7
DF118® (DF‟s)
8
Diffs
9
Dikes
10
Peach
11
12
Fentanyl
(Durogesic® & Sublimaze® & Actiq®)
Oxycodone
(Oxycontin® & Oxynorm®)
13
MST® (MST‟s)
14
Buprenorphine (Subutex®)
15
Diconal®
16
Pethidine
17
Napps
110

SHOW CARD „145‟
1
2
3
chemist
4
5
111

SHOW CARD „146‟
Anabolic Steroids
1
(This does not include steroids taken for the treatment of
respiratory ailments e.g. Asthma, Arthritis and other
inflammatory conditions)
2
Dianabol
3
Deca-Durabolin®/Durabolin®
4
Nandrolone
5
Stanozolol
6
DHEA
7
Winstrol®
8
British Dragon, Primobol® (Primo)
9
Clenbuterol
10
Methandranone
11
Stanolone
112

SHOW CARD „153‟
1
2
3
chemist
4
5
113

SHOW CARD „153a‟
1
Mephedrone
2
Meph
3
MC
4
MCAT
5
m-cat
6
4-MMC
7
Miaow
8
Meow Meow
9
Bubbles
10
Bounce
11
Charge
12
Drone
13
White Magic
114

SHOW CARD „153h‟
1
I got it from someone I know
2
I bought it over the internet
3
I bought it in a headshop
4
I bought it in a market
5
115

SHOW CARD „153i‟
Party pills or Herbal highs
1
(Doves, Summer Daze, Mint Mania, Rocket Fuel, Dyamite
NRG, Exotix Super, Space E, Groov-e, Xtacy, Myster-e,
Go-e, Blottercaps, Space Trips, Kryptonite, Hibena, Trip-e,
Hypnotic, Flying Dragons, Purple Ohms, Blu-e, Flower
Power, Final-e, Punkys, Bliss Bomb, Beans, Till Dawn, U4e, Dr Feelgood, Space-e Pink Champagnes, Vegas Nights,
Moonwalk, Crazy Jacks, Red Rockets, Green Envy, Road
Runner, Red Roosters, Hummer)
Party Powders
2
(Magic, Dust, Raz, Snow Blow, Snoberry, Blowout, Ivory
Wave)
3
Kratom
4
Salvia Divinorum
(Salvia)
116

SHOW CARD „153r‟
1
I got it/them from someone I know
2
I bought it/them over the internet
3
I bought it/them in a headshop
4
I bought it/them in a market
5
117

SHOW CARD „154‟
1
More as a criminal
2
More as a patient
3
Neither a criminal nor a patient
4
Both a criminal and a patient
118

SHOW CARD „155‟
1
Fully agree
2
Largely agree
3
Neither
4
Largely disagree
5
Fully disagree
119

SHOW CARD „156‟
1
Do not disapprove
2
Disapprove
3
Strongly disapprove
120

SHOW CARD „157‟
1
No risk
2
Slight risk
3
Moderate risk
4
Great risk
121

SHOW CARD „162‟
1
Yes - tried to and stopped
2
Yes - tried to but not stopped
3
No
122

SHOW CARD „163‟
1
Cost/could no longer afford it
2
Persuaded by friends/family
3
Impact on job/friends/family
4
No longer part of social life
5
Concern about health/health reasons
6
Pregnancy
7
Less available supply
8
Put on rehabilitation programme
9
Did not want to take anymore
10
Did not enjoy after effects
11
The pros of taking did not outweigh the
cons
12
123

SHOW CARD „166‟
1
2
3
No
124

SHOW CARD „167‟
1
2
3
4
5
6
Pregnancy
7
8
9
10
11
cons
12
125

SHOW CARD „170‟
1
2
3
No
126

SHOW CARD „171‟
1
2
3
4
5
6
Pregnancy
7
8
9
10
11
cons
12
127

SHOW CARD „171b‟
1
2
3
No
128

SHOW CARD „172‟
1
Given by family/friend
2
Given by a contact I did not know personally
3
Given by a stranger
4
Shared amongst group of friends
5
Bought from a friend
6
Bought from a contact I did not know
personally
7
Bought from a stranger
8
129

SHOW CARD „173‟
1
Street/park
2
Disco/bar/club
3
Office/workplace
4
School/college
5
House of a dealer
6
House of a friend
7
Ordered by phone for
collection/delivery
8
Internet
9
130

SHOW CARD „174‟
1
Very easy
2
Fairly easy
3
Neither easy nor difficult
4
Fairly difficult
5
Very difficult
131

SHOW CARD „175‟
1
2
3
Given by a stranger
4
5
6
Bought from a contact I did not know
personally
7
8
132

SHOW CARD „176‟
1
Street/park
2
Disco/bar/club
3
Office/workplace
4
School/college
5
House of a dealer
6
House of a friend
7
collection/delivery
8
Internet
9
133

SHOW CARD „177‟
1
Very easy
2
Fairly easy
3
4
Fairly difficult
5
Very difficult
134

SHOW CARD „178‟
1
2
3
Given by a stranger
4
5
6
Bought from a contact I did not know personally
7
8
135

SHOW CARD „179‟
1
Street/park
2
Disco/bar/club
3
Office/workplace
4
School/college
5
House of a dealer
6
House of a friend
7
collection/delivery
8
Internet
9
136

SHOW CARD „180‟
1
Very easy
2
Fairly easy
3
4
Fairly difficult
5
Very difficult
137

SHOW CARD „C1‟
1
Less than £520 per year, say less than £10 per week
2
£520 less than £1,040 per year, say £10 less than £20 per week
3
£1,040 less than £1,560 per year, say £20 less than £30 per week
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
£36,400 or more per year, say £700 per week or more
138

