Enhanced peer PrEP referral with HIV self-testing did not increase PrEP initiation but increased HIV testing among Kenyan AGYW.

BACKGROUND: Adolescent girls and young women (AGYW) in Africa experience high HIV acquisition risk and low engagement in prevention services. Knowledge of HIV-negative status paired with peer support might motivate AGYW-who are highly socially connected-to initiate HIV prevention services, including pre-exposure prophylaxis (PrEP). METHODS AND FINDINGS: We conducted a randomized controlled trial (ClinicalTrials.gov: NCT04982250) of AGYW peer networks in Central Kenya. Index peers aged 16-24 years who had used oral PrEP in the past 12 months were randomized 1:1 to: (1) enhanced peer referral: group training on PrEP referral strategies and delivery of HIV self-testing (HIVST) kits (n = 8 kits, 2 kits/peer); or (2) standard peer referral: informal PrEP referral strategies. Index peers were encouraged to refer four peers who could benefit from PrEP. Outcomes for referred peers-PrEP initiation (primary), PrEP continuation (i.e., month one refills), and HIV testing (any form following referral)-were reported by index peers three months later. Implementation outcomes and costs were also assessed. Risk differences (RDs) were estimated using generalized linear mixed-effects regression models with study group fixed effects and index peer random effects. From May 3, 2023 to February 16, 2024, 316 index peers were screened and 82 enrolled/randomized (median age 22 years, IQR 20-23): 40 to the enhanced group and 42 to the standard. No index peers were lost to follow-up. Index peers reported outcomes for 241 referred peers (median age 22 years, IQR 21-24): 137 in the enhanced group and 104 in the standard. At follow-up, there were no significant differences in PrEP initiation between the enhanced group (30%, 41/137) and the standard (41%, 41/104; RD -6%, 95% CI [-26%, 11%], p = 0.51). Enhanced peer referral was not associated with PrEP continuation (RD 1%, 95% CI [-10%, 13%], p = 0.82) but was associated with increased recent HIV testing (RD 39%, 95% CI [24%, 54%], p < 0.001). Three referred peers, all in the enhanced group, tested HIV-positive; two social harms (verbal abuse among index peers, one in each group) were reported. Index and referred peers in both study groups found enhanced peer referral acceptable and feasible, but it cost almost eight times more per peer referred to PrEP than standard referral ($23 versus $3 USD). Relying on index peers to report outcomes for referred peers was a study limitation. CONCLUSIONS: Enhanced peer PrEP referral with training and HIVST delivery did not increase PrEP initiation among Kenyan AGYW but was associated with increased HIV testing, suggesting opportunities to combine peer-delivered HIVST with additional implementation strategies to improve AGYW's PrEP engagement.