Appropriateness of coronary angiography after myocardial infarction among Medicare beneficiaries: Managed care versus fee for service.

BACKGROUND: Previous studies have documented that cardiac procedures are performed less frequently in patients enrolled in managed-care plans than