Effect of an mHealth intervention on retention in HIV pre-exposure prophylaxis services among female sex workers: Preliminary evidence of the use of the app in Dar es Salaam, Tanzania.

Background: Mobile health (mHealth) applications have been reported to be effective in promoting access and adherence to health services. However, knowledge about their effect on retention in HIV preventive services among at-risk populations in sub-Saharan Africa is limited.

Objective: We aimed to evaluate the effect of the mHealth application on retention in HIV pre-exposure prophylaxis (PrEP) services among female sex workers in Dar es Salaam, Tanzania.

Methods: We used respondent-driven sampling to recruit female sex workers eligible for PrEP and who owned a smartphone. All study participants were provided with a smartphone application ( app) aiming to promote PrEP use through medication reminders, easy access to PrEP information, online consultations with a doctor and/or peer educator, and online discussions between PrEP users. The effect of optimal use of the app on retention in PrEP services at 1-month was modelled using log-binomial regression.

Results: A total of 470 female sex workers with a median age of 26 (interquartile range: 22-30) years were recruited. Overall, 27.7% of female sex workers were retained in PrEP services at 1 month. Retention was twice as high among optimal users of the app than among sub-optimal users (adjusted risk ratios = 2.00, 95% confidence interval (CI): 1.41-2.83, p < 0.001).

Conclusion: The optimal use of the mHealth application was significantly associated with higher retention in PrEP services among female sex workers in Dar es Salaam.