How do States’ Environmental Policy Contexts Predict Geographic Disparities in Cardiovascular Disease Mortality?

While cardiovascular disease (CVD) mortality rates have been declining in most U.S. counties, significant geographic disparities have persisted over time. The polarization of U.S. state policies, particularly in environmental regulations, may play a crucial role in shaping geographic disparities in CVD mortality. Using data from multiple sources and multilevel mixed-effect linear regression models, I examined the associations between states’ environmental policy contexts (using an index of eight policies) and county-level CVD mortality rates for the years 2000–2014 and how these associations vary by counties’ sociodemographic composition, including race/ethnicity, personal income, and unemployment rate. I found significant relationships between states’ current environmental policy contexts and CVD mortality rates. More liberal state policy scores on the environment were associated with lower county-level CVD mortality rates, net of covariates. However, this association was stronger among counties with larger shares of non-Hispanic Black and low-income residents. Consequently, disparities in CVD mortality across counties of different racial/ethnic and income composition were largest in states with conservative environmental policy scores and smallest in states with liberal environmental policy scores. These findings underscore the significance of states’ environmental policy contexts in predicting CVD mortality rates and shed light on the population heterogeneity in the association between states’ environmental policy contexts and CVD mortality. The findings also highlight the potentially important role of environmental policies in shaping health disparities and the joint effects of policies and local contexts on population health.