Methodological Challenges in Estimating the Impact of Improved Sanitation on Child Health Outcomes

This article aims to highlight the problems encountered in measuring the causal effect of sanitation on child health in observational studies. The focus is on the methodological issues related to sanitation indicators, health indicators, confounding bias, and selection bias, along with the controls arising in the process of assessing the impact of development efforts to imp­rove sanitation practices on health outcomes.

The impact of improved sanitation on child health has been assessed by various studies (Hammer and Spears 2016). Based on the approaches used in the estimation, the literature on the impact of imp­roved sanitation on health outcomes can be
divided into two strands: first, those studies that use randomised controlled experiments, and second, those that are based on observational data. The rando­mised experiments provide better estimates of causality by removing the biases originating from confounding. In this article, we summarise the findings of five important randomised controlled experiments; two conducted in Kenya and Bangladesh (published in 2018); two conducted in India (one each in Madhya Pradesh and Odisha) in 2014; and one in Mali in 2015. There is a consensus in the findings of these randomised experiments that des­pite a significant increase in toilet coverage and reduction in open defecation, the prevalence of diarrhoea (repor­ted for a period of one week) among children (less than five years) did not reduce, except in Bangladesh where diarrhoea reduction was modest (5.7% in controlled group and 3.5% in treated group) (Clasen et al 2014; Patil et al 2014; Pickering et al 2015; Null et al 2018; Luby et al 2018).