Trial of an mHealth intervention to improve HIV prophylaxis for female sex workers, United Republic of Tanzania.

Objective: To evaluate the effect of a mobile health (mHealth) intervention on early retention of female sex workers in human immunodeficiency virus (HIV) pre-exposure prophylaxis services in the United Republic of Tanzania.

Methods: The study involved 783 female sex workers: 470 from Dar es Salaam who were given the mHealth application (app) in addition to standard HIV pre-exposure prophylaxis (intervention arm), and 313 from Tanga who received pre-exposure prophylaxis alone (control arm). Participants were recruited using respondent-driven sampling and followed up for 12 months. Early retention was defined as attending a pre-exposure prophylaxis follow-up clinic within 28 days of an appointment scheduled for 1 month after starting treatment. To assess if the app led to higher retention, we conducted intention-to-treat and per-protocol analyses using a regression model adjusted by inverse probability weighting.

Findings: Early retention in HIV pre-exposure prophylaxis care was observed in 27.6% (130/470) of participants in the intervention arm and 20.1% (63/313) in the control arm. In the adjusted, intention-to-treat analysis, early retention was observed in 29.4% in the intervention arm and 17.7% in the control arm (risk difference: 11.8 percentage points; 95% confidence interval: 5.3-18.3).

Conclusion: Early retention in HIV pre-exposure prophylaxis care was significantly greater among female sex workers in the United Republic of Tanzania who used the app than in those who did not. Nevertheless, more than two thirds of sex workers using the application did not attend follow-up services after 1 month, suggesting that additional interventions are needed.