How a menu of adherence support strategies facilitated high adherence to HIV prevention products among adolescent girls and young women in sub-Saharan Africa: a mixed methods analysis.

INTRODUCTION: Effective use of pre-exposure prophylaxis (PrEP) has been low among adolescent girls and young women (AGYW) in sub-Saharan Africa. The MTN-034/REACH trial offered AGYW a menu of adherence support strategies and achieved high adherence to both daily oral PrEP and the monthly dapivirine vaginal ring. Understanding how these strategies promoted product use could inform the design of adherence support systems in programmatic settings. METHODS: REACH was a randomized crossover trial evaluating the safety of and adherence to the ring and oral PrEP among 247 HIV-negative AGYW (ages 16-21) in South Africa, Uganda and Zimbabwe from January 2019 to September 2021 (NCT03593655). Adherence support included monthly counselling sessions with drug-level feedback (DLF) plus optional daily short message service (SMS) reminders, weekly phone or SMS check-ins, peer support clubs, "peer buddies" and additional counselling. Counsellors documented adherence support choices and counselling content on standardized forms. Through focus groups, serial in-depth interviews (IDIs) and single IDIs (n = 119 total), we explored participants' experiences with adherence support and how it encouraged product use. RESULTS: Participants received counselling at nearly all visits. DLF was provided at 54.3% of sessions and, across sites, 49%-68% received results showing high adherence for oral PrEP, and 73%-89% for the ring. The most popular support strategies were in-person clubs and weekly calls, followed by online clubs, additional counselling and SMS. Preferences differed across sites but were similar for both products. Qualitative results demonstrated that the REACH strategies supported adherence by providing information about HIV and PrEP, continually motivating participants, and supporting the development of behavioural skills and self-efficacy, aligning with the Information, Motivation, and Behavioural Skills (IMB) model. Effectiveness was supported by three foundational pillars: strong interpersonal relationships with counsellors; ongoing, easily accessible support and resources; and establishing trust in the counsellors and study products through counsellor relationships, peer-to-peer exchange and DLF. CONCLUSIONS: Implementation programmes could support effective PrEP use by offering a small menu of counsellor- and peer-based support options that are youth-friendly and developmentally appropriate. The same menu options can support both ring and oral PrEP users, though content should be tailored to the individual products.