Exploring the link between handwashing proxy measures and child diarrhea in 25 countries in sub-Saharan Africa: a cross-sectional study

Handwashing (HW) with soap is considered the most cost-effective intervention for reducing the risk of child diarrhea, but reliable measurement of HW behaviors is difficult. This study examined the association between proxy HW measures and child diarrhea by analyzing nationally representative household survey data from 25 countries in sub-Saharan Africa ( n = 212,492). The main explanatory variable was the HW ladder, representing a varying level of availability of HW materials in the household, and the outcome variable was a 2-week prevalence of child diarrhea. We estimated the prevalence ratio of child diarrhea between children with a basic HW station and without a HW place. Our analysis revealed that availability of water and soap at a HW place was associated with both increased and decreased prevalence ratios: 0.89 (95% CI 0.79–0.99) in Chad, 0.82 (0.69–0.97) in Mauritania, 1.30 (1.02–1.66) in Burkina Faso, and 1.67 (1.20–2.33) in Ghana. After controlling for country-fixed effects, the prevalence ratio was 0.95 (0.92–0.99), suggesting a protective effect of having a HW station with water and soap. Availability of HW resources is an important indicator to prevent child diarrhea, and HW promotion programs should be tailored to the unique context of each country.