A Systematic Review and Meta-Analysis of Bystander Intervention Programs for Intimate Partner Violence and Sexual Assault

Abstract

Objective: A situational model of bystander behavior (SMBB) can explain the steps that a bystander takes when intervening in a situation of intimate partner violence (IPV) and sexual assaults-awareness, definition, responsibility, bystander efficacy, and action to intervene. The present study examined the effectiveness of existing bystander intervention programs based on the steps of the SMBB. Method: Overall, 136 separated measured outcomes from 33 studies were systematically searched. The separated outcomes were allocated into five domains based on the SMBB and three more domains for those outcomes that could not be allocated based on the model: (a) awareness, (b) definition, (c) empathy for victims, (d) responsibility, (e) bystander efficacy, (f) gender norms/attitudes, (g) intention to intervene, and (h) action to intervene. They were analyzed through meta-analysis. Results: The bystander intervention programs were effective with a small-to-medium effect size (ES). The programs significantly affected seven out of eight outcome domains. Among the domains, definition was improved the most, followed by intention to intervene, bystander efficacy, responsibility, action to intervene, awareness, and gender norms/attitudes. The programs targeting both genders showed higher impact than those targeting either males or females. Adults were affected more than did adolescents by the programs. Traditional offline methods, virtual reality, and web-based methods significantly improved the outcomes, while videos did not. Conclusions: Our findings are beneficial for specifying and expanding the SMBB to develop detailed bystander interventions. Political efforts to enact laws against IPV and sexual assaults are essential.