Understanding the costs and cost-efficiencies of preventing stunting combining standard of care, nutrition supplementation and cash transfer interventions in Southern Angola: an analysis of implementation data from the MuCCUA cluster randomised trial

INTRODUCTION: To advance stunting reduction efforts, robust cost evidence on multisectoral interventions is essential for optimising resources and achieving outcomes efficiently. This study objective was to estimate the cost and cost-efficiency of three multisector interventions that combined standard of care (SOC), SOC plus cash transfers (SOC+CT) and SOC plus nutritional supplementation (SOC+NS) with small quantity lipid-based nutrient supplements (SQ-LNS) complemented with a family food ration (FFR) to prevent stunting in Southern Angola. Cost-effectiveness will be estimated in a future study. METHODS: Interventions were nested within the Mother and Child Chronic Undernutrition in Angola (MuCCUA) trial and costs estimated after 1 year of implementation. Using a mixed-methods approach, we estimated financial and economic costs from institutional and societal perspectives. Activity-based costing and the ingredients approach were used to capture and calculate total institutional costs and opportunity costs incurred by participants. Cost-efficiency of each intervention was calculated as cost per participant reached. Costs were adjusted for inflation and reported in 2024 USD. RESULTS: Through the first 12-month implementation period, MuCCUA interventions covered 1423 pregnant women and their children. Total institutional costs by intervention arms were: US$190 408 for SOC (n=463), US$414 946 for SOC+CT (n=479) and US$515 799 for SOC+NS (n=481). Total monthly costs per participant reached were US$12.85, US$27.07 and US$33.51, respectively, for SOC, SOC+CT and SOC+NS (societal costs: US$13.48, US$28.26, US$34.56). Personnel (73%) and staff training (24%) drove most costs in SOC, whereas supplies-cash transfers (32%) in SOC+CT and SQ-LNS with FFR (35%) in SOC+NS-were the largest expenses. CONCLUSION: Intervention costs were higher in the SOC+CT and SOC+NS arms driven by inputs and recurrent distributions of cash transfers and nutrition supplies and lower in the SOC driven by personnel and training. Cost-efficiency could be increased by increasing the implementation period, so that start-up costs are spread over a long period of time. Disaggregated costing enhances understanding of resource use in complex programmes, supporting operational planning and budgeting, and will inform forthcoming cost-effectiveness analyses once outcome data become available. TRIAL REGISTRATION NUMBER: NCT05571280.