Is the Affordable Care Act Medicaid expansion in the USA associated with reductions in intimate partner violence victimisation?

Objective: Intimate partner violence (IPV) affects an estimated 47% of women living in the USA in their lifetime and is associated with increased risk of physical and mental health concerns. Current prevention efforts focus on individual and family-level interventions rather than macrosystem-level policies. Thus, we sought to test the effects of Medicaid expansion on the rates of IPV and violence more broadly.

Methods: Present analyses use retrospective longitudinal data from the National Crime Victimization Survey (NCVS). State level rates of total violence and IPV were measured per 1000 population from the NCVS for years 2008-2018 as 3-year averages for each state. A two-way fixed-effects difference-in-differences model was fit to evaluate differences in the change in violence outcomes pre-2014/post-2014 in Medicaid expansion states versus non-expansion states.

Results: Comparison states had a significantly higher proportion of residents who were black, living below the federal poverty level and with lower educational attainment. Before Medicaid expansion, comparison states had a significantly lower mean rate of total violence and IPV per 1000 population. In two-way fixed effects difference-in-differences models, there was no statistically significant association between Medicaid expansion and IPV or total violence.

Discussion: Despite null findings, our study adds to the evidence base evaluating the impacts of macro-level policies on different forms of violence. The pathways by which Medicaid expansion could contribute to violence reduction are multifaceted with numerous mediators and those pathways may not be sufficiently strong to generate impacts. Additional work is warranted to further probe Medicaid expansion's impact on violence prevention.