Outcomes of a community-based antiretroviral therapy programme for key populations living with HIV in Benue State, Nigeria: protocol for a realist evaluation

INTRODUCTION: Key populations (KP) living with HIV are underserved and often face social and health system barriers to HIV care. To optimise access to quality HIV services among KP, the WHO recommended community-based approaches to HIV service delivery for KP. However, to inform the successful rollout and scale-up of community-based antiretroviral therapy service delivery models for KP (KP-CBART), there is a need to study the programme implementation. This study aims to evaluate the outcomes of KP-CBART in Benue State Nigeria using a realist impact evaluation approach. Our evaluation question is: what are the mechanisms and context conditions that drive successful community-based implementation and how do these lead to better retention in care, treatment adherence and viral suppression among which categories of KP? METHODS AND ANALYSIS: This study will be conducted in three phases, relying on a mixed-method design and following the realist evaluation cycle. The first phase is the development of the initial programme theory grounded in a scoping review, programme and policy document review and in-depth interviews with key stakeholders. In phase 2, findings from case studies of KP-CBART programme implementation in one Nigerian state are used to test the initial programme theory and to refine it. The quantitative part is a retrospective cohort study. All HIV-positive KP clients enrolled into the KP-CBART between 2016 and 2020 will be included in the study. While maximum variation and data saturation will inform sample size for the qualitative part, an estimated 90 purposively selected study participants will be interviewed. In phase 3, findings will be synthesised into a middle-range theory through cross-case analysis. The heuristic intervention, context, agents, mechanisms and outcomes (ICAMO) tool will be used to refine the initial programme theory. ETHICS AND DISSEMINATION: The study protocol was approved by the Institutional Review Boards of APIN Public Health Initiatives (IRB022-FR), Institute of Tropical Medicine Antwerp (1503/21), and the Benue State Ministry of Health and Human Services (MOH/STA/204/VOL1/154). Written informed consent will be obtained from all study participants. Study results will be disseminated through stakeholders meeting, peer-reviewed journals and conferences.