A Social Scientific Investigation of Randomized Controlled Trial Participation in Addictions Research

Date Commenced:
Project Status
Expected Date of Completion:
Project Supporters

Canadian Institutes of Health Research

Currently recruiting
image - Kirby Logo On White 30

About the Project

Illicit drug use is a major driver of severe health and social harms in Canada and globally and there remain significant gaps in our ability to address the associated human, social and economic costs. In an attempt to fill these gaps, several RCTs are being initiated in Vancouver to examine novel addiction treatment and harm mitigation strategies including an initial focus on testing the efficacy of candidate pharmacotherapies for cocaine dependence. Given the social, clinical and ethical issues related to RCT research participation by vulnerable populations, including people who use drugs (PWUD), there is a need for research which examines the individual, social, structural and ethical dimensions of addiction RCT participation by this group.


Previous RCTs among marginalized populations have identified issues of significant consequence to experiences of trial participation and the effective and ethical execution of RCTs. These issues have significantly impacted the success of trial-based research but have focused on individual and trial-level attributes that have not been fully explored in the unique context of actual addiction RCTs.


This project aims to:

1) Examine the individual, social and structural determinants of motivations, barriers and willingness to participate in addiction RCTs

2) Assess the individual, social and structural correlates of RCT trial preparedness

3) Explore attitudes about and experiences of addiction RCT participation, before, during, and following trial completion

4) Identify individual, social and structural determinants of protocol adherence and trial participation completion.

By partnering with addiction RCTs, the study will focus on actual rather than hypothetical research scenarios and evaluate participation dimensions longitudinally from pre-trial preparedness through to post-trial reflection.

Design & Method

Using a mixed methods approach, we will aggregate findings from qualitative and quantitative research, identify the determinants of RCT participation among PWUD and identify gaps and generate new hypotheses to be tested in subsequent studies. Determinants of RCT retention and adherence (defined as ≥85% of all possible follow-ups completed) will be assessed using generalized linear mixed-effects models to identify the effects of hypothesized individual, social and structural determinants of RCT participation as covariates of interest. In terms of comparative analyses we will descriptively assess the representativeness of actual trial participants relative to hypothetical trial participants and compare hypothetical and actual trial participants across key measures of study eligibility such as intensity of substance use, residency, co-morbidities and outstanding warrants. We will assess differences between hypothetical and actual dimensions of RCT participation, including motivations, barriers, CTL and self-efficacy to complete trial protocols. Comparative analyses of trial preparedness will employ Mann-Whitney U-tests to examine differences in median scores between hypothetical and actual RCT participants. Bivariate and multivariate ordinary least squares regression models with CTL and self-efficacy to complete trial protocols as outcome variables and actual trial participation as the main covariate of interest will further describe relative differences in these test scores. Consistent with parallel mixed model approaches, following data collection completion and preliminary analyses we will cross-compare quantitative results with qualitative findings for consistency, re-evaluate qualitative data for their ability to identify explanatory mechanisms that may elucidate quantitative findings and examine inconsistent or contradictory qualitative evidence that may underscore unanticipated null findings.


In progress


By identifying individual, social and structural impacting trial recruitment, retention and protocol adherence in addictions RCT research, the study will promote the effective and ethical conduct of these trials and the probability of their success. In addition, results will inform the conduct of future addiction trials in Vancouver and globally, maximising their effectiveness and ensuring ethical, informed and meaningful involvement by PWUD.


Peer-reviewed publications, conference presentations and reports

Project Members
image - 1340850769 Lm Work Photo
Professor and Program Head and NHMRC Senior Research Fellow
Ph +61 (0)2 9385 0936
Other Investigators

Lindsey Richardson, Thomas Kerr, Evan Wood, Julio Montaner, Will Small, Peter Newman, Rod Knight

Project Collaborators: External

British Columbia Centre for Excellence in HIV/AIDS, University of British Columbia, University of Toronto

Project Contacts

Related Projects