State-level Clustering of Modifiable Risk Factors and Cardiovascular Mortality in the United States

Objectives: We investigated the state-level distribution of modifiable cardiovascular (CV) risk factors and their role in contributing to state disparities in CV mortality in the US.    

Methods: We constructed a CV risk index summarizing state-level exposure to seven major CV risk factors (current smoking, obesity, physical inactivity, alcohol abstinence, hypertension, elevated cholesterol, and diabetes) using the Behavioral Risk Factor Surveillance System. We mapped the distribution of the CV risk index across states. Linear regression was used to estimate associations between the CV risk index and state CV mortality. Models accounted for state-level race and income composition. A second set of models focused on stroke and non-stroke belt regions separately.     

Results: Risk factors were highly correlated at the state-level (Cronbach’s alpha=0.85 for men and 0.92 for women). The highest values of the CV risk index were concentrated in the southeastern states; the index was lowest in states in the north and west US. Each +1SD difference in the CV risk index was associated with higher CV mortality by 44.6 (95%CI 31.3-57.9) and 35.6 (95%CI 27.7-43.5) deaths per 100,000 for men and women, respectively. The index accounted for 11% (men) and 19% (women) of the variation in state-level CV mortality. The CV risk index was associated with comparable mortality differences within stroke belt and non-stroke belt regions, though the CV risk index explained a higher proportion of CV mortality variation in non-stroke compared to stroke belt region for men (24% versus 11%) and women (36% versus 4%).

Conclusions: Enhanced public health policies at the state-level designed to lower CV risk factors will likely reduce state-level disparities in CV mortality and yield further progress in reducing CV mortality nationally.