Feasibility and Preliminary Effectiveness of a Discrete Choice-Based Pre-Exposure Prophylaxis Delivery Model for Female Sex Workers in Uganda

The current PrEP delivery models in Uganda do not fully address the socio-economic, cultural, and logistical challenges faced by female sex workers (FSW), resulting in low adherence, mistrust in the healthcare system, and missed opportunities for effective PrEP care, as reflected in national data. This study evaluated the feasibility and effectiveness of a discrete-choice PrEP delivery model to improve PrEP uptake, adherence, and outcomes among FSWs in Kampala, Uganda. We conducted a discrete choice experiment in October-November 2023 and identified an optimal model combining facility-based, health worker-led, in-person support with short message service (SMS) reminders. From March to May 2024, we implemented a pilot study to assess feasibility and preliminary effectiveness. We recruited 49 FSWs using peer-led snowball sampling at the Most At-Risk Population Initiative (MARPI) clinic at Mulago Hospital. We evaluated effectiveness using a pre-post design, comparing adherence scores at one and two months. Feasibility was measured using six 4-point Likert-scale items (score range 6-24; higher scores = greater feasibility). All 50 participants completed the follow-up. The median age was 27 years (IQR 21-30); most were Christian (86%), had primary education (55%), were single (76%), had sex with males (79%), and were in casual relationships (88%). Median adherence improved from 0.90 (IQR 0.83-0.93) at baseline to 1.00 (IQR 0.97-1.00) at two months. All 50 participants returned for their refill at the 2-month visit. Feasibility was high, with a mean score of 21.26 (SD 1.03). Integrating in-person facility-based support with SMS reminders significantly improved oral PrEP adherence among high-risk FSW. Improved adherence, full retention, and strong feasibility demonstrate the promise of combining face-to-face health care with mobile technology. Future research should examine the long-term effectiveness and scalability of this discrete-choice-informed model to sustain PrEP adherence among FSW.