The Scottish Crime and Justice Survey ( SCJS) is a large-scale continuous survey measuring people's experience and perceptions of crime in Scotland. The survey is based on, annually, 16,000 in-home face-to-face interviews with adults (aged 16 or over) living in private households in Scotland.
The main aims of the SCJS are to:
- Provide a valid and reliable measure of adults' experience of crime, including services provided to victims of crime;
- Examine trends in the number and nature of crime in Scotland over time;
- Examine the varying risk of crime for different groups of adults in the population;
- Collect information about adults' experiences of, and attitudes to, a range of crime and justice related issues.
The main findings for 2009/10 are presented in a series of four reports. This report presents the key findings about illicit drug use collected through the self-completion section of the survey. A Technical Report and User Guide are also available. 2
The SCJS is the only source of information on self-reported drug use among the adult population of Scotland as a whole (Box 1.1). Information on experience of illicit drug use was collected through the self-completion section of the questionnaire, which was completed by 13,418 (84%) of the 16,036 respondents to the main SCJS questionnaire.
The data for the survey are available on the UK Data Archive in SPSS format. 3 The analysis in this report is not exhaustive, and readers are encouraged to conduct their own analysis of the primary data. Supporting documentation for the survey, as well as generic teaching datasets, is also provided on the UK Data Archive.
The main aim of the self-completion illicit drug use questions was to establish whether adults aged 16 or over reported using any of 16 specified drugs either at some point in their lives, in the last year and in the last month. Those who had used any types of drugs were asked a series of follow-up questions to provide more detail about being offered drugs, first drug use, and the drug used most often in the last month. Further details of the questionnaire content can be found in Annex 2, section A2.2.
Box 1.1: SCJS data on self-reported illicit drug use
The SCJS is the only source of information on self-reported illicit drug use in the general adult population at national level in Scotland. 4 A range of stakeholders in the drugs field, including the Scottish Government's Drugs Policy Unit, 5 Scottish Crime and Drug Enforcement Agency ( SCDEA) 6 and service providers, benefit from up-to-date information on illicit drug use and trend data among adults aged 16 or over in Scotland.
The Scottish Government's Drugs Strategy, 7The Road to Recovery (2008), 8 recognises that effective treatment must be tailored to the needs of individuals in recovery from drug use and highlights the importance of relevant and credible substance misuse education to prevent substance misuse, informed by a strong evidence base. A review of the evidence base underpinning drugs recovery was published by the Scottish Government in September 2010 (Best, e t al, 2010). However, continued, up-to-date and accurate information about substance use in Scotland is vital in allowing government and other stakeholders to respond promptly and appropriately, and in informing the successful delivery of the drugs strategy.
This report provides information which is of use to policy makers, practitioners, NHS and voluntary service providers to help build a picture of drug use in the general adult population and provide evidence on the latest trends in drug use for prevention / education work and service-planning purposes.
The SCJS was sampled from private residential addresses in Scotland using the Royal Mail Postcode Address File ( PAF). One adult aged 16 years or over per household was then randomly selected for interview. As the survey only included private residential addresses, it is acknowledged that it under-represented key groups who were likely to use illicit drugs (section 1.3).
Questions on illicit drug use were included in the self-completion section of the questionnaire, which was undertaken at the end of the main SCJS interview. Respondents were handed the interviewer's tablet computer and guided by the interviewer through a series of practice questions which explained how to use the computer. Where respondents were unable or unwilling to use the tablet computer themselves, interviewers administered the interview, showing the respondent the screen and helping them to input their answers.
Participation was voluntary, with 13,418 (84%) of the 16,036 respondents to the main survey completing the self-completion questionnaire. Non-response was higher among older people (see Annex 2, section A2.5 for further details).
A more detailed explanation of the methodology for the survey can be found in Annex 2, and the accompanying Technical Report. 9
1.3 Limitations of the data
Self-reporting drug surveys are valuable in providing information on illicit drug use when there are few other sources of available data about the population as a whole. However, it is recognised that such surveys do have limitations.
First, it is likely that there will be an under-representation of some groups who take drugs. In part, this will be due to the fact that some groups of drug users live in accommodation not covered by a survey of private households (such as the SCJS) including, for example, hostels, prisons and student halls of residence. The survey is likely to under-represent the most problematic or chaotic drug users, some of whom may live in accommodation previously described and some of whom may live in private households covered by the survey, yet who may rarely be at home or able to take part in an interview due to the nature of their lives.
Secondly, despite using Computer Assisted Self-completion Interviewing ( CASI) for this module, it is likely there will be a certain amount of under-reporting of illicit drug use among survey respondents. Illicit drug use is an illegal activity and as such some individuals may have felt uncomfortable reporting that they have taken illicit drugs, despite reassurances about confidentiality and anonymity.
Thirdly, questions cover past use over varying periods ( ever, in the last year and in the last month) and it is possible that some respondents may simply forget occasional uses of a certain drug, particularly if they last took it a long time ago.
While under-reporting of drug use on surveys such as the SCJS is almost certain, it should be noted that the issues discussed above are unlikely to apply equally across all types of drugs. While a survey such as the SCJS is likely to provide an insight into the more commonly used drugs, in particular cannabis, it may be less effective in providing information for some of the Class A drugs such as opiates or crack cocaine, where a sizeable number of users may be concentrated in small sub-groups of the population not covered by the survey (Hoare, 2009).
