The use of behavioural-science informed interventions to promote latrine use in rural India: a synthesis of findings

Abstract

In 2014, the Indian government launched the Swachh Bharat Mission (SBM) to end open defecation, a historically common practice that has persisted in the country despite household latrine ownership. The majority of SBM resources targeted latrine construction; however, enabling access to sanitation but not guaranteeing use. In 2016, the International Initiative for Impact Evaluation (3ie) funded four cluster-randomized trials to assess the impact of interventions designed to increase latrine use by targeting the behavioral barriers to and facilitators of latrine use among those with household latrines in rural Bihar, Karnataka, Odisha, and Gujarat. The aim of this meta-synthesis is to estimate the combined effects of these behavioural-science informed interventions on latrine use in rural India.The four trials were conducted by Oxford Policy Management, Swiss Federal Institute of Aquatic Science and Technology (EWAG), Emory University, and the London School of Hygiene and Tropical Medicine. All four trials used an agreed upon set of measures to assess self-reported latrine use, the primary outcome, and a household-level latrine observation index. The use of similar measurements enables comparison. For each study, we calculate an intervention treatment effect through difference-in-differences estimates, which then enables us to calculate the average treatment effect across studies through a difference-in-difference meta-analysis using the individual-participant data.Self-reported latrine use increased in most states over the course of the intervention (βBihar=0.99[0.57,1.40], βKarnataka=1.24[0.51,1.97], βOdisha=0.65[0.51,0.80], βaverage effect=0.66[0.23,1.09], βGujarat=-0.41[-0.93,0.12]). The increase tended to be larger in intervention than control villages (βGujarat=0.90[0.12,1.69]], βKarnataka=1.05[0.04,0.36], βOdisha=0.42[0.19,0.66], βaverage effect=0.51[0.26,0.76], βBihar=-0.25[-0.72,0.86]). However, there was no difference in the change in the latrine observation index between intervention and control villages (βBihar=-0.06[-0.19,0.07], βKarnataka=0.09[-0.17,0.34], βOdisha=-0.5[0.15,0.05], βGujarat=-0.03[-0.31,0.25] βaverage effect=0.02[-0.06,0.09]). We show that the four behavioural-science informed interventions increase self-reported latrine use among those with latrine access beyond increases presumably attributable to SBM alone. As SBM enters its next phase, focusing on the behavioural drivers of latrine use and non-use may help to maintain latrine use behaviors and change the behaviour of those who have yet to start using latrines.