The role of water and sanitation, diarrheal infection, and breastfeeding on child stunting: insights from a historical analysis of the Cebu longitudinal health and nutrition survey, 1984–1986

Background: The association between improved water and sanitation (WATSAN) and child nutritional status may operate through diverse pathways and interact with other risk factors. We examined the joint association between WATSAN and child stunting in the Philippines during a historically critical period marked with substantial heterogeneity in WATSAN conditions. Methods: Data came from the Cebu Longitudinal Health and Nutrition Survey. Birth surveys and bi-monthly follow-up surveys from 1984–1986 were used for the final analytic sample of 2,584 children. We ran a series of logistic regression models for WATSAN and child stunting at age 2, before and after adjusting for a priori selected covariates. We performed stratified analysis by the child's experience of diarrhea in the first 2 years (never vs. at least 1 incidence), and tested for interaction with breastfeeding practices in the first 6 months (never vs. partial vs. predominant). Results: 53.9% of our sample were stunted at age of 2 and only 26.8% had access to improved WATSAN. In our final multivariate adjusted model, improved WATSAN was associated with a significantly reduced odds of stunting (odds ratio [OR], 0.59; P < 0.01). This was consistently found among children who have never experienced diarrheal incidence (OR, 0.38; P = 0.03) as well as those who have experienced diarrhea at least once (OR, 0.62; P < 0.05). A marginally significant interaction was found between WATSAN and breastfeeding (P = 0.10). Conclusion: Ensuring access to improved WATSAN has great potentials to reduce child stunting, and this could occur through diverse pathways that do not necessarily involve clinically detectable signs of infection. Improved WATSAN appears to be relatively more important for children who are not breastfed. Future studies should explore these associations using more recent data and in the context of other lowand middle-income countries.