Preferences for clinical trial participation among people who use drugs in rural Oregon and Appalachian Ohio

Background: Rural communities in the United States face significant challenges in participating in clinical trials, despite being heavily impacted by opioid and injection drug use epidemics. Barriers such as transportation, stigma, and limited resources often deter rural people who use drugs (PWUD) from engaging in research. Discrete choice experiments (DCEs) can help identify trial design features that support participation by eliciting participant preferences. Methods: We selected DCE attributes and attribute levels through literature review and qualitative interviews. Peer-based Retention of People who Use Drugs in Rural Research (PROUD-R²) study participants in rural Oregon and Appalachian Ohio completed the DCE at their baseline visit. We used conditional logit models to estimate preference weights. Results: Overall, 478 participants completed the DCE and most (71 %; n = 337) were from Oregon. The majority were male (63 %; n = 299) and were white (85 %; n = 404). Overall, transportation support, particularly travel reimbursement (preference weight=0.87; p < 0.01; relative utility versus videochat=1.15), was the most valued feature for clinical trial participation. Participants also preferred shorter appointments (relative utility of 1-hour versus 3-hour=0.44) and evening over morning appointments (relative utility=0.29). Conclusions: Rural PWUD preferences underscore the need to redesign clinical trial protocols with equity and feasibility at the forefront. Direct transportation support emerged as the top priority, reflecting how rural poverty and isolation limit access. Preferences for shorter and later-day appointments suggest a need for low-burden, flexible scheduling. Incorporating participant-centered features can improve trust, enrollment, and retention, ensuring rural PWUD are included in research that addresses their needs.