Implementation Science Framework for Scaling Up Childhood Blindness Prevention in Northern Nigeria

Childhood blindness prevention programmes in northern Nigeria have demonstrated efficacy in controlled project environments but consistently fail to achieve scale due to implementation barriers that are poorly theorised and inadequately addressed. This study develops and applies an implementation science framework to guide the scale-up of childhood blindness prevention in northern Nigeria. A three-phase implementation science study will be conducted using the Consolidated Framework for Implementation Research (CFIR) and the Expert Recommendations for Implementing Change (ERIC) compilation. Phase one applies CFIR to conduct implementation barrier and facilitator assessments in 30 health facilities implementing childhood blindness prevention activities across Kano, Sokoto, Zamfara, and Kebbi States, combining document review, observation, and qualitative interviews. Phase two uses intervention mapping to develop a scale-up strategy drawing on identified facilitators and targeting specific barriers. Phase three pilots and evaluates the scale-up strategy in a cluster of 15 health facilities, assessing fidelity, reach, adoption, and programme outcome indicators including proportion of premature neonates screened for ROP, vitamin A supplementation coverage, and childhood cataract case detection rate. Northern Nigeria accounts for the majority of Nigeria's childhood blindness burden but receives disproportionately less programme investment relative to population size and disease burden. Implementation science perspectives have been rarely applied to ophthalmic programme scale-up in Africa, representing a theoretical and methodological gap this study fills. Findings will generate an original implementation framework and practical scale-up toolkit for adoption by the Federal Ministry of Health. Keywords: implementation science, childhood blindness, scale-up, northern Nigeria, CFIR framework