Norms and Social Network-Centric Behavior Change Intervention (Nam Nalavazhvu) for Improved Toilet Usage in Peri-Urban Communities of Tamil Nadu: Protocol for a Cluster-Randomized Controlled Trial.

Background: 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 norm-centric behavior change interventions to increase toilet use in low-income settings.

Objective: The objective of this paper is to detail the rationale and design of an ex ante, parallel cluster-randomized trial evaluating the impact of a demand-side, norm-centric behavior change intervention on exclusive toilet use and maintenance in peri-urban Tamil Nadu, India.

Methods: Following formative research, we developed an evidence-based norm-centric behavior change intervention called Nam Nalavazhvu (Tamil for "our well-being"). The multilevel intervention aims to improve toilet usage 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 own, consistently use, and maintain their toilets. This trial includes 76 wards in the Pudukkottai and Karur districts, where half were randomly assigned to receive the intervention and the remaining served as counterfactuals.

Results: We enrolled wards and conducted a baseline survey among randomly selected individuals in all 76 wards. The 1-year behavior change intervention is currently ongoing. At the endline, we will collect relevant data and compare results between study arms to determine the impacts of the Nam Nalavazhvu intervention on sanitation-related behavioral, health, and well-being outcomes and potential moderators. This study is powered to detect differences in the prevalence of exclusive toilet use between study arms. We are also conducting a process evaluation to understand the extent to which the intervention was implemented as designed, given the special pandemic context.

Conclusions: Findings from this trial will inform norm-centric behavior change strategies to improve exclusive toilet usage.

Trial Registration: ClinicalTrials.gov NCT04269824; https://www.clinicaltrials.gov/ct2/show/NCT04269824.

International Registered Report Identifier (irrid): DERR1-10.2196/24407.