SHOW CARD „C2‟
1
£36,400 less than £37,000
31
£130,000 less than £135,000
2
£37,000 less than £38,000
32
£135,000 less than £140,000
3
£38,000 less than £39,000
33
£140,000 less than £145,000
4
£39,000 less than £40,000
34
£145,000 less than £150,000
5
£40,000 less than £41,000
35
£150,000 less than £155,000
6
£41,000 less than £42,000
36
£155,000 less than £160,000
7
£42,000 less than £43,000
37
£160,000 less than £165,000
8
£43,000 less than £44,000
38
£165,000 less than £170,000
9
£44,000 less than £45,000
39
£170,000 less than £175,000
10
£45,000 less than £46,000
40
£175,000 less than £180,000
11
£46,000 less than £47,000
41
£180,000 less than £185,000
12
£47,000 less than £48,000
42
£185,000 less than £190,000
13
£48,000 less than £49,000
43
£190,000 less than £195,000
14
£49,000 less than £50,000
44
£195,000 less than £200,000
15
£50,000 less than £55,000
45
£200,000 less than £210,000
16
£55,000 less than £60,000
46
£210,000 less than £220,000
17
£60,000 less than £65,000
47
£220,000 less than £230,000
18
£65,000 less than £70,000
48
£230,000 less than £240,000
19
£70,000 less than £75,000
49
£240,000 less than £250,000
20
£75,000 less than £80,000
50
£250,000 less than £260,000
21
£80,000 less than £85,000
51
£260,000 less than £270,000
22
£85,000 less than £90,000
52
£270,000 less than £280,000
23
£90,000 less than £95,000
53
£280,000 less than £290,000
24
£95,000 less than £100,000
54
£290,000 less than £300,000
25
£100,000 less than £105,000
55
£300,000 less than £320,000
26
£105,000 less than £110,000
56
£320,000 less than £340,000
27
£110,000 less than £115,000
57
£340,000 less than £360,000
28
£115,000 less than £120,000
58
£360,000 less than £380,000
29
£120,000 less than £125,000
59
£380,000 less than £400,000
30
£125,000 less than £130,000
60
£400,000 or more
139

SHOW CARD „C3‟
1
Child Benefit
2
Retirement Pension or Old Age Pension
3
Pension Credit
4
Income Support
5
Job Seekers Allowance (INCOME BASED)
6
Job Seekers Allowance (CONTRIBUTORY) (was
Unemployment Benefit)
7
Employment & Support Allowance
8
Incapacity Benefit / Youth Incapacity Benefit
9
Attendance Allowance
10
Disability Living Allowance (Care Component)
11
Disability Living Allowance (Mobility Component)
12
Carer‟s Allowance (was Invalid Care Allowance)
13
Widow‟s Pension, War Widow‟s Pension, Bereavement
Benefit (includes Bereavement Allowance and/or
Bereavement Payment) or Widowed Parent‟s (Widowed
Mother‟s Allowance)
14
Maternity Allowance
15
Severe Disablement Allowance
16
Social Fund Loan
17
Industrial Injuries Benefit (i.e. Industrial Death Benefit,
Industrial Injuries Disablement Benefit or Reduces
Earnings Allowance)
18
NONE OF THE ABOVE
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
SHOW CARD „C4‟
1
White
2
Irish Traveller
3
Any other white background (please describe)
4
Mixed – White and Black Caribbean
5
Mixed – White and Black African
6
Mixed – White and Asian
7
Any other mixed background (please describe)
8
Asian - Indian
9
Asian - Pakistani
10
Asian - Bangladeshi
11
Any other Asian background (please describe)
12
Black – Caribbean
13
Black – African
14
Any other Black background (please describe)
15
Chinese
16
Any other (please describe)
141

C. Interviewer Instructions
Drug Prevalence Survey 2010
142

Background
The European Union has an Action Plan on drugs to establish the prevalence
of drug use in the general population of the EU member states.
To enable the EU to take this forward all member countries will be carrying
out population studies using a common methodology and basic questionnaire.
This is the third time this survey has been carried out in Ireland. It previously
ran in 2006/2007 and 2002/2003. It will provide data about the frequency of
drug use (both legal and illegal) among the general population of Ireland.
The Public Health Information and Research Branch of DHSSPS has
commissioned Central Survey Unit to conduct the Drug Prevalence Survey in
Northern Ireland. In the Republic of Ireland, the research has been
commissioned by the National Advisory Committee on Drugs (NACD). These
bodies represent an all-Ireland front in providing data and advice to various
government departments about the prevalence of drug use and other related
aspects.
Survey aims:
Main aim of the survey is to provide up-to-date data about the frequency of drug use among
the general population of Ireland.
It will have many uses, for example, it will:
•
report prevalence and continuation rates of the most common illicit drugs in the
general population by gender and age groups
•
allow cross country assessment of relationships between general patterns of use of
illicit and licit drugs
•
allow the assessment of relationships between particular population attributes and the
use of illicit drugs
Methodology
 5,500 addresses randomly selected from the POINTER address database.
This is a list of all the residential addresses in Northern Ireland. Occupier
names are not given out, as it is the address that is sampled.
 An equal number of addresses have been chosen from each of the 5 Health
and Social Care Trusts in Northern Ireland.
 15 – 64 year olds (inclusive) will be eligible.
 One eligible member of the household will be randomly selected for
interview.
 Written parental consent must be obtained before you can conduct an
interview with a selected individual aged 15 (see page 5 of instructions).
 Households in which all members are 65 or over are ineligible.
 The same study is taking place in the Republic of Ireland.
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
Field Period
 The fieldwork for this survey will run for 4 months from 25th October 2010 to
31st March 2011 (inclusive) with a break of one month for Christmas as
respondents‟ habits could be affected by the festive season.
 Therefore the fieldwork will be divided into two phases:
Phase One: Monday 25th October – Friday 3rd December
Phase Two: Monday 10th January – Thursday 31st March
Allocation
You will get your allocation in monthly batches:
 However, all your phase one allocations will be included in your November
allocation which will be allocated a week early (for period Monday 25th
October – Friday 3rd December).
 Phase two allocations will be allocated monthly.
Phases one and two will be treated as two separate allocations therefore all
phase one allocations must be completed by 3rd December. You cannot
carry over any of phase one allocations to January.
The field period ends on 31st March. There will be no fieldwork extensions.
If you have any reallocations, you must phone your area manager as soon as
possible, so they have time to reallocate them.
Length of the interview
 On average the interview will take approximately 25 minutes.
 For some respondents the interview will be shorter if they have not taken
any drugs, whilst for others who take more types of drugs the questionnaire
may be longer.
Survey Targets
 The target for the survey is 5500 achieved interviews
 There may be a higher rate of ineligibles as some households may not
contain anyone of the required age range.
Advance Letters and Bulletins
Advance letters have been sent to all addresses in the sample for the first
phase of fieldwork. Advance letters for phase two will be allocated in monthly
batches as usual.
144

