Preferences for services in a patient's first six months on antiretroviral therapy for HIV in South Africa and Zambia (PREFER): research protocol for a prospective observational cohort study

For patients on HIV treatment in sub-Saharan Africa, the highest risk for loss from care remains the first six months after antiretroviral (ART) initiation, when patients are not yet eligible for differentiated service delivery (DSD) models that offer lower-burden, patient-centred care and thus improve treatment outcomes. To reduce early disengagement from care, the PREFER study will use a sequential mixed-methods approach to describe the characteristics, needs, concerns, and preferences of patients in South Africa and Zambia 0-6 months after ART initiation or re-initiation. PREFER is an observational, prospective cohort study of adults on ART for ≤6 months at 12 public healthcare facilities in Zambia and 18 in South Africa. Its objective is to describe and understand the needs and preferences of initiating and re-initiating ART clients to inform the design of DSD models for the early HIV treatment period, improve early treatment outcomes, and distinguish the barriers encountered by naïve patients from those facing re-initiators. It has four components: 1) survey of clients 0-6 months after ART initiation (identify characteristics and preferences of clients starting ART); 2) follow up through routinely collected medical records for