Racial differences in the association of county-level contextual factors and avoidable deaths from cardiovascular disease

Avoidable deaths from cardiovascular disease are those that can be prevented through behavioral changes or access to quality medical care. This study examines the association of county health factors with avoidable cardiovascular death rates among non-Hispanic blacks and whites. Avoidable deaths were defined as deaths resulting from an underlying cause of heart disease, stroke, or hypertensive disease in decedents aged <75 years. National Vital Statistics System mortality data were used to calculate age-adjusted, county-specific, race-stratified avoidable death rates for years 2006-2010 combined. Spatially smoothed rates were merged with County Health Rankings health factor data, which includes state-specific county rankings for social-economic environment, health behaviors, clinical care, and physical environment. Using Poisson regression models, and controlling for state variation using America’s Health Rankings data, we calculated rate ratios (RR) comparing counties in the lowest (worst) to highest (best) quartile for each health factor. Maps revealed that counties with the highest avoidable death rates were found primarily throughout the South census region. Among blacks, avoidable death RRs (95% CI) comparing counties ranked worst to best were 1.07 (1.04, 1.11) for health behaviors, 1.12 (1.09, 1.16) for clinical care, 0.99 (0.96, 1.02) for physical environment, and 1.30 (1.25, 1.34) for social-economic environment. Among whites, RRs (95% CI) comparing counties ranked worst to best were 1.19 (1.16, 1.22) for health behaviors, 1.23 (1.20, 1.25) for clinical care, 1.09 (1.06, 1.11) for physical environment, and 1.16 (1.14, 1.19) for social-economic environment. Among blacks, low social-economic rankings were most strongly associated with higher avoidable death rates. Among whites, clinical care rankings exhibited the strongest association.  County contextual factors may impact race groups differently and should be considered for public health planning.