In addition, while under-reporting is by far the main limitation of this type of household survey, it is also recognised that some people may report taking drugs when they have not actually done so for a number of reasons. To try and counter this mis-reporting, a non-existent drug (semeron) was included in the list of drugs presented to respondents. Including the name of a fictitious drug is a technique that is commonly used in drug surveys (see for example Hoare, 2009; Brown and Bolling, 2007; Black et al., 2009). In the SCJS 2009/10, nine respondents reported that they had ever taken semeron and were, therefore, excluded from the analysis presented in this report.
1.4 Classification of drugs
The Misuse of Drugs Act 1971 classifies illegal drugs into three categories (Class A, B and C) according to the harm they cause. The 16 drugs that respondents were asked about and their classification under the Act are: 10
- Class A, including cocaine, crack, crystal meth, ecstasy, LSD, magic mushrooms, heroin, methadone and amphetamines (if prepared for injection); 11
- Class B, including amphetamines (in powdered form) and cannabis;
- Class C, including ketamine, temazepam, valium and anabolic steroids;
- Not classified, including poppers and glues, solvents, gas or aerosols.
In addition to reporting by Class, a number of other composite drug groups are reported. These composite groups, and the individual drugs that they include, are:
- Opiates, including heroin and methadone;
- Stimulant drugs, including cocaine, crack, crystal meth, ecstasy, amphetamines and poppers;
- Psychedelics, including LSD, magic mushrooms and ketamine;
- Downers / tranquilisers, including temazepam and valium.
The groups include illicit drugs across the legal classification and reflect the drugs' shared properties, effects and characteristics, providing an additional measure to the class-based categorisation. For example, stimulant drugs may be used interchangeably by the same people at similar times and in similar settings.
Drugs not included in the composite groups such as cannabis, anabolic steroids and glues, solvents, gas or aerosols, are included separately in appropriate figures where sufficient data are available to do this.
Box 1.2: Legal highs
Reflecting the proliferation of so-called 'legal highs' / former 'legal highs' the 2010/11 SCJS drugs section of the self-completion questionnaire was amended to include five additional drugs:
- Mephedrone (mmcat, 4-mmc, 'meow', 'doves', 'bubbles');
- BZP (benzylpiperazine);
- GBL (gamma-butyrolactone, liquid 'e') or GHB (gamma-hydroxybutyrate);
- Synthetic cannabinoids (such as 'spice', 'space');
- Khat (quat, qat, qaadka, chat, jaad).
Data from the 2010/11 SCJS will be reported early in 2012.
1.5 A note on reference periods
In the survey, respondents were asked about their history of drug use over three different time periods. These, with their respective strengths and limitations, are:
- Self-reported use ever: whether respondents had used specific drugs at some point in their lives, providing useful contextual information when, for example, examining general attitudes to drugs. However, this is not a useful indicator of current drug use or recent trends since it can include people who have used a drug once, perhaps a long time ago;
- Use in the last year: whether respondents had used specific drugs in the year prior to interview. This time frame is generally regarded as the most stable measure of current drug use, especially when analysing trends over time; 12
- Use in the last month: whether respondents had used specific drugs in the month prior to interview. This time frame provides the most up-to-date information on usage. However, since it is a relatively short time period it is more prone to variation, for example, it may miss people who use drugs regularly but who have not done so within the last month.
1.6 Comparing SCJS 2009/10 with BCS 2009/10
Due to the fact that the British Crime Survey ( BCS) 2009/10 self-completion questionnaire was asked of respondents aged between 16 and 59 years while the SCJS was asked of respondents of all ages above 16 years (i.e. including those aged 60 or over), care should be taken when comparing SCJS and BCS data. In this report, where comparisons are made with the BCS 2009/10, the SCJS 2009/10 data have been filtered to exclude those aged 60 years or over.
1.7 Structure of the report
This report looks at self-reported illicit drug use among adults in Scotland. Chapter 2 focuses on prevalence of drug use ever (that is, at least some point in a person's life), at least once in the last year (i.e. the year prior to interview) and at least once in the last month (i.e. the month prior to interview) among all adults aged 16 or over.
It looks at key trends in the use of different types of drugs, comparing findings with the SCJS 2008/09 as well as findings for England and Wales using results from the BCS 2009/10. Variations in self-reported drug use in terms of some key demographic and socio-economic variables are also explored. The chapter concludes by looking at the likelihood of being offered drugs in the last year, again highlighting any demographic and socio-economic differences.
Chapter 3 looks in more detail at the experiences of respondents who reported taking drugs at some point in their lives, firstly looking at self-reported drug use in the last year, followed by use in the month prior to interview. Providing more in-depth analysis, the chapter then looks more specifically at the drug reported as being used most often in the last month, the frequency with which these drugs were taken and the extent of dependency. The ease with which users were able to obtain drugs is explored along with polydrug use; that is, mixing drugs with other drugs or alcohol. The chapter concludes with a look at first experiences of drug taking, including which drug was first taken and at what age.