Dietary and environmental mediators of socioeconomic inequalities in child undernutrition in West Africa

Background and objectives: A number of studies have investigated the association of socioeconomic status (SES) with child undernutrition in several regions including West Africa. However, to date no study has attempted to elaborate the possible pathways through which socioeconomic disadvantage leads to higher prevalence of child undernutrition. Document the level and trend of low birth weight (LBW), and child undernutrition in West Africa, and further establish the mediating role of dietary factors and household environmental quality in the association of SES with child undernutrition. Methods: We analyze DHS and World Bank data for the period 1985 – 2019. Random effects model with Knapp–Hartung adjustment to the standard error (SE) was used to derive overall prevalence estimates. Fixed-effect OLS regression with cluster robust SE was used to conduct time trends analyses. 132,448 under-five children born within five years preceding the survey were investigated. Poisson regression with robust SE was used to estimate prevalence ratios and their corresponding 95% CI. Structural Equation Modelling was used to conduct the mediation analysis. Results: We observed a decline in prevalence of stunting (β=0.20%; 95%CI: -0.43%, 0.03%), log-wasting (β=-0.02%; 95%CI: 0.02%, -0.01%), log-underweight (β=-0.02%; 95%CI: -0.03%, 0.01%) and anemia (β=-0.44; 95%CI: -0.55%, -0.34%), and an increase in LBW (β=0.06%; 95% CI: -0.10%, 0.22%) in West Africa over the period. Pooled prevalence of stunting, wasting, underweight, anemia and LBW in WA for the period 1985-2019 was 26.1%, 16.4%, 22.7%, 76.2% and 11.3%, respectively. Minimum dietary diversity (MDD), minimum meal frequency (MMF), minimum acceptable diet (MAD), and HEQ mediated the association of low maternal education and poor household wealth with child undernutrition. Percentage mediation ranged from 20.3% to 26.6% for MDD, 6.4% to 14.2% for MMF, 24.2% to 33.5% for MAD, and 6.6% to 7.3% for HEQ. Conclusions: We provide the evidence base for assessing the effectiveness of national and regional interventions that have been implemented over the last four decades for tackling child undernutrition and LBW in West Africa. Evaluating existing interventions for effectiveness should be done through a socioeconomic lens if we are to address the high burden of child undernutrition in West Africa.