Assessing the correlates of wasting among children under five and their mothers in the Bay and Hiran regions of Somalia.

Background: To address Somalia's high wasting burden, it is imperative to understand the country's context-specific correlates of wasting. We aimed to assess the correlates of wasting among children under five (CU5) and mothers in Bay and Hiran. Methods: We analysed midline (CU5 n = 956; mothers n = 1066) and endline (CU5 n = 833; mothers n = 1023) data from a randomised controlled trial. We explored child (weight-for-height z-scores (WHZ)) and maternal outcomes (mid-upper arm circumferences) via linear regression for children and via Poisson regression for children and mothers, implementing a backwards elimination approach in a hierarchical way. We stratified CU5 models by region and age. Results: CU5 wasting was 12.9% at midline and 14.4% at endline, with a higher burden in Hiran. At midline, maternal underweight and maternal open defecation adversely affected WHZ, while having >1 CU5 was protective. At endline, no maternal education, a high reduced coping strategy index, and not consuming animal-based protein were associated with lower WHZ, while maternal overweight was protective. Stratifying by age did not reveal additional correlates. The following additional correlates appeared when stratifying by region: child illness, household decision-making, and household head gender in Bay and household open defecation and non-food item kits in Hiran. Mothers' wasting was 8% at midline and 12% at endline, with the following identified correlates: an unacceptable food consumption score, moderate-to-severe household hunger, and poor child stool disposal practices at midline and household open defecation at endline. Maternal decision-making was protective at midline. Conclusions: Our results highlight variation in the key correlates of wasting by region, season, and age and contribute to evidence on the multifactorial correlates of wasting, encouraging context-specific approaches addressing the immediate, underlying, and basic causes of malnutrition. The findings emphasise the importance of maternal nutrition for child nutrition and the need for interventions considering household food security, sanitation, and gender dynamics in this humanitarian setting. Registration: The cluster-RCT is registered at ClinicalTrials.gov (ID: NCT06642012).