Use of cardiac rehabilitation by medicare beneficiaries after myocardial infarction or coronary bypass surgery

Background - Cardiac rehabilitation ( CR) is effective in prolonging survival and reducing disability in patients with coronary heart disease. However, national use patterns and predictors of CR use have not been evaluated thoroughly. Methods and Results - Using Medicare claims, we analyzed outpatient ( phase II) CR use after hospitalizations for acute myocardial infarctions or coronary artery bypass graft surgery in 267 427 fee-for-service beneficiaries aged >= 65 years who survived for at least 30 days after hospital discharge. We used multivariable analyses to identify predictors of CR use and to quantify geographic variations in its use. We obtained unadjusted, adjusted- smoothed, and standardized rates of CR use by state. Overall, CR was used in 13.9% of patients hospitalized for acute myocardial infarction and 31.0% of patients who underwent coronary artery bypass graft surgery. Older individuals, women, nonwhites, and patients with comorbidities ( including congestive heart failure, previous stroke, diabetes mellitus, or cancer) were significantly less likely to receive CR. Coronary artery bypass graft surgery during the index hospitalization, higher median household income, higher level of education, and shorter distance to the nearest CR facility were important predictors of higher CR use. Adjusted CR use varied 9- fold among states, ranging from 6.6% in Idaho to 53.5% in Nebraska. The highest CR use rates were clustered in the north central states of the United States. Conclusions - CR use is relatively low among Medicare beneficiaries despite convincing evidence of its benefits and recommendations for its use by professional organizations. Use is higher after coronary artery bypass graft surgery than with acute myocardial infarctions not treated with revascularization procedures and varies dramatically by state and region of the United States.