Implementation Science Analysis of the Integrated Community Case Management Programme for Childhood Illness in Adamawa State, North East Nigeria: A Realist Evaluation

The Integrated Community Case Management (iCCM) programme trains community health workers to manage childhood pneumonia, diarrhoea, and malaria at community level, bridging the healthcare access gap for children in rural and underserved settings. Despite national adoption in Nigeria, iCCM effectiveness varies substantially across contexts, and the mechanisms driving this variation remain theoretically underdeveloped. This realist evaluation examines what works, for whom, in what circumstances, and how within the iCCM programme in Adamawa State, North East Nigeria. Initial programme theory was developed through systematic review of iCCM literature and stakeholder theory-building workshops. Empirical testing employed a sequential mixed-methods design combining routinely collected iCCM programme data from 124 villages over 36 months (2021 to 2023), 40 in-depth interviews with community health workers and caregivers, and 12 focus group discussions with community leaders. Six context-mechanism-outcome configurations were identified as explanatory of programme success or failure. Programmes achieving the highest case detection and treatment rates were characterised by community trust built through regular community health worker presence, adequate drug resupply cycles, and female community health worker deployment in communities with gender norms restricting male-female healthcare interaction. Communities with fragmented social structures post-conflict demonstrated attenuated iCCM effectiveness regardless of training quality. The study makes a substantial original contribution to implementation science in paediatric global health by generating a refined, empirically-tested programme theory for iCCM in post-conflict African settings. Keywords: iCCM, implementation science, realist evaluation, Adamawa State, North East Nigeria.