Retention in clinical trials after prison release: results from a clinical trial with incarcerated men with HIV and opioid dependence in Malaysia

Background: Study retention is a major challenge in HIV clinical trials conducted with persons recruited from correctional facilities. Objective: To examine study retention in a trial of within-prison methadone initiation and a behavioral intervention among incarcerated men with HIV and opioid dependence in Malaysia. Methods: In this 2x2 factorial trial, 296 incarcerated men with HIV and opioid dependence were allocated to (1) an HIV risk reduction intervention, the Holistic Health Recovery Program for Malaysia (HHRP-M), (2) pre-release methadone initiation, (3) both interventions, or (4) standard care (NCT02396979). Here we estimate effects of these interventions on linkage to the study after prison release and completion of post-release study visits. Results: Most participants (68.9%) completed at least one post-release study visit but few (18.6%) completed all 12. HHRP-M was associated with a 13.5% (95% confidence interval (CI): 3.8%, 23.2%) increased probability of completing at least one post-release study visit. Although not associated with initial linkage, methadone treatment was associated with an 11% (95% CI: 2.0%, 20.6%) increased probability of completing all twelve post-release study visits. Being subject to forced relocation outside Kuala Lumpur after prison release decreased retention by 43.3% (95% CI: -51.9%, -34.8%). Conclusion: Retaining study participants in HIV clinical trials following prison release is challenging and potentially related to the broader challenges that participants experience during community reentry. Researchers conducting clinical trials with this population may want to consider methadone and HHRP as means to improve post-release retention, even in clinical trials where these interventions are not being directly evaluated.