Evaluating the effectiveness of facility-based and community-based PrEP delivery models for HIV prevention among key populations in Uganda: a propensity score matching approach

Abstract

Background: HIV remains a major public health concern in Uganda, with new infections disproportionately affecting key and priority populations such as female sex workers, clients of sex workers, boda-boda riders, and adolescent girls and young women. Although the Ministry of Health has adopted both facility-based and community-based models to expand access to oral preexposure prophylaxis (PrEP), gaps persist in retention, adherence, and continuation. Evidence directly comparing the effectiveness of these two delivery approaches in routine program settings remains limited. The goal of this study was to compare the effectiveness of facility-based versus community-based PrEP delivery models in supporting retention, adherence, and HIV seroconversion among clients at Kasangati Health Centre IV. Methods: This was a comparative observational study that applied propensity score matching, to secondary data extracted from the HIV Prevention Tracker using a structured data abstraction tool aligned with national PrEP indicators. The study included all clients initiated on oral PrEP at Kasangati Health Centre IV between January and December 2024, representing key and priority populations who were HIV-negative at initiation and had follow-up records. Because clients were not randomly assigned to delivery models, the community-based model served as the exposure group and the facility-based model as the comparison group. To minimise baseline differences, Propensity Score Matching using 1:1 nearest-neighbor matching without replacement was performed based on age, sex at birth, and population category, yielding a matched sample of 234 clients (117 per model). Outcomes included retention (≥2 PrEP visits in 12 months), adherence (≥95% pill-taking as documented at visits), and HIV seroconversion (any new HIV-positive result during follow-up). After matching, logistic regression was used to estimate the Average Treatment Effect on the Treated (ATT), comparing outcomes between community and facility delivery models. Results: The two matched groups were similar in age distribution with a mean age of 27 years, sex, and population category. After matching, retention did not significantly differ between models (facility 54.7% vs community 52.1%; aOR = 1.15; 95% CI: 0.58–2.27; p = 0.69). Adherence was uniformly high in both models. Crude HIV seroconversion was higher in the facility model (22.2%) compared to the community model (0.9%); however, this difference was not statistically significant after adjustment (aOR = 1.67; 95% CI: 0.32–8.73; p = 0.53). The facility model served a higher proportion of AGYW, while the community model predominantly served sex workers and clients of sex workers. Conclusion: Both service delivery models achieved high adherence and comparable retention, demonstrating that community-based PrEP delivery is as effective as facility-based delivery in real-world conditions. The higher crude seroconversion in facility settings highlights the need for contextual investigation into risk factors among facility clients. Given the comparable effectiveness, future evaluations should assess the cost-effectiveness and coverage benefits of maintaining both models within Uganda’s differentiated PrEP delivery framework.