Use blank copies for households which have not received a letter.
You will be provided with examples of the bulletin that was produced with the
data of the 2006/07 survey. You can show these to respondents who are
interested in what happens to the data. It may also help to show respondents
who are worried about anonymity how the data is collated and used for
statistical purposes only. You will have photocopies of the front page of the
bulletin and can leave one of these with any respondent who would like
further time to think about whether they will participate or with any respondent
who would like one.
Documents
You should have the following documents:
 Cover letter
 Show cards
 Interviewer instructions
 Parental Consent Forms
 A5 return envelopes pre-printed and pre-paid for consents
 Drug use bulletin from the previous survey
 Extra copies of the advance letter
A5 return envelopes should be used to return completed parental consent
forms to the office.
Wages Code
When you are submitting future claims to the Wages Section, please use the
code DP10.
145

Questionnaire
The Questionnaire Format
The questionnaire comprises two sections. These are:(1)
A Household Section
(2)
The Selected Respondent Section
The Household Section
This section involves completing a household grid for the household.
Household Reference Person:
Establish in whose name the accommodation is owned or rented. If there is more than one
person saying yes to this then the Household Reference Person is:
 The person with the highest income
 Where incomes are the same, the eldest person
When filling in the household grid start with the Household Reference Person first, then list all
the other people (adults and children (if applicable)) in the household, in descending order
of age (i.e. youngest last) within the household.
When completing the household grid you will be asked for the name of the
people in the household, this is only used so that you can identify who you
need to interview. It will be removed from all databases to protect
confidentiality. You do not need to enter their name. If you wish you can call
them by an identifier, i.e. husband, wife, daughter etc.
The Selected Respondent Section
The selected respondent is an adult in the household randomly chosen by the questionnaire
program.
Unlike other surveys the selected respondent will be an adult aged 15-64 (inclusive).
Under no circumstances must anyone else in the household be substituted in place of the
selected respondent.
Parental Consent
If your selected individual in the household is aged 15 you need to obtain
written parental permission before you can conduct an interview. Ask the
parent or guardian to read the parental consent form and to sign two copies if
they are happy to give their consent. Then fill in your name, interviewer
number, serial number and date. Let the parent or guardian keep one copy
and send the other copy to the office for the attention of Anne Humphreys in
the pre-paid envelopes provided.
146

It is a parent‟s right not only to know the type of questions that you are going
to ask but to actually sit in on the interview if they wish. Obviously with this
study that would not be ideal so try to explain the subject matter in general
terms (you may already have spoken to the parent as your contact person)
and show the appropriate letter.
If you appear very matter-of-fact about everything, the odds are that the
parent will allow you to conduct the interview alone with the 15 year old. If the
parent wants to sit in you must agree.
Proceed with the interview as instructed and record on the questionnaire the
fact that the parent was present.
If permission is not granted you cannot take an interview and you can code
this on the computer.
Introducing the Study
When you introduce the survey you should explain:
a) Who you are and who the survey is for?
“I work for the Central Survey Unit of the Northern Ireland Statistics and
Research Agency and I am carrying out a survey called „Drug Prevalence
Survey‟ on behalf of the Department of Health, Social Services and Public
Safety (DHSSPS).”
Show your identity card at all addresses and to anyone who asks to see it.
b) What the survey is about?
Start by explaining the purpose of the survey: Say something like “The main
aim of this survey is to provide the government with an up-to-date picture of
the prevalence of drug use in Northern Ireland. The study is therefore all
about people‟s consumption of medicines and drugs, tobacco and alcohol.
c) How long will the survey take?
The questionnaire will take 25 minutes on average. However, for some
respondents the interview will be shorter if they have not taken any drugs,
whilst for others who take more types of drugs the questionnaire may be
longer.
d) Will anybody be able to identify my replies?
“No, nobody will know who said what. The information that you give to the
interviewer will be kept in strict confidence. The results will not be used in any
way in which they can be associated with you or your address. Similarly no
147

