RESUMO
Introduction: Intimate partner violence (IPV) is a significant public health, human rights, and development issue. While existing evidence posits that addressing social norms is key to IPV prevention, successful IPV interventions that include a norms approach are limited in number and methodological rigor and rarely include a formal investigation of the diffusion of intervention impact. We contribute novel findings to this intellectual and programmatic space with evidence on a social and behavior change communication (SBCC) intervention (Change Starts at Home) in Nepal designed to prevent IPV and shift social norms towards greater gender equity. Methods: Participants included 442 married women across 13 communities assessed at three timepoints: before intervention (baseline), at the completion of the core couple's curriculum and edutainment (midline), and at the conclusion of the diffusion curriculum (endline). Generalized estimating equations with propensity-score adjustments were used to determine change in outcomes at midline and endline for two intervention conditions (direct beneficiary, N = 173; and resident of the intervention community, (N = 178) relative to control (N = 91). Results: IPV victimization significantly decreased in both intervention conditions at midline, with larger reductions in direct beneficiaries. At endline, direct beneficiaries had sustained reduction in IPV relative to control participants. Positive injunctive norms also significantly improved by midline for both intervention groups, whereas improvements in descriptive norms for intervention groups were matched by improvements in the control group at both midline and endline. Several secondary outcomes showed significant improvements for both intervention groups at midline and/or endline, including in-law violence, financial decision-making, communication, and relationship quality, with additional improvements for the direct beneficiaries in attitudes, leadership, GBV advocacy, and diffusion. Conclusion: This study sheds light on the effectiveness of the Change intervention, the role of addressing social norms in IPV prevention efforts, and the benefits of organized diffusion.