Effects of a large-scale participatory learning and action programme in women’s groups on health, nutrition, water, sanitation, and hygiene: a cluster-randomised controlled trial in Bihar, India

Evidence from small-scale randomised controlled trials suggests that interventions relying on community involvement through a participatory learning and action (PLA) approach can improve health outcomes in resource-poor settings. However, it is only poorly understood whether PLA-based interventions are effective after scale-up in a real-world setting. In a cluster-randomised controlled trial in Bihar, India, we assessed whether the PLA approach improved health, nutrition, water, sanitation, and hygiene (HNWASH) outcomes in adults and children when implemented state-wide by a government-supported agency. In the intervention, trained female facilitators ran 20 structured participatory meetings about key HNWASH topics in state-supported women’s groups. Unlike the strong results of small-scale trials, in the scaled-up government implemented intervention we do not observe systematic improvements in HNWASH knowledge, attitudes, practices or health outcomes. We discuss aspects of programme implementation that could explain these null effects. Our findings call for caution when promising public health interventions are transformed into large policy programmes.