Evaluating the Role of Sanitation in Improving Child Health and Nutrition: Does it Matter and Can We Make it Count?
Sumeet Rajshekhar Patil
Doctor of Philosophy in Epidemiology
University of California, Berkeley
Professor John M. Colford, Jr., Chair
Poor water, sanitation and hygiene (WASH) infrastructure and behaviors are believed to be the major contributors to the worldwide burden of diarrheal diseases and parasite infections; the second most leading cause of deaths among children under 5 years of age in developing and under-developed countries. India alone accounts for a third of those without improved sanitation (814 million), nearly 60% of those who practice open defecation (626 million), 25% of the world’s deaths from diarrheal diseases among children under 5 years of age and approximately one third of the stunted children globally. Compared to this staggering burden of poor WASH in India, research on which WASH interventions are efficacious is limited particularly on sanitation.
This dissertation seeks to bridge some of the gaps in sanitation public health research by answering following three questions.
Does India’s Total Sanitation Campaign (TSC) – one of the largest rural sanitation program in the world – deliver the hypothesized health benefits of improved sanitation to pre-school age children in India? I use a cluster randomized controlled trial to evaluate the effectiveness of the TSC in terms of prevalence of diarrhea, highly credible gastrointestinal infections, parasitic infections, anemia and child growth in terms of age adjusted height, weight and arm circumference. The sample consists of 5239 children under the age of 5 years from 80 villages in Dhar and Kargone districts of Madhya Pradesh state. I find that while the TSC almost doubled the coverage of private toilets (41% in the intervention group vs. 19% in the control group), the relative reduction in the open defecation rate was small and remained high in absolute magnitude (73% in the intervention group vs. 83% in the control group). Possibly due to inadequate reduction in open defecation levels, the TSC did not improve health of children under the age of 5 years in terms of above health outcome indicators.
Can the private toilet coverage increase substantially by reducing the price of the toilets through subsidies? Subsidies are a cornerstone of India’s TSC to increase private toilet coverage however little is known whether and to what extend these subsidies can increase the toilet coverage. I estimate the arc price elasticity of demand for private toilets using the data from the TSC trial in Madhya Pradesh. Taking advantage of variation in the level of subsidies offered by the Government of Madhya Pradesh to build private toilets, I find that the price elasticity of toilet demand is 0.91 so that if the price of a private toilet is reduced from ₹18000 to ₹6000 as per the new sanitation program norms in India, the private toilet coverage in rural India can increase from 30% (as per Census 2011 data) to 80%. However, using data from another experimental efficacy trial in Odisha of a pilot sanitation program that consisted of intensive behavior change, I find that the price elasticity is 0.26 and statistically not different from 0. The findings provide an evidence that the demand for private toilets is inelastic and reducing the price of toilets through subsidies may not be enough to increase the toilet coverage. Whether the built toilets be used regularly resulting in drastic reductions in open defecation levels, and whether this reduction in open defecation will result in improved health outcomes for children still remain unanswered.
What are the importance of risk factors including owning a private toilet in explaining linear growth faltering among children aged 6-24 months? I propose and apply a variable importance analysis method using SuperLearner –– a machine learning based ensemble algorithm –– to objectively and non-parametrically model the relationship between HAZ and 51 risk factors related to child nutrition, pre- and post-natal care, mothers’ health and nutrition, household socioeconomics, and water and sanitation. I also apply a new estimator called Targeted Maximum Likelihood Estimator to estimate the magnitude and standard error of variable importance measures.
I apply the proposed method the nationally representative Demographic and Health Survey data from India as a case study application. Subject to the available data and model limitations, I find that the following are main risk factors for stunting: mother of short stature (< 145 centimeter height); child not fed as per the WHO recommended guidelines; boiling drinking water; and children second or later in the birth order. I find that access to private sanitation explained -0.09 Z loss in HAZ which is a much smaller importance than above variables. However, the importance of sanitation may be underestimated because access to private toilet is an underestimate or poor indicator of reduction in open defecation or the reduction in exposure to enteric pathogens in the community.
I conclude my dissertation by underlying the need for more evidence based advocacy, design and implementation of sanitation programs than what was done over the past 20 years, and flag some of the important consideration in design of future studies based on the insights gained in developing this dissertation.