Cluster-randomised controlled trials of individual and combined water, sanitation, hygiene and nutritional interventions in rural Bangladesh and Kenya: the WASH Benefits study design and rationale

Abstract

IntroductionEnteric infections are common during the first years of life in low-income countries and contribute to growth faltering with long-term impairment of health and development. Water quality, sanitation, handwashing and nutritional interventions can independently reduce enteric infections and growth faltering. There is little evidence that directly compares the effects of these individual and combined interventions on diarrhoea and growth when delivered to infants and young children. The objective of the WASH Benefits study is to help fill this knowledge gap.Methods and analysisWASH Benefits includes two cluster-randomised trials to assess improvements in water quality, sanitation, handwashing and child nutrition—alone and in combination—to rural households with pregnant women in Kenya and Bangladesh. Geographically matched clusters (groups of household compounds in Bangladesh and villages in Kenya) will be randomised to one of six intervention arms or control. Intervention arms include water quality, sanitation, handwashing, nutrition, combined water+sanitation+handwashing (WSH) and WSH+nutrition. The studies will enrol newborn children (N=5760 in Bangladesh and N=8000 in Kenya) and measure outcomes at 12 and 24 months after intervention delivery. Primary outcomes include child length-for-age Z-scores and caregiver-reported diarrhoea. Secondary outcomes include stunting prevalence, markers of environmental enteropathy and child development scores (verbal, motor and personal/social). We will estimate unadjusted and adjusted intention-to-treat effects using semiparametric estimators and permutation tests.Ethics and disseminationStudy protocols have been reviewed and approved by human subjects review boards at the University of California, Berkeley, Stanford University, the International Centre for Diarrheal Disease Research, Bangladesh, the Kenya Medical Research Institute, and Innovations for Poverty Action. Independent data safety monitoring boards in each country oversee the trials. This study is funded by a grant from the Bill & Melinda Gates Foundation to the University of California, Berkeley.RegistrationTrial registration identifiers (http://www.clinicaltrials.gov): NCT01590095 (Bangladesh), NCT01704105 (Kenya).

The Role of Adherence on the Impact of a School-Based Water, Sanitation, and Hygiene Intervention in Mali

“…This points to the importance of interventions that address multiple routes of transmission (i.e., WASH), an issue that has been challenged in a review that found multiple interventions, were no more effective than single interventions in community settings, 20 and is subject to an ongoing multicenter study. 21 We report elsewhere on the positive impact of the intervention on reducing absence due to diarrhea and respiratory infection 9 ; as this was a secondary outcome of the study, we did not further explore this analysis.…”

Predictors of Drinking Water Boiling and Bottled Water Consumption in Rural China: A Hierarchical Modeling Approach

“…In addition to drinking water related covariates often controlled for in WaSH studies (e.g., household size and demographics, drinking water sources), we hypothesized that household income would be a key predictor of HWT use. 37,38 We were unable to estimate household income directly, and the governmentcollected income data we had were already aggregated at the village level. We therefore used several proxies for household income and wealth (e.g., per capita TV ownership) as well as proxies for access to services (e.g., time needed to reach the nearest health clinic).…”

Pilot Cluster Randomized Controlled Trials to Evaluate Adoption of Water, Sanitation, and Hygiene Interventions and Their Combination in Rural Western Kenya

“…The study's scientific objectives are to (1) determine if WASH interventions aid in early child development, (2) determine if the combination of WASH interventions is more beneficial than a single intervention alone, and (3) determine if the combination of WASH interventions plus nutrient supplements is more beneficial than any of the interventions or supplements alone. The complete main trial protocol along with its objectives and rationale have been published separately 5 ; the main study was registered at www.clinicaltrials.gov (NCT01590095 [Bangladesh] and NCT01704105 [Kenya]), and the pilot study was not separately registered. In preparation for the much larger randomized trial, the WASH Benefits project enrolled subjects in two separate but closely aligned pilot cluster, randomized trials of WASH interventions in rural western Kenya.…”