AOD Project | High-Risk Populations

The high-risk populations component of the Alcohol and other drug monitoring project is intended to provide indicators of patterns of use and substance-related problems within “at-risk” populations. The dataset contains information collected from surveys conducted in two BC cities (Vancouver and Victoria) and is designed to monitor patterns and trends in three specific populations that commonly use illicit drugs (club/party attendees, street-involved youth and street-involved adults).

Ten waves of survey data collection (quantitative and qualitative) were completed in both Vancouver and Victoria: 2008 (Wave 1 & 2), 2009 (Wave 1 & 2), 2010 (Wave 1 & 2), 2011 (Wave 1 & 2) & 2012 (Wave 1 & 2). Data collection ceased in Vancouver in 2012, and is on hiatus in Victoria as of 2017. The recruitment criteria for the street involved adult group were amended in late 2009. Previously, participants were required to be actively using drugs by injection, but the criteria were revised to remove the requirement of injection drug use in order to survey a broader group of people using illicit drugs.

Key findings from this component can be found in facts & stats/substance use in high-risk populations in BC.


The target high-risk populations which were considered of primary interest for this monitoring exercise included ‘club and party drug scenes’ as well as both adolescent and adult injection drug users. Drawing from international high-risk monitoring systems including those implemented in Australia and the European Union, research in both Vancouver and Victoria featured the administration of a lengthy monitoring instrument. This instrument was administered face-to-face in an interview format with trained research assistants running through each item and then recording responses on the survey instrument. This method was selected over a more traditional “self-complete” approach in order to maintain the fidelity of the survey design and to reduce the number of “missing data”. This approach also permitted the inclusion of more complex items.

Recruitment criteria reflecting methodological conventions in other international high-risk monitoring systems (see Shand et al 2003), specific recruitment criteria were devised for each population of interest to ensure the collection of timely and useful research data. Given the strong interest in local drug markets and drug use cultures, participants for each of the three cohorts of interest were required to have lived in the research site for at least six months. Similarly, for each cohort participants were required to have used drugs other than alcohol and tobacco at least once per month in each of the last six months. For the adult injection drug use cohort, participants were required to have injected a drug at least once per month in each of the past six months. For the two “adult” cohorts (groups 1 and 2 noted above) eligible participants included individuals aged 19 years and older; for the adolescent cohort, participants were required to be aged between 15 and 24 years of age. With respect to each of these recruitment criteria, screening instruments were developed to test for these criteria at intake and prior to the completion of all information and participant consent protocols.


The sampling of these populations relied on targeted participant selection in order to achieve representation for this group, yet was cross-sectional over time (i.e., no cohort methods). Various efforts were made to recruit a diverse sentinel population from a range of settings in each cohort in each of the two study sites. This was achieved through the combined use of convenience, purposive and snowball sampling methods. To enhance the cross-sectional nature of these samples, it was determined in each instance that no more than 50% of the entire sample ought to be recruited through snowballing methods. In turn, a minimum of five “start points” for this snowballing was deemed appropriate, though no more than three individuals were recruited through each snowballing “point” or contact. This approach was designed in order to enhance the diversity of the sample recruited through snowballing methods and remains consistent with established methodological guidelines (see Biernacki and Waldorf 1981).

In addition to snowballing techniques, specific fixed site recruitment strategies were designed for each completed cohort. Recruitment sites were selected on the basis of their representativeness of different sectors or elements of the target population. For example, for the “club drugs” cohort, five distinct nightclub and/or bar sites were identified at which outreach recruitment took place. These venues were deemed to be representative or indicative of different sub-cultures within the local “night-time economy” on the basis of advice from local key experts and other stakeholders. Similarly, two sites were selected for recruitment for the adult IDU cohort. The advantage with such fixed site recruitment is that it enables more consistent comparisons to be made over time as individuals are recruited at regular intervals from the same sites (see also Strauss and Corbin 1998).

To facilitate both convenience as well as snowball sampling methods advertisements for each research cohort were placed in bars, clubs and cafes, at needle exchanges and community health centres across the study sites. Additionally, many participants found out about the survey through word of mouth from other participants who had completed the survey. About 11% of IDU participants were secondary referrals (i.e. from snowball sampling methods) compared to about 17% for the club drugs sample. Participants for the club drug study were recruited through diverse methods including advertisements on local club and rave internet sites, word of mouth and local personal networks. All participants received compensation for their time and any travel expenses they may have accrued in the form of a $20 cash honorarium.

Survey Instruments and Procedures

For the club drugs sample, a standardized quantitative and qualitative protocol was administered in each primary target population in each of the two study sites (Vancouver and Victoria). Nine in-depth drug categories were covered: ecstasy cocaine, crack, crystal meth, LSD, heroin, mushrooms, GHB, and ketamine. Each protocol included items on drug use and related risk behaviors; drug markets, price, availability, perceptions of quality in these markets and trends over time; perceptions of risks and harmful effects of drug use; health and socio-economic indicators. Interviews took approximately 60 to 90 minutes to complete.

The IDU sample followed a similar protocol with both quantitative and qualitative items included. Items pertaining to recent drug use behaviours (yesterday and last weekend) were assessed as well as items looking at local drug markets for cocaine, crack, crystal meth and heroin. The two survey instruments were each designed with the broader national study model in mind. In particular, efforts were made to design a standardized survey that could be implemented across various sites and provinces throughout Canada. To this end, local and/or idiosyncratic drug references and questions were omitted in preference for more generic and inclusive terms, references and item wording. This was primarily achieved through a careful cross-referencing of each survey instrument with comparable national and provincial survey instruments. Wherever possible, standardized items were selected to improve the relevance and utility of each instrument. A training manual for interviewers was also developed which will aid the standardization of these instruments.


Note: in 2015, a unified survey instrument was created for CRDUS, CASSIDU and CYSSIDU.

Canadian Recreational Drug Use Survey–BC [CRDUS Survey] (last updated January 2016).

Canadian Adult Sentinel Survey of Illicit Drug Use–BC [CASSIDU Survey] (last updated January 2016).

Canadian Youth Sentinel Survey of Illicit Drug Use–BC [CYSSIDU Survey] (last updated January 2016).


John Carsley
David Marsh
Tim Stockwell
Clifton Chow
Kate Vallance
Andrew Ivsins
Cameron Duff
Warren Michelow

Resource Library

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Biernacki, P and Waldorf. D. 1981. “Snowball Sampling: Problems and Techniques of Chain Referral Sampling”. Sociological Methods Research. 10(141-163).

Duff, C. 2005. ‘Party Drugs and Party People: Examining the ‘Normalization’ of Recreational Drug Use in Melbourne, Australia’. International Journal of Drug Policy. 16:3(161-170).

Duff, C. 2004. “Drug use as a 'practice of the self': Is there any place for an 'ethics of moderation' in Contemporary Drug Policy”? International Journal of Drug Policy. 15:5/6. (385-393)

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Mounteney J, Leirvåg S-E (2004). ‘Providing an earlier warning of emerging drug trends: the Føre Var System’. Drugs: Education, Prevention and Policy, 11(6),449-471.

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Shand F, Topp L, Darke S, Makkai T, Griffiths P (2003). ‘The monitoring of drug trends in Australia’. Drug and Alcohol Review, 22, 61-72.

Stimson GV, Fitch C, Rhodes T, Ball A. (1999). ‘Rapid assessment and response: methods for developing public health responses to drug problems’. Drug and Alcohol Review, 18, 317-325.

Strauss, A., and J. Corbin (1998). Basics of Qualitative Research: Techniques and Procedures for Developing Grounded Theory (2nd ed.). Thousand Oaks, CA: Sage.

Thurman VA (2001). ‘The point of triangulation’. Journal of Nursing Scholarship, 33(3), 253-8.

Topp L, McKetin R (2003). ‘Supporting evidence-based policy-making: a case of the study of the Illicit Drug Reporting System in Australia’. Bulletin on Narcotics, 54(1-2), 23-30.

United Nations International Drug Control Programme (2002). Developing an Integrated Drug Information System. Global Assessment Programme on Drug Abuse Toolkit Module 1.

Wood, E., Stoltz, J., Montaner, J. S., & Kerr, T. (2006). Evaluating methamphetamine use and risks of injection initiation among street youth: The ARYS study. Harm Reduction Journal, 3(18),

Zeisser, C., Thompson, K., Stockwell, T., Duff, C., Chow, C., Vallance, K., Ivsins, A. Michelow, W., Marsh, D, Lucas, P. (In Press). A “standard joint”? The role of quantity in predicting cannabis-related problems. Addiction Theory and Research.