Exploring the Contextual Factors Influencing the Implementation and Effectiveness of Community Health Worker–Led Malaria Community Case Management in Kailahun District, Sierra Leone

Background. CHW-led malaria community case management (CCMm) extends services to rural, hard-to-reach communities in Kailahun District, Sierra Leone, where the malaria burden is heaviest; yet the same standardised intervention produces different outcomes across chiefdoms. This paper asks how contextual conditions enable or block the mechanisms through which CHWs produce outcomes. Methods. A qualitative realist evaluation using the Context–Mechanism–Outcome framework drew on six key informant interviews, three CHW contextual interviews and six focus group discussions (58 caregivers), analysed thematically with realist-informed coding and text-network analysis. Results. Contextual influences spanned nine domains: geographic, health-system, socio-cultural, gender, economic, governance, programmatic, historical and market. Traditional authority engagement and geographic accessibility were decisive across every tier, and the same conditions acted as facilitators when present and barriers when absent. Conclusion. Context is constitutive, not background; policy should stabilise a small set of conditions above all supply continuity and traditional authority engagement that determine whether its mechanisms fire.