identifiable information about you or your household will be passed on to any
other government department, or anyone else. The data collected in this
survey is used for statistical purposes only.”
e) How can I be sure you are a genuine interviewer?
“I have shown you my identity card but if you are in any doubt as to whether I
am a genuine caller, you can contact QUICK CHECK (a local PSNI initiative),
on FREEPHONE 0800 013 22 90. I also have a copy of the advanced letter
you were sent explaining the survey.” If the respondent still has concerns they
can telephone Liz Graham (see back page for contact details).
f) But I don‟t take drugs / know anything about drugs. My participation is
pointless.
“It is important that we do not overestimate the prevalence of drug use in
Northern Ireland. The more people who participate the more accurate the
picture of drug use in Northern Ireland will be. It is just as important that
people who do not take drugs take part as those who do. The survey does
not just collect information on drugs but on alcohol and tobacco use as well.”
Interview Setting
Make every attempt to interview in a one-to-one setting. This is desirable for
most surveys: in this study it is essential.
The purpose of the interview is to determine the respondent‟s use of tobacco,
alcohol and drugs sometimes used as medicines and illegal drugs. While the
use of illegal drugs these days is not necessarily seen as something to be
embarrassed about or kept quiet by those who use them, nevertheless, many
people would not freely talk about their use of these types of drugs in front of
members of their family.
If invited into a living room with other members of the household present,
decline and say something like – “I don‟t want to disturb them, can we do the
interview in the hall or the kitchen or somewhere we can be private?”
As these are personal questions, the respondent will be asked to just call out a number from
the show card during the interview. Thus offering the respondent a certain level of privacy if
anyone else is in ear shot.
Reassure respondents at the beginning of the interview about confidentiality.
Their names and individual address will not be linked to their answers.
Indeed the only reason for taking their names is to check that you, the
interviewer, have carried out your work accurately. Explain as you usually do
about backchecking and give whatever reassurance is needed as to their
complete anonymity.
148

Point out if you need to that the answers of all the people interviewed on this
study (5,500 in Northern Ireland) are input to a computer using codes and
then the results are produced as statistics, tables of figures etc.
You must ask all the questions as they are written, in the order that they
appear and you must not (as in all surveys) reveal any emotion or reaction to
any of the answers given to your questions.
You must appear interested in what your respondent says in order to
encourage him/her to keep answering but please do not engage in discussion
or pass any opinion about the topic of the study or answers you have been
given.
If it helps secure an interview or in response to the enquiry “What‟s it for?” you
may tell your respondent (or contact) that although everyone has an opinion
about the prevalence of drug use in Northern Ireland, no one actually knows
how widespread it is in 2010/11 or indeed any other real information.
The information gathered from this study will be used by various government
departments to plan resources needed for education, rehabilitation etc.
Drug Prevalence Questions
Content
The survey will ask about a range of substances:
• Tobacco products
• Alcohol
• Sedatives or tranquillisers
• Anti-depressants
• Cannabis
• Ecstasy
• Amphetamines
• Crack
• Cocaine
• Heroin
• LSD
• Solvents
• Poppers
• Magic mushrooms
• Methadone
• Opiates
• Anabolic steroids
• Mephedrone
• Legal highs
The show cards will give a list of all the different names for each of the drugs.
149

This section of the questionnaire comprises of 3 main modules:
1. Standard questions on tobacco, alcohol, medicines and illegal drugs. The
questions in this module are repeated for each substance and are in the
following format:
• Have you ever heard of any of these?
• Do you personally know people who take X?
• Have you ever taken X?
• At what age did you first take X?
• How many times have you been offered X either free of charge or to
buy in the last 12 months?
• During the last 12 months have you taken X?
• During the last 30 days have you taken X?
• During the last 30 days, on how many days have you taken X?
• What method do you most commonly use to take X?
• On the last occasion you took X how had you obtained it?
2. Opinion questions:
• How they perceive drug addicts
• Whether they disapprove of certain behaviours related to drugs,
tobacco & alcohol
• What behaviours they consider harmful
3. Additional questions. The questions in this module are repeated for some
of the substances the respondent said they had used in the standard
questions and are in the following format:
• Have you taken X regularly?
• At what age did you first take X regularly?
• Have you ever tried to stop taking X?
• What was the main reason for stopping taking X?
• How did you get X on the last occasion you used it?
• In which of the following places did you obtain X on the last occasion
you used it?
• How easy or difficult is it to obtain X in a 24 hour period?
General points
The drug prevalence questions are straightforward and clearly set out.
Use the show cards where instructed. The number on the show card should
correspond to the question number in the blue section of CAPI.
Each section is laid out in similar fashion, as is the type of question. The
exact words must be used. Do not abbreviate questions or leave any out. Do
not assume that you know the answer to a particular question because of a
previous answer.
Where exact ages or number of days is required to be recorded and a
respondent may not be sure, get them to give you their best estimate.
150

