A comparison of cardiovascular procedure use between the United States and Canada

Objective. To compare the relative volume and intensity of all types of cardiovascular procedures, noninvasive tests, and diagnostic imaging for all elderly individuals between the United States and the three largest Canadian provinces (Ontario, Quebec, and British Columbia) by patient age. Data Sources. Service volume data for the United States for a one percent random sample of claims obtained from Medicare's National Claims History System. Data for Canada were obtained from the Ministries of Health in the three provinces representing 100 percent of the claims received by each Ministry. Study Design. Design is a cross-sectional analysis of 1992 claims data. Data Extraction Methods. The volume of cardiovascular services was measured in terms of the relative value units (RVUs) used in the Medicare fee schedule to calculate payments. Services were disaggregated into nine clinical categories, and comparisons were made by type of cardiovascular service and patient age. Results. Overall, cardiovascular procedure RVUs per elderly beneficiary are 53 percent greater in the United States than in Canada. Differences are largest for surgical procedures such as carotid thromboendarterectomy and revascularization procedures and smallest for diagnostic imaging and noninvasive tests. The differences between the countries in the use of cardiovascular procedures increase markedly with age. For example, the United States-to-Canada ratio for PTCA use is 1.87 for persons age 65 to 69, but 7.68 for persons age 80 and older. For CABG, the ratios are 1.36 and 7.16, respectively. Conclusions. Our findings suggest that global budgets in Canada result in lower levels of cardiovascular service use among the elderly, particularly among the very aged elderly. Patient age appears to play a much more important role in determining the recipients of cardiovascular procedures in Canada than in the United States. Whether these higher rates of procedure use among the very elderly in the United States compared to Canada reflect profligate service use or contribute to improved outcomes is uncertain.