Trust in research physicians as a key dimension of randomized controlled trial participation in clinical addictions research.

Background: In the development of pharmacotherapies for substance use disorders, willingness to participate in randomized controlled trials (RCTs) among people who use drugs (PWUD) is influenced by numerous social and structural factors. Considering the criminalization and stigma experienced by PWUD and range of experiences in healthcare and research, PWUD may vary in their trust of health providers, health research physicians, or medical research processes. We therefore examine associations between trust in these three domains and willingness to participate in a hypothetical RCT for a novel pharmacotherapy for stimulant use among PWUD. Methods: Data were derived from a cross-sectional questionnaire administered to participants using crack and/or cocaine from three cohort studies of PWUD in Vancouver (N = 229). Results: A majority of participants were "definitely" or "probably" willing to participate in an RCT. In multivariable ordinal regression, trust in research physicians was positively associated with willingness to participate, while trust in primary care providers or medical research processes were not significantly associated. Conclusions: This data suggests trust in research physicians plays a role in RCT decision-making among PWUD, while trust in healthcare providers and research processes appears less relevant. These findings highlight opportunities for supporting RCT recruitment by building trust in research physicians.