Interplay among climate, WASH, and socioeconomic factors in child stunting in Bangladesh: a DHS-based analysis

Child undernutrition remains a public health challenge in Bangladesh. This study examined associations among household water, sanitation, and hygiene (WASH) conditions, climatic factors, socioeconomic characteristics, diarrhoeal disease, and child stunting. Pooled data from three rounds (2014, 2017, and 2022) of the Bangladesh Demographic and Health Survey (BDHS), comprising 18,919 children under 5 years of age, were analysed. Survey-weighted logistic regression and multilevel mixed-effects logistic regression models were used to examine factors associated with child stunting and diarrhoeal disease. Interaction effects between WASH conditions and climatic variables were assessed using predicted margins, while the Karlson–Holm–Breen method (KHB) was used to examine whether diarrhoeal disease mediated the association between WASH conditions and child stunting. 31.2% of children were stunted, while 5.2% experienced diarrhoea during the two weeks preceding the survey. After adjustment, WASH conditions were not independently associated with stunting or diarrhoeal disease. Household wealth, maternal education, and child age were the strongest factors associated with stunting. Interaction analyses indicated that associations between climatic factors and stunting varied across WASH conditions. These findings highlight the importance of socioeconomic conditions alongside climate adaptation and improved WASH services for addressing child stunting in Bangladesh.