Diffusion of an effective social and behavioral change intervention to prevent intimate partner violence and enhance gender-equitable norms in Nepal

Social norms approaches to intimate partner violence (IPV) prevention are a growing evidence-based practice, but assessment of impact diffusion beyond direct beneficiaries is especially rare. We examine the diffusion of an effective IPV prevention intervention beyond direct participants with 1181 married adult participants in Nepal’s Gandaki province. Study timepoints included pre-intervention, mid-intervention, post-intervention, and six months post-intervention. Cluster-adjusted regressions assessed change in IPV, social norms, and secondary outcomes for two intervention conditions (intervention participants; intervention community residents (community)) relative to adjacent control community residents. Intervention and community women's reported IPV decreased 26.8% and 20.5% respectively six-months post-intervention, with significant improvements in descriptive norms, gender equitable attitudes, relationship quality, and communication (for both intervention groups) and injunctive norms, leadership, and anti-violence advocacy (for intervention participants). Intervention and community men’s norms did not improve relative to control; however, both intervention groups reported improved anti-violence advocacy. Intervention men also improved in communication and help-providing to survivors. Change, an intervention intentionally designed for diffusion, may be effective at reducing IPV, improving associated norms, and extending programming benefits beyond those intentionally targeted.