By: Sheela Sinharoy
The question, then, is whether improved sanitation infrastructure leads to improved nutrition. Several groups of researchers have been studying this in India, where 597 million people practice open defecation. Here at Emory, a group of researchers led by Dr. Thomas Clasen published a paper on their research last month in The Lancet. The study examines the effectiveness of a rural sanitation program on several outcomes, including child malnutrition.
Malnutrition was measured in two ways: through height-for-age z-score (HAZ) in children under two and weight-for-age z-score (WAZ) in children under five. HAZ is an indicator of chronic malnutrition, while WAZ is a measure of both chronic and acute malnutrition. The intervention had no effect on mean HAZ. Intention-to-treat analysis also showed no effect on mean WAZ, but per-protocol analysis showed a modest effect size of 0.10 (95% CI: 0.003-0.20). In other words, among the households that were compliant with the intervention, the children had slightly better WAZ scores. The lack of a stronger effect on child malnutrition was surprising enough to garner attention from The New York Times, which published an article titled, “Latrines May Not Improve Health of Poor Children”.
I wanted to learn more, and I was able to interview the lead author, Dr. Clasen. He explained that the intervention focused on latrine construction rather than latrine use, and, while it may seem counter-intuitive, some people prefer the culturally accepted practice of open defecation. In his words: “Coverage has to be almost exclusive. Use has to be almost exclusive.” Unfortunately, researchers do not have a good understanding of the factors that lead people to change their behavior and start using a latrine or how to incentivize this behavior.
Dr. Clasen further explained that his team’s findings are actually consistent with the findings of other studies in India. For example, Dr. Sumeet Patil and Dr. Benjamin Arnold have published separate studies, each of which similarly took place within the context of the Total Sanitation Campaign and, like Dr. Clasen’s study, found no effect on child nutrition. Both studies also found that many people continued to practice open defection despite having sanitation infrastructure.
A number of analyses are still underway, which the researchers hope will shed light on potential reasons for the lack of observed effects. For example, Dr. Clasen’s study found that “latrine use was nearly five times higher for women than for men or children.” It is not clear why men in particular had such low levels of compliance. Nor is it clear what role women play in the decision-making process around whether a household invests the resources necessary to build a latrine. If this decision is in the hands of men, and men are less likely to use a latrine, what are the implications for sanitation coverage and compliance?
The interest in this issue is such that UNICEF has recently held a three-day conference in New Delhi, India. The most recent national data show that almost 50% of children in India were chronically malnourished; identifying interventions to address this problem is therefore an urgent issue. Some researchers argue that one key to improving child nutrition in India lies in behavior change and achieving universal coverage and use of improved sanitation facilities
 Clasen T, Boisson S, Routray P, Torondel B, Bell M, Cumming O, et al. Effectiveness of a rural sanitation programme on diarrhea, soild-transmitted helminth infection, and child malnutrition in Odisha, India: a cluster-randomised trial. Lancet. 2014 [cited 2014 Nov 3]. doi: http://dx.doi.org/10.1016/S2214-209X(14)70307-9.
 UNICEF, WHO (2014) Joint Monitoring Programme for Water Supply and Sanitation. Progress on Drinking Water and Sanitation: 2014 Update. New York and Geneva: UNICEF and WHO.
 Patil SR, Arnold BF, Salvatore AL, Briceno B, Ganguly S, Colford JM, et al. The effect of India’s Total Sanitation Campaign on defecation behaviors and child health in rural Madhya Pradesh: a cluster-randomized controlled trial. PLOS Med. 11(8): e1001709. doi:10.1371/journal.pmed.1001709
 Arnold BF, Khush RS, Ramaswamy P, London AG, Rajkumar P, Ramaprabha P, et al. Causal inference methods to study nonrandomized, preexisting development interventions. Proc Natl Acad Sci USA. 2010 Dec 28;107(52):22605-10. doi: 10.1073/pnas.1008944107.
 India, Ministry of Health and Family Welfare. 2009. Nutrition in India: National Family Health Survey (NFHS-3) India, 2005–2006. Mumbai: International Institute for Population Sciences.