Variation in U.S. county-level cardiovascular disease death rates by measure of rural-urban status

This study examined variation in county-level cardiovascular disease (CVD) death rates among adults aged 35–64 years using four measures of rural-urban status: Urban Influence Codes, Rural-Urban Continuum Codes (RUCC), National Center for Health Statistics Urban-Rural Classification Scheme, and Core-Based Statistical Areas. We estimated 2021 CVD death rates and used Poisson regression models to calculate rate ratios (RR) for full and dichotomized rural-urban measures. All measures identified the largest RR in the middle of the rural-urban spectrum. RUCC demonstrated patterns by population size and adjacency. RR magnitude varied across dichotomization methods. These findings demonstrate complexity underlying rural-urban differences and can guide public health practice.