Evaluating a Pharmacy-Led PrEP Refill Model on Continuation Rates in Lusaka's Serodiscordant Couples: A Working Paper

In Zambia, pre-exposure prophylaxis (PrEP) is a key HIV prevention tool for serodiscordant couples. Maintaining high continuation rates beyond initial uptake remains a programme challenge, as conventional clinic-based refill models can pose logistical and time barriers. This working paper evaluates the impact of a differentiated service delivery model—a pharmacy-led PrEP refill programme—on continuation rates among serodiscordant couples in Lusaka. It aims to assess the model’s feasibility and preliminary effectiveness compared to standard clinic-based care. A mixed-methods, observational study was conducted. Quantitative data on refill visits and continuation were collected from programme registers for couples enrolled in the pharmacy-led model and a comparison group receiving standard care. A subset of clients and providers participated in in-depth interviews to explore experiences and perceptions. Preliminary analysis indicates a positive association between the pharmacy-led model and improved continuation. Clients using pharmacy refills demonstrated a 15-percentage point higher continuation rate at six months compared to the standard care group. Qualitative themes highlighted reduced waiting times and perceived lower stigma as key facilitators. The pharmacy-led refill model shows promise for improving PrEP continuation among serodiscordant couples in this setting by addressing common barriers associated with clinic-based care. It represents a viable strategy for health systems to optimise service delivery. Programmes should consider piloting and scaling pharmacy-led PrEP refills within differentiated service delivery frameworks. Further operational research is needed to assess long-term outcomes, cost-effectiveness, and optimal integration into national HIV prevention programmes. HIV prevention, pre-exposure prophylaxis, differentiated service delivery, adherence, Zambia, key populations, task shifting This working paper provides early evidence from the Zambian context on a pharmacy-led PrEP refill model, contributing to the discourse on practical, client-centred approaches to improve prevention outcomes for serodiscordant couples.