Validity of a common measure of intimate partner violence perpetration: Impact on study inference in trials in low- and middle-income countries.

Background: In lower-and middle-income countries (LMICs), studies of interventions to reduce intimate partner violence (IPV) perpetration are expanding yet measurement equivalence of the construct has not been established. We assessed the measurement equivalence of physical and sexual IPV perpetration used in recent trials in LMICs and tested the impact of non-invariance on trial inference. Methods: With data from three recent intervention trials among men (sample size 505-1537 across studies), we calculated tetrachoric correlations among items and used multiple-group confirmatory factor analysis to assess invariance across arms and over time. We also assessed treatment effects adjusting for covariate imbalance and using inverse probability to treatment weights to assess concordance of invariant measures with published results, where warranted. Findings: The average correlation among items was high and increased over time with several items in two studies showing correlations ≥0.85 at endline. Increases in correlation for physical IPV were concentrated in the treatment arm in two of the studies. The increase in correlation in sexual IPV differed by arm across studies. Across all studies, a correlated two-factor solution was the best fitting model according to the EFAs and CFAs. One study demonstrated measurement invariance across arms and over time. In two of the studies, longitudinal measurement non-invariance was detected in the intervention arms. In post hoc testing, one study attained invariance with a one-factor model and study inference was concordant with published findings. The other study did not attain even partial invariance. Conclusion: Common measures of physical and sexual IPV perpetration cannot be used for valid effect estimation without further refinement. The study highlights the need for an expanded item set, content validity assessments, further measurement invariance testing, and then consistent use of the item sets in future intervention trials to support accurate inference on the effectiveness of IPV perpetration prevention interventions.

Social norms, diffusion, and women's risk of intimate partner violence in Nepal: Impact assessment of a social and behavior Change communication intervention (Change Starts at home).

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.

Validity of a Common Measure of Intimate Partner Violence Perpetration: Impact on Study Inference in Trials in Low- and Middle-Income Countries.

Background: In lower-and middle-income countries (LMICs), studies of interventions to reduce intimate partner violence (IPV) perpetration are expanding, yet measurement equivalence of the IPV perpetration construct that is the primary outcome in these investigations has not been established. We assessed the measurement equivalence of physical and sexual IPV perpetration item sets used in recent trials in LMICs and tested the impact of non-invariance on trial inference. Methods: With data from three intervention trials among men (sample size 505-1537 across studies) completed in 2019, we calculated tetrachoric correlations among items and used multiple-group confirmatory factor analysis to assess invariance across arms and over time. We also assessed treatment effects adjusting for covariate imbalance and using inverse probability to treatment weights to assess concordance of invariant measures with published results, where warranted. Findings: The average correlation among items measuring IPV perpetration was high and increased by 0.03 to 0.15 for physical IPV and 0.07 to 0.17 for sexual IPV over time with several items in two studies showing correlations ≥ 0.85 at endline. Increases in the degree of correlation for physical IPV were concentrated in the treatment arm in two of the studies. The increase in correlation in sexual IPV differed by arm across studies. Across all studies, a correlated two-factor solution was the best fitting model according to the EFAs and CFAs. One study demonstrated measurement invariance across arms and over time. In two of the studies, longitudinal measurement non-invariance was detected in the intervention arms. In post hoc testing, one study attained invariance with a one-factor model and study inference was concordant with published findings. The other study did not attain even partial invariance. Conclusion: Common measures of physical and sexual IPV perpetration cannot be used validly for comparisons across treatment versus control groups over time without further refinement. The study highlights the need for an expanded item set, content validity assessments, further measurement invariance testing, and then consistent use of the item sets in future intervention trials to ensure valid inferences regarding the effectiveness of IPV perpetration prevention interventions within and across trials.