Design and rationale of the Longitudinal Evaluation of Norms and Networks Study (LENNS): A cluster-randomized trial assessing the impact of a norms-centric intervention on exclusive toilet use and maintenance in peri-urban communities of Tamil Nadu

Ashraf, S.; Bicchieri, C.; Delea, M. G.; Das, U.; Chauhan, K.; Kuang, J.; Shpenev, A.; McNally, P. K.; Thulin, E.

Introduction: Inconsistent toilet usage is a continuing challenge in India. Despite the impact of social expectations on toilet usage, few programs and studies have developed theoretically grounded norms-centric behavior change interventions to increase toilet use in low-income settings. This protocol details the rationale and design of an ex-ante, parallel cluster-randomized trial evaluating the impact of a demand-side, norms-centric behavior change intervention on exclusive toilet use and maintenance in peri-urban Tamil Nadu, India. Methods and Analysis: Following two years of formative research, we developed an evidence-based norm-centric behavior change intervention called Nam Nalavazhvu (Tamil for 'Our wellbeing'). The multi-level intervention aims to shift collective beliefs by shifting empirical expectations or beliefs about other relevant people's sanitation practices. It also provides action-oriented information to aid individuals to set goals and overcome barriers to build, consistently use and maintain their toilets. This trial includes 76 wards in Pudukkottai and Karur districts, where half were randomly assigned to receive the intervention and the remaining serve as counterfactuals. During baseline and endline (conducted one year after the initiation of intervention) assessments, we collect relevant data and compare results between study arms to determine the impacts of the Nam Nalavazhvu intervention on sanitation-related behavioral, health, wellbeing outcomes and potential moderators. This study is powered to detect differences in the prevalence of exclusive toilet use between study arms. We will also conduct a process evaluation to understand the extent to which the intervention was implemented, as designed.