The effect of water and sanitation on child health: evidence from the demographic and health surveys 1986-2007.

BACKGROUND Despite continued national and international efforts, access to improved water and sanitation remains limited in many developing countries. The health consequences of lacking access to water and sanitation are severe, and particularly important for child development. METHODS To investigate the associations between child health and access to water and sanitation, we merged all available Demographic and Health Surveys (DHS) with complete birth histories and water and sanitation information. The merged data set of 171 surveys includes information on 1.1 million children under the age of 5 years in 70 low- and middle-income countries over the period 1986-2007. We used logistic models to estimate the effect of water and sanitation access on infant and child mortality, diarrhoea and stunting. RESULTS Access to improved sanitation was associated with lower mortality (OR = 0.77, 95% CI 0.68-0.86), a lower risk of child diarorhea (OR = 0.87, 95% CI 0.85-0.90) and a lower risk of mild or severe stunting (OR = 0.73, 95% CI 0.71-0.75). Access to improved water was associated with a lower risk of diarrhoea (OR = 0.91, 95% CI 0.88-0.94) and a lower risk of mild or severe stunting (OR = 0.92, 95% CI 0.89-0.94), but did not show any association with non-infant child mortality (OR = 0.97, 95% CI 0.88-1.04). CONCLUSIONS Although our point estimates indicate somewhat smaller protective effects than some of the estimates reported in the existing literature, the results presented in this article strongly underline the large health consequences of lacking access to water and sanitation for children aged <5 years in low- and middle-income countries.