Community Improved Sanitation Coverage and Childhood Stunting (SAR23) - Analysis Brief [AB31]

In 2020, an estimated 1.1 billion people had no access to an improved sanitation facility. Although a person's access to improved household sanitation facilities can prevent exposure to fecal contamination in a person's household, there is growing awareness that the shared community environment can be contaminated when other households lack access to improved sanitation facilities. This analysis includes data from the 2018 DHS surveys for Nigeria and Zambia. Both countries have poor sanitation outcomes, with slightly more than half of the population having access to an improved sanitation facility. Additionally, both countries show geographic variation in access to improved sanitation, with access ranging from 17% in Ebonyi State to 93% in Abia State in Nigeria, and from 6% in the Western Province of Zambia to 80% in Lusaka Province. Stunting is also high in both countries, with 37% of children under age 5 in Nigeria and 35% of children in Zambia being stunted. The analysis used a geospatial modeling approach to create maps of the population with access to improved sanitation estimated down to 5 x 5 kilometer areas. Multilevel logistic regression was conducted to explore the relationship between community improved sanitation coverage and stunting among children. The analysis controlled for background characteristics such as age and sex of the child, mother's height, household wealth, household crowding, urban/rural residence, and improved source of drinking water. The analysis also controlled for geospatial covariates including region, nighttime light levels, and travel time to a high-density urban center. The results of the analysis showed that improved sanitation at the community level is associated with reduced odds of childhood stunting in Nigeria overall. For every 10% increase in community-level improved sanitation coverage, the odds of stunting decrease by 3%. However, access to improved sanitation at the household level is not associated with reduced odds of childhood stunting in Nigeria. Community-level improved sanitation coverage is also associated with reduced odds of childhood stunting in North West and South West zones in Nigeria. In Zambia, neither community-level improved sanitation coverage nor household-level improved sanitation is associated with reduced odds of childhood stunting at the national or provincial levels. The results of this analysis are mixed, with community-level improved sanitation coverage being a more important predictor of stunting than household access to improved sanitation in Nigeria. The lack of an association between community-level improved sanitation and stunting in Zambia is not particularly unusual, as the existing body of literature on this topic is mixed as well. Nonetheless, community-level improved sanitation coverage should be considered when evaluating sanitation-related health outcomes.