For example, if you are talking to a smoker in his mid forties and he cannot
remember whether he was 14 or 15 when he first smoked tobacco products
ask him just to give you the one he thinks. He needs to make the judgment
not you or the editor who checks the data. So use one figure.
Please try to get a figure. Don‟t knows are not very useful to anyone.
If your respondent says “no, that they have never …..” (whatever the section
is asking about) they will be routed to the next section.
At other places in the questionnaire routing applies. Please become familiar
with the routing before going out to interview.
Specific Points to note
(Question numbers are in the blue section of the CAPI screen)
Q.3 asks “At what age did you smoke tobacco products for the first time?”
If you enter an age 8 years old or younger an interviewer message will flash
onto the screen.
INTERVIEWER: CAN YOU CHECK YOU HAVE TYPED THE CORRECT
AGE AS <whatever age you typed> SEEMS VERY YOUNG
This is asking you to check you have entered the correct age. This error
message is there solely to ensure you have entered the data correctly.
Please do not say „this is very young to be having your first smoke. Are you
sure?‟ Just check you have not mistyped. If you have mistyped touch „close‟
and enter the correct age. If you have not mistyped and the respondent did
state they smoked before the age of 8 click „suppress‟ and you will be moved
onto the next question.
PLEASE ENSURE YOU ALWAYS READ THESE ERROR MESSAGES
THAT FLASH ONTO THE SCREEN AS SOME WILL BE POINTING OUT
INCONSISTENCIES IN THE DATA. FOR INSTANCE YOU MAY HAVE
CODED THE RESPONDENT AS FIRST SMOKING AT AN OLDER AGE
THAN THEY PRESENTLY ARE. E.G. CODING A 15 YEAR OLD AS
HAVING THEIR FIRST SMOKE WHEN THEY WERE 20.
Q.11 asks “At what age did you first drink alcohol?”
This refers to the occasion on which the respondent had their first „real‟ drink
and not just a taste or sip.
At Q.16 you introduce the show cards. Only allow the respondent to look at
the card relevant to the question. The card numbers match the question
numbers.
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Ask the question “Have you ever heard of any of these?” showing the relevant
card at the same time. If the respondent says „yes‟ they will be asked other
questions about the drug. If they say „no‟ they will be routed to the next
section.
Use the appropriate show cards and where applicable ask the respondent just
to call you out the number(s) that applies to their answer(s).
At Q.17
“SHOW CARD 16
All of the drugs listed on this card are names for sedatives or tranquilisers.
Do you personally know people who take sedatives or tranquillisers?”
„Personally‟ is to be defined as someone the respondent knows (family
member, friend etc.) rather than someone they know of (i.e. a friend of a
friend).
Continue for all substances.
Note the wording of Q.156a-e
“Individuals differ in whether or not they disapprove of people doing certain
things. I will mention a few things, which some people might do. Can you tell
me if you would not disapprove, disapprove or strongly disapprove when
people do any of these things...”
Not disapproving is not the same as approving and it may be helpful to
emphasize the not disapprove slightly when reading the question.
At Q.157b
“(Now I would like to know how much do you think that people risk harming
mention a few things some people might do. Please tell me if you consider it
to be no risk, a slight risk or a great risk, if people do such things):
Have five or more drinks at the weekend?”
„Five or more drinks at the weekend‟ means having five or more drinks on any
one of the days Friday, Saturday or Sunday. It does not mean 5 drinks in total
across all three days.
This question can also illustrate what to do with text enclosed within brackets.
The preamble to Q157b is bracketed as it was already read out for Q157a and
does need not be read again. It only appears on the screen in case you feel
you need to read it again. For instance, the interview may have been
interrupted and you need to remind the respondent of the full question.
152

Questions Q.157c, Q.158-161, Q.164, Q.165, Q.168, Q.169 and Q.171a ask
the respondent whether they have taken certain things “regularly”, i.e. drunk
alcohol, taken cannabis, ecstasy, cocaine and mephedrone. In this instance
“regularly” should be self defined by the respondent. If asked what you mean
by or how often is “regularly”, say to the respondent that it means whatever
he/she considers “regularly” to mean or however often he/she considers
something to be regular.
153

General Field Procedures
Completing Fieldwork
The following information is taken from the interviewer circular New Fieldwork
Procedures which was issued on 3rd March 2008. It relates to calendar month
allocations.
 You should start working on your allocation of work in the first couple of
days of fieldwork and progress through it on a weekly basis. You should
aim to have 85% of your allocation of work completed before the final week
of fieldwork;
 You are expected to schedule your calls to productive times when people in
your area are most likely to be in. Calls should be spread over the entire
fieldwork period;
 You are expected to carry out your work efficiently by planning your route
etc and be dedicating reasonable blocks of time when you carry out your
interviewing duties;
 You are expected to update the outcome code or status of each address on
an ongoing basis to make sure that the outcome status and calls details at
each address are fully up to date prior to the weekly „dial up‟;
 All fieldwork must be completed by the end of the monthly fieldwork
schedule.
Return of Work
You must dial up on a weekly basis.
Please update the „current interview status‟ for each interview before
transmission to the office.
We will check the progress of the survey every Monday during the field period
so it important that you dial up weekly.
Dial up times are in the weekly news.
If your backup fails, please contact the office on the following Monday and we
will enable you to make another attempt.
If you know you will be unavailable over the weekend, please contact the
office beforehand and we will enable a backup during the week.
154

Weekly News
Please read the Weekly News carefully after your dial up each week. It will
contain important information which is often critical to the smooth running of
the survey. This could include a request to undertake specific action during
the following week.
Use of translators
If you need a translator contact Anne Humphreys on 028 9034 8255 and she
will be try to arrange for a translator. You will obviously need to know the
language spoken. It could take at least 5 days for this to be arranged.
General Rules
(a) Visit every address on the list. Addresses should not necessarily be
interviewed in numerical order but grouped for economy.
(b) If you are unable to find the address listed do not substitute another
address but refer to the office immediately.
(c) Always show your Authority Card on the doorstep and give the respondent
time to view it properly.
(d) Always stress that all information is confidential.
(e) Give an explanation of the Survey and how the address came to be
selected.
(f) Do not interview on the doorstep.
(g) Record all answers at the time of conducting the interview.
(h) Calls, in line with field force section guidelines, at varying times of the
day, must be made before an address can be classified as a non-contact.
Your calls at each address should be spread across the field period and
you should make morning, afternoon and evening calls to each address.
(i) Notify Headquarters immediately if there is a delay in the fieldwork. Phone
your Area Manager.
(j) Study time of 2 hours will be paid for this survey. You will be expected to
go through a questionnaire in detail in this time and to read the
instructions.
155

