Contingency Management and Pre-Exposure Prophylaxis Adherence Support Services (CoMPASS): A hybrid type 1 effectiveness-implementation study to promote HIV risk reduction among people who inject drugs

HIV disproportionally affects persons who inject drugs (PWID), but engagement with HIV pre-exposure prophylaxis (PrEP) is low. We describe the rationale and study design for a new study, "Contingency Management and Pre-Exposure Prophylaxis (PrEP) Adherence Support Services (CoMPASS)," a hybrid type 1 effectiveness-implementation trial to promote HIV risk reduction among PWID.In four community-based programs in the northeastern United States, PrEP-eligible PWID (target n = 526) are randomized to treatment as usual or Contingency Management (CM) and, as indicated, stepped up to PrEP Adherence Support Services (CoMPASS) over 24 weeks. During CM sessions, participants receive timely tangible rewards for verifiable activities demonstrating 1) PrEP initiation and adherence, and 2) engagement with medications for opioid use disorder (MOUD) and other OUD-related care. Participants who do not have high levels of biomarker-confirmed PrEP adherence at week 12 will be stepped up to receive PrEP Adherence Support Services (PASS) consisting of strengths-based case management over 12 weeks. Interventions are delivered by trained PrEP navigators, staff embedded within the respective sites. The primary outcome is sustained PrEP adherence by dried blood spot testing at 24 weeks. To inform future implementation, we are conducting implementation-focused process evaluations throughout the clinical trial.Results from this protocol are anticipated to yield novel findings regarding the impact and scalability of CoMPASS to promote HIV prevention among PWID in partnership with community-based organizations. http://ClinicalTrials.gov identifier: NCT04738825.