Early disengagement from HIV pre-exposure prophylaxis services and associated factors among female sex workers in Dar es Salaam, Tanzania: a socioecological approach

IntroductionPre-exposure prophylaxis (PrEP) is an effective HIV prevention tool when taken as prescribed. However, suboptimal use may challenge its real-life impact. To support female sex workers in their efforts to prevent themselves from HIV, it is essential to identify factors that contribute to early disengagement from PrEP care. In this study, we aimed to estimate the risk of early disengagement from PrEP services among female sex workers in Tanzania and associated factors using a socioecological model as a guiding framework.MethodsThe study was conducted as part of a pragmatic mHealth trial for PrEP roll-out in Dar es Salaam in 2021. We estimated the risk of early disengagement, defined as not presenting for the first follow-up visit (within 56 days of enrolment), and its associations with individual, social, behavioural and structural factors (age, self-perceived HIV risk, mental distress, harmful alcohol use, condom use, number of sex work clients, female sex worker stigma and mobility) using multivariable logistic regression models, with marginal standardisation to obtain adjusted relative risks (aRR).ResultsOf the 470 female sex workers enrolled in the study, 340 (74.6%) did not attend the first follow-up visit (disengaged). Mental distress (aRR=1.14; 95% CI 1.01 to 1.27) was associated with increased risk of disengagement. Participants who reported a higher number of clients per month (10-29 partners: aRR=0.87; 95% CI 0.76 to 0.98 and >= 30 partners: aRR=0.80; 95% CI 0.68 to 0.91) and older participants (>= 35 years) (RR=0.75; 95% CI 0.56 to 0.95) had a lower risk of disengagement.Conclusions and recommendationsEarly disengagement with the PrEP programme was high. Mental distress, younger age and having fewer clients were risk factors for disengagement. We argue that PrEP programmes could benefit from including mental health screening and treatment, as well as directing attention to younger sex workers and those reporting fewer clients.