Eligibility of Addresses
We are interested only in private households; thus any address which is not a
private residence, whether in whole or in part, should be disregarded:BUT NOTE
(1) A house or flat with a shop is a private residence.
(2) If the address is a school or business premises (eg offices) there may be
a resident caretaker; if so, interview the caretaker‟s household.
(3) Interview the owner/proprietor of a guesthouse/private hotel if the
owner/proprietor runs it and lives on the premises.
YOU SHOULD EXCLUDE
(1) hostels.
(2) institutions, e.g. schools, hospitals (but see (2) above).
(3) business premises (but see (2) above).
(4) hotels (but see (3) above).
(5) demolished houses.
(6) derelict and empty houses.
Household Definition
(a) Once you have established an eligible address and made contact it is
important to establish the household who live at that address.
A household is defined as a single person or group of people who have the
address as their MAIN or only address and who either:(1) Share one meal a day. (This does not necessarily imply that they must
always sit down to eat together, but can be that the food is bought or
provided on a common basis.)
OR
(2) Shared living accommodation:
(i) accommodation may still be regarded as shared where the address
does not have an actual living room which is separate from the
kitchen (ie where the main living room forms part of the same room as
the kitchen);
(ii) a household can be treated as one if the living room is also used as a
bedroom;
156

(iii) never regard as one household solely on the basis of a shared
kitchen and/or bathroom.
(b) Multi-households are best defined as a group of people who reside
at a dwelling but do not share living accommodation or food/eating
arrangements.
157

Office Contacts for Queries
Questionnaire Issues
Liz Graham – 02890 348219
Admin Queries
Anne Humphreys – 02890 348255
Allocation Queries
Please contact your Area Manager
158

D. Advance letter to Households

159

E. Parental Permission Form
160

161

F. Design Effects & CIs
Prevalence rates, design effects and
confidence intervals, prepared by Julia
Sevtsenko, under supervision of Dr Peter
Mühlau
2011
162

Introduction
The current report was submitted to PHIRB within DHSSP and includes the
methodology on statistical tests performed for the analysis of data of the All Ireland
Drug Prevalence Survey 2010/11. In this study, prevalence rates, design effects and
confidence intervals were calculated for each drug type broken-down by the following
main categories: all respondents; gender (males and females); age groups (15-24
years, 25-34 years, 35-44 years, 45-54 years, 55-64 years; young adults 15-34 years
and older adults 35-64 years); and gender by age groups (each gender group was
divided into the different age groups). All results were produced at both Northern
Ireland and at Health and Social Care Trust (HSCT) levels. Statistical comparisons of
prevalence rates were performed between three surveys: the 2002/03 survey, the
2006/07 survey and the 2010/11 survey. As a result of changes in survey design and
measurement, statistical comparisons were not performed for the following
categories:
-
the gender by age group. This category did not exist during the 2002/03 and
2006/07 surveys;
-
Belfast and South-Eastern HSCTs. In 2009, five HSCTs (Belfast HSCT=1;
Northern HSCT=2; South Eastern HSCT=3; Southern HSCT=4; Western
HSCT=5) replaced the previous four Health Boards presented in 2002/03 and
2006/07 surveys (Eastern HSSB=1; Northern HSSB=2; Southern HSSB=3;
Western HSSB=4). Hence, the statistical comparison was available for three
Health Boards (Northern, Southern and Western) that were not affected by the
reconstruction;
-
mephedrone and legal highs. These types of drugs were first introduced in the
2010/11 survey;
-
sedatives & tranquilisers and anti-depressants. These types of drugs were first
introduced in the 2006/07 survey; hence the comparison was relevant between
the 2006/07 and 2010/11 surveys only.
Some drug types that were included in the 2006/07 survey were then omitted from the
2010/11 survey, making it difficult to perform statistical comparisons. To effectively
compare the results of all the surveys, two additional drug types, included in the
2006/07 survey, were computed and added to the 2010/11 survey: Opiates (total)
(including Heroin, Methadone and Other Opiates) and STA (including Sedatives and
Tranquilisers, and Anti-depressants).
163

Prevalence
It is evident that the use of drugs in a population alters over time. Drug Prevalence
surveys aim to discover the proportion of the population consuming particular drugs
at different points of time. Lifetime prevalence, 12-month prevalence and 30-days
prevalence were implemented as the ‘points of time’.
At Northern Ireland and at HSCT levels, point prevalence was computed for each
drug type in all subgroups:
Pl 
kl
 100% ,
n
where k represents those who are definite drug users in the sample;
n signifies the sample size derived from the Drug Prevalence survey;
l denotes the prevalence measure.
It is important to note that prevalence rates computed within the survey only provide
an estimate of the population prevalence rate, or the point estimate.
Weighting
The sample size derived from the Drug Prevalence survey represents an estimate of
the population from which the sample was drawn. In order to correct disproportions in
the sample size and to adjust the collected data, weighting was introduced.
Northern Ireland and the HSCTs have normalised weights based on gender and age
group and these are calculated by dividing frequency weights by the average
frequency weights within the HSCT, where frequency weights are determined by the
following fraction:
whga 
PE
N hga
S
nhga
,
where N PE is the population size according to the 2009 Mid Year Population Estimate
(published by NISRA);
n S represents the sample size derived from the All Ireland Drug Prevalence survey;
and
h (= 1 to 5) means the Health and Social Care Trust (HSCT),
g (= 1 to 2) denotes gender,
a (= 1 to 5) is the age group.
Cases with missing values for the weighting variable were automatically excluded
from the analysis by the programme.
Some statistical calculations, for instance where weighted samples are less accurate,
do not require preliminary weighting, so weighting was not applied.
The results obtained from the calculation of normalised weights for Northern Ireland
and each of the HSCTs based on gender and age group proved to be identical to the
results provided by PHIRB.
Design effect
The design effect determines the impact of design on sampling variability. For the
Drug Prevalence survey, design effect was calculated by complex samples algorithm
164

