The effect of a large-scale water, sanitation, and hygiene intervention in Bangladesh on knowledge, behavior, and health: findings from an endline evaluation of a matched-pair cluster-controlled trial

Background: Diarrhea is a leading cause of child death in Bangladesh, where water quality, sanitation, and hygiene (WASH) technology and behavior uptake is low. From 2007 to 2012, the Sanitation, Hygiene Education, and Water Supply in Bangladesh Programme (SHEWA-B) aimed to improve WASH practices among 20 million rural residents through community hygiene promoters (CHPs). In 2010, the team implemented changes to improve the intervention, including simplifying messages and incentivizing CHP performance. This study evaluates the impact of SHEWA-B on knowledge, behavior, and childhood diarrhea outcomes after midline changes were applied.
Methods: This study included repeated cross-sectional surveys with embedded matched cohorts in intervention and control clusters. Cross-sectional surveys and structured observations at baseline, midline, and endline assessed the availability of WASH technology, caregiver knowledge, and behavior. Fieldworkers collected longitudinal monthly health data in a subset of control and intervention households to determine prevalence of diarrhea.
Results: Of 5091 households surveyed, participants residing in intervention clusters showed minimal improvements in knowledge, reported behavior, or use of WASH technology compared to the control clusters. Comparing endline to baseline, intervention clusters showed a greater increase in knowledge that washing hands before preparing food is important. Comparing endline to midline, intervention clusters showed a greater increase in use of improved latrines, but there were no differences in changes to any other indicators. During structured observations, intervention households improved more than control households at handwashing before preparing food and after cleaning a baby’s anus when comparing endline to baseline, but these changes were not seen when comparing endline to midline. Before midline changes were made, the prevalence of diarrhea among children remained similar in the intervention group (10.2%) and control group (10.0%). After midline changes were made, the prevalence continued to remain similar within each group (8.8% in intervention, 11.7% in control). The intervention clusters showed no improvement in diarrhea over time compared to the control.
Conclusion: SHEWA-B’s community-based WASH promotion did not yield the intended impact on knowledge, behavior, or health. This study shows that even after changes were implemented midway through the intervention, the intervention impact was limited. Greater priority should be given to approaches that have demonstrated effectiveness and more evaluations should be undertaken to improve large-scale programs.