PURPOSE: Wide geographic variations in cardiac rehabilitation (CR) participation in the United States have been demonstrated but are not well understood. Socioeconomic factors such as educational attainment are robust predictors of many health-related behaviors, including smoking, obesity, physical activity, substance abuse, and cardiovascular disease. We investigated potential associations between state-level differences in educational attainment, other socioeconomic factors, CR program availability, and variations in CR participation.
METHODS: A retrospective database analysis was conducted using data from the US Census Bureau, the Centers for Disease Control and Prevention, and the 1997 Medicare database. The outcome of interest was CR participation rates by state, and predictors included state-level high school (HS) graduation rates (in 2001 and 1970), median household income, smoking rates, density of CR program (programs per square mile and per state population), sex and race ratios, and median age.
RESULTS: The relationship between HS graduation rates and CR participation by state was significant for both 2001 and 1970 (r = 0.64 and 0.44, respectively, P < .01). Adding the density of CR programs (per population) and income contributed significantly with a cumulative r value of 0.74 and 0.71 for the models using 2001 and 1970, respectively (Ps < .01). The amount of variance accounted for by each of the 3 variables differed between the 2000 and 1970 graduation rates, but both models were unaltered by including additional variables.
CONCLUSIONS: State-level HS graduation rates, CR programs expressed as programs per population, and median income were strongly associated with geographic variations in CR participation rates.