Long-acting HIV pre-exposure prophylaxis adherence and discontinuation: a global systematic review and meta-analysis

Background: Long-acting HIV pre-exposure prophylaxis (PrEP) may overcome adherence and discontinuation challenges facing oral PrEP, which remain unsystematically reviewed. This study aimed to synthesize the evidence on long-acting PrEP adherence and discontinuation. Methods: We conducted a systematic review and meta-analysis of studies published from database inception to July 1, 2026 in PubMed, Web of Science, EMBASE, and Cochrane Library. Eligible studies reported adherence (on-time doses receipt at time points, e.g., at 2 months) or discontinuation (stopping doses or loss to follow-up within a time period, e.g., within 6 months) of long-acting PrEP, including long-acting injectable (LAI) and intravaginal ring (IVR) PrEP. Non-longitudinal designs and non-English publications were excluded. We used random-effects meta-analyses to pool estimates. Subgroup analyses were conducted by population, region, and study design. Interpretation: Adherence to LAI-PrEP remained high through 12 months, with the best adherence being observed in clinical trials, which serve as upper-bound benchmarks. Compared to LAI-PrEP, IVR-PrEP had lower adherence and higher discontinuation. Efforts facilitating longer-term adherence warrant research. Funding: This study was supported by the National Key R&D Program of China.