Social Vulnerability and Childhood Health: Bayesian Spatial Models to Assess Risks from Multiple Stressors on Childhood Diarrhoea in Malawi

Childhood diarrhoea accounts for over 15% of all under-five deaths in Africa. The disease is exacerbated by social vulnerability. This study operationalizes social vulnerability by using three indicators: water poverty, sanitation and assets, to capture social disadvantage, which measures individual or community resources to prevent or mitigate health effects. We particularly investigated the relationship between childhood diarrhoea and risks emanating from multiple stressors: water poverty, poor sanitation and low wealth status, which define social vulnerability. Using data from the 2013/14 Malawi MDG Endline Survey (MMES), we fitted spatial models assuming that the combined effect of social vulnerability indicators, together with individual covariates, exhibit spatial correlation and heterogeneity on the outcome-diarrhoea status. Findings showed evidence of spatially varying risk imposed by social vulnerability indicators on childhood diarrhoea. We established a positive relationship between diarrhoea and water poverty, and negative association with poor sanitation and low wealth status. Spatial characterization of health effects of social vulnerability presents an important step towards targeted interventions in diarrhoea management. Our use of district level mapping provides for optimal planning and implementation, particularly, for the lowly placed individuals who are geographically located in high risk areas, since most decentralized decision making processes are made at this level.