Extreme Risk Protection Order laws and fatal violence against women: a quasi-experimental study.

BACKGROUND: Rates of intimate partner homicides of women in the USA are high relative to other high-income countries, especially those involving firearms. We evaluated one potential policy solution by examining state Extreme Risk Protection Order (ERPO) firearm transfer laws and intimate partner homicide of women. METHODS: The primary outcome was state rates of intimate partner homicide deaths among females aged 10-64 years per 100 000 using data from the Supplementary Homicide Reports (2014-2022). We also examined firearm homicide rates using vital statistics data (2014-2023), overall and stratified by racialised groups. This study used a two-stage least-squares instrumental variable approach where our exposure was the annual count of ERPO petitions filed in each state per 100 000 population and our instrument was the presence of an ERPO policy. RESULTS: Overall, we did not observe statistically significant reductions in state rates of intimate partner homicides (beta=-0.05 per 100 000; 95% CI -0.11 to 0.01) or firearm homicides among women (beta=-0.04 per 100 000; 95% CI -0.13 to 0.05) associated with ERPO implementation. However, among white women, each annual increase of 1 per 100 000 in the rate of ERPO petition filings was associated with a statistically significant decrease in the rate of firearm homicides of -0.04 per 100 000 (95% CI -0.08 to -0.01, p=0.022). CONCLUSIONS: Our findings suggest the potential for ERPO use to prevent fatal violence against white women and underscore the need for equitable policy solutions for black and Indigenous women who face the highest rates of intimate partner violence.