Female and younger subjects have lower adherence in PrEP trials: a meta-analysis with implications for the uptake of PrEP service to prevent HIV.

<bold>Objective: </bold>To estimate the medicine-taking compliance (MTC) level, explore its facilitators and barriers, and quantify the association between MTC level and pre-exposure prophylaxis (PrEP) protective efficacy in individuals at risk of acquiring HIV being administered oral PrEP.<bold>Design: </bold>Meta-analysis.<bold>Data Sources: </bold>We searched PubMed, Cochrane and Embase databases for published randomized controlled trials (RCTs) pertaining to MTC of oral PrEP for HIV prevention up to 16 January 2017.<bold>Review Methods: </bold>The pooled proportion of MTC and risk ratio (RR) of HIV incidences between intervention group and control group were estimated.<bold>Results: </bold>We identified 10 eligible studies with 24 193 participants. The overall pooled MTC for oral HIV PrEP was 59.9% (95% CI 43.1% to 74.6%). Subgroup analyses revealed that the MTC level of participants aged <30 years was lower than those equal or older than 30 years (34.9% vs 69.6%, p<0.001); those studies that enrolled only women as participants had lower MTC than those only recruiting either only men or both men and women (31.3% vs 71.7% and 31.3% vs 71.0%, all p<0.01). Additionally, the HIV infection risk increased as the MTC level declines, with the incidence RRs being 0.28 (95% CI 0.19 to 0.41), 0.42 (95% CI 0.29 to 0.62) and 0.75 (95% CI 0.45 to 1.25) in the good (≥80%), moderate (60%~80%) and poor (<60%) MTC subgroups, respectively (linear trend test p<0.01).<bold>Conclusion: </bold>According to the pooled proportion, the MTC of oral HIV PrEP is almost moderate, and its proportion in women and younger participants was relatively low. The protective efficacy of oral PrEP for HIV prevention increased with MTC level. These findings indicated that it is necessary to identify measures to enhance MTC of oral PrEP in future clinical usage, especially in women and younger participants with high HIV infection risk. [ABSTRACT FROM AUTHOR]