in SPSS 16.0. According to Kish (1965), the design effect is the ratio of the variance
under the complex sample design to the variance under the simple random sample
design:
Deff 
V ( Nˆ )
,
V ( Nˆ )
srs
where Vˆ ( Nˆ ) stands for the variance under the complex sample design;
and Vˆsrs ( Nˆ ) signifies the variance under the simple random sample design.
n
In SPSS 16.0, design effects are computed only when the condition
1 is satisfied.
Nˆ
The variances of parameter estimates are computed in SPSS using the Taylor series
expansion method, which involves the estimation of non-linear equations. This
method is extensively used and considered to be the ‘gold standard’ of variance
estimation. A complex sample design employed for the design effect calculations
consists of two following components: Stratification and Weighting, with Health and
Social Care Trusts used as Strata.
While calculating the design effects for each drug type for the different HSCTs,
broken-down into gender and age (5 categories) group, the results revealed no
stratification, clustering or differential weighting. The design effects for this group
were set to 1.000 and an effective sample size and confidence intervals were
calculated.
Effective sample size
The effective sample size refers to the sample size that is obtained using simple
random sampling and it is equivalent to the sample size under the complex sampling
methods. The effective sample size is calculated using the following equation:
neff 
n
,
deff
where n signifies the actual sample size;
and deff indicates the design effect.
Design effect: Descriptives
Table 1 describes the summary of the design effects for the All Ireland Drug
Prevalence Surveys for 2002/03, 2006/07 and 2010/11. The table presents the mean
design effect and its standard deviation for all of the estimated design effects (column
DEFF). Column DEFF(LIM) refers to the design effects that have been used for the
calculation of the confidence intervals and these are larger than 1 (any design effect
that was less than 1 had to be set to 1).
Notably, design effects for the 2010/11 survey are smaller than for the 2002/03 and
2006/07 surveys. Last year prevalence design effects were slightly larger than both
lifetime and last month prevalence. In general, design effects are larger both for males
than for females and for young adults (particularly 15-24 years) than for older adults.
Younger females and, especially, males produce larger design effects than older males
165

and females. In addition, design effects for ecstasy, legal highs, mephedrone and
amphetamines are the largest, whereas heroin, solvents and crack are the smallest of
the drug types used in the study.
Table 1
Total
Prevalence
Lifetime
Last Year
Last Month
Subsample
All
Males
Females
15-34
35-64
15-24
25-34
35-44
45-54
55-64
Males 15-34
Males 35-64
Females 15-34
Females 35-64
Males 15-24
Males 25-34
Males 35-44
Males 45-54
Males 55-64
Females 15-24
Females 25-34
Females 35-44
Females 45-54
Females 55-64
2002/03
DEFF
DEFF(LIM)
Mean SD Mean SD
1.26 0.25 1.27 0.22
2006/07
DEFF
DEFF(LIM)
Mean SD Mean SD
1.32 0.35 1.34 0.31
2010/11
DEFF
DEFF(LIM)
Mean SD Mean
SD
1.13 0.29 1.16
0.26
1.28
1.24
1.24
0.26
0.23
0.25
1.29
1.26
1.26
0.23
0.21
0.22
1.38
1.30
1.26
0.34
0.34
0.35
1.39
1.33
1.29
0.32
0.31
0.31
1.14
1.15
1.11
0.29
0.29
0.29
1.17
1.18
1.13
0.26
0.26
0.26
1.40
1.39
1.20
1.42
1.06
1.50
1.23
0.96
1.22
0.92
0.20
0.20
0.17
0.18
0.14
0.15
0.15
0.10
0.18
0.15
1.40
1.39
1.20
1.42
1.09
1.50
1.23
1.02
1.23
1.01
0.20
0.20
0.16
0.18
0.12
0.15
0.14
0.04
0.18
0.02
1.49
1.63
1.03
1.50
1.20
1.57
1.35
1.06
1.20
0.99
0.40
0.32
0.19
0.31
0.23
0.26
0.24
0.19
0.22
0.17
1.51
1.63
1.09
1.50
1.23
1.57
1.36
1.11
1.21
1.05
0.38
0.32
0.12
0.30
0.18
0.25
0.21
0.13
0.20
0.07
1.21
1.24
1.14
1.39
0.98
1.67
1.02
0.98
0.99
0.93
1.45
1.01
1.26
0.90
1.74
1.05
1.05
0.96
0.98
1.48
0.98
0.88
1.01
0.88
0.18
0.18
0.23
0.18
0.06
0.28
0.05
0.08
0.05
0.13
0.24
0.05
0.20
0.10
0.36
0.05
0.04
0.03
0.11
0.25
0.08
0.10
0.13
0.15
1.21
1.24
1.16
1.39
1.01
1.67
1.03
1.02
1.02
1.01
1.45
1.02
1.27
1.00
1.74
1.05
1.05
1.00
1.02
1.48
1.01
1.00
1.05
1.00
0.17
0.18
0.20
0.18
0.03
0.28
0.04
0.04
0.03
0.05
0.24
0.03
0.18
0.01
0.36
0.05
0.04
0.01
0.05
0.25
0.04
0.00
0.09
0.00
166

Drug Type
Alcohol
Tobacco
Cannabis
Opiates (total)
Heroin
Methadone
Other opiates
Cocaine (including
crack)
Crack
Cocaine powder
Amphetamines
Ecstasy
Mephedrone
LSD
Magic Mushrooms
STA
Solvents
Poppers
Anabolic steroids
Legal highs
Any illegal drugs
Sedatives &
Tranquilisers
Anti-depressants
1.11
1.25
1.40
1.27
1.32
1.18
1.20
0.19
0.22
0.30
0.28
0.18
0.17
0.34
1.14
1.25
1.41
1.29
1.32
1.18
1.25
0.15
0.21
0.28
0.25
0.17
0.17
0.25
1.26
1.39
1.64
1.41
1.01
1.04
1.45
0.29
0.23
0.46
0.34
0.26
0.23
0.36
1.27
1.39
1.64
1.42
1.11
1.11
1.46
0.27
0.23
0.46
0.33
0.16
0.18
0.35
1.12
1.12
1.10
1.14
0.98
1.16
1.14
0.28
0.28
0.33
0.29
0.07
0.28
0.29
1.16
1.16
1.17
1.18
1.00
1.17
1.17
0.24
0.24
0.26
0.26
0.02
0.27
0.26
1.34
0.21
1.35
0.21
1.40
0.23
1.40
0.23
1.16
0.37
1.21
0.33
1.22
1.35
1.29
1.32
0.21
0.20
0.19
0.17
1.23
1.35
1.29
1.32
0.20
0.20
0.19
0.17
1.22
1.41
1.26
1.48
0.24
0.24
0.26
0.34
1.25
1.41
1.30
1.48
0.19
0.24
0.20
0.34
1.23
1.22
1.12
1.22
1.25
0.15
0.26
0.13
0.22
0.23
1.23
1.25
1.14
1.23
1.26
0.15
0.25
0.10
0.20
0.22
1.27
1.40
1.18
1.09
1.35
1.21
0.34
0.28
0.19
0.32
0.29
0.39
1.31
1.40
1.18
1.19
1.37
1.29
0.29
0.28
0.15
0.21
0.25
0.28
1.41
0.32
1.42
0.30
1.66
0.48
1.66
0.46
1.08
1.17
1.19
1.21
1.20
1.11
1.12
1.11
1.07
1.16
1.15
1.20
1.11
0.26
0.36
0.32
0.35
0.28
0.27
0.25
0.29
0.16
0.25
0.29
0.29
0.33
1.12
1.21
1.20
1.23
1.20
1.13
1.13
1.15
1.08
1.17
1.18
1.21
1.18
0.23
0.33
0.31
0.33
0.27
0.26
0.24
0.25
0.15
0.24
0.27
0.28
0.26
1.14
0.17
1.16
0.15
1.12
0.29
1.16
0.26
1.11
0.13
1.12
0.12
1.12
0.29
1.16
0.26
167

Design effect-adjusted confidence intervals
Design effect-adjusted Clopper-Pearson for determining single proportions
Confidence intervals are important because they provide a range of the true
population value that helps to determine the accuracy of the prevalence estimate. The
width of confidence intervals depends on the standard error, which, in turn, depends
on n. The standard confidence level for drug prevalence studies is 95%, meaning that
95 percent of confidence intervals are expected to include the population prevalence
rates.
In order to estimate confidence intervals for the 2010/11 Drug Prevalence survey, the
Clopper-Pearson method was applied. This method is considered to be the classic
method and provides minimum coverage probabilities of 0.975 with a non-coverage
value of 0.025. As SPSS does not provide an appropriate command for the
computation of Clopper-Pearson confidence intervals, such a command was designed
separately and performed in SPSS.
To calculate Clopper-Pearson design effect-adjusted confidence intervals, the proper
estimation method for complex survey data should be performed:
pˆ (1  pˆ )
n

var( pˆ )
deff
k '  pn' ,
n' 
where n’ is an effective sample size;
p̂ represents the estimate of the proportion;
var( p̂ ) refers to the sampling variance of the proportion;
n indicates the actual sample size;
deff signifies the design effect;
and k’ is the effective sample size of all definite drug users.
The Clopper-Pearson method is adjusted for complex designs (design-effect
adjustment) by substituting n for n’ and k for k’:
 (a / 2; k '; n'k '1);  (1  a / 2; k '1; n'k ' ) for 0<k<n;
0;  (1  a / 2; k '1; n'k ' ) for k=0;
 (a / 2; k '; n'k '1);1 for k=n.
1
1
1
1
Design effect-adjusted Newcombe’s hybrid for calculating the difference between
two proportions
There are more than a dozen methods for establishing confidence intervals that
calculate the difference between independent proportions. Newcombe developed a
hybrid efficient score method based on the Wilson score method. Importantly, this
hybrid method overcame problems of inefficient coverage and it was not as complex
as some of the other methods.
The following equations outline the design effect-adjusted Wilson score intervals for
single proportions:
168


1 2
1 2
z1 a / 2  z1 a / 2 var( pˆ ) 
z1 a / 2
 pˆ i 
2n' i
4n' i

Upper limit:

1 2
1
z1 a / 2

n
'
i








1 2
1 2
z1 a / 2  z1 a / 2 var( pˆ ) 
z1 a / 2
 pˆ i 
2n' i
4n' i

Lower limit:

1 2
1
z1 a / 2

n
'
i







While the following represents the derivation of Newcombe’s hybrid score confidence
limits determining the difference between two proportions as developed from the
lower and upper limits of the design effect-adjusted Wilson score intervals for single
proportions:

UL p1 (1  UL p1 ) LL p2 (1  LL p2 ) 

Upper limit: ( pˆ 1  pˆ 2 )  z a / 2

n'1
n' 2



LL p1 (1  LL p1 ) UL p2 (1  UL p2 ) 

Lower limit: ( pˆ 1  pˆ 2 )  z a / 2

n'1
n' 2


Similar to the Clopper-Pearson method, SPSS does not provide a command for the
computation of Newcombe’s hybrid score confidence intervals, thus it was necessary
to design and perform an appropriate command in SPSS.
169

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