Background: Female sex workers (FSW), men who have sex with men (MSM) and young women (YW) account for majority of new infections in Kenya. Oral PrEP effectively protects against HIV infection but data on PrEP retention and influencing factors in real-world settings is limited. We present data on retention on PrEP in a prospective oral PrEP demonstration project in Kenya.
Methods: Between August 2015 and October 2016, we enrolled 1585 participants; 528(33%) FSW, 438(28%) MSM and 619(39%) YW; on oral PrEP. Two public and four private health facilities were used as points of care, with monthly PrEP refill and adherence/risk behavior counselling visits. Follow up duration was one year and participants did not receive reimbursements. Retention was defined as returning for PrEP refill as scheduled and assumed to imply PrEP use. Reasons for drop-out and continuous use were documented through facility registers and in-depth interviews and focus group discussions with PrEP users and health care workers (HCWs). Data was analysed using STATA (quantitative) and NVivo (qualitative).
Results: Retention at one, three and six months was 40.3%, 26.3% and 14% for FSW; 32.9%, 21.7% and 14.8% for MSM and; 25.7%, 16.5% and 9.5% for YW. For all populations, the instantaneous hazard rate of terminating PrEP use was lowest at twenty weeks. FSW < 23 years were more likely to drop out compared to older FSW (HR 0.76 (95% CI: 0.60 to 0.97) p < 0.029). No age variations were observed among MSM and YW. Reasons for choosing to stop using PrEP included reduced self-perception of risk, sexual partner on successful antiretroviral therapy, community stigma, PrEP myths and misconceptions, risk of social harm, negative attitude from HCWs, challenges accessing study site and tedious procedures at health facilities. Motivators for continuous PrEP use include peer/guardian/partner support, access to combination HIV prevention services and social responsibility.
Conclusions: In our context, we observed high attrition from oral PrEP use by all populations but especially by young women. There are individual, community and health system barriers and enablers of continuous PrEP use. Most of these are modifiable and need to be considered by countries and programs scaling up oral PrEP.

Retention on oral pre-exposure prophylaxis (PrEP)
[Retention on oral pre-exposure prophylaxis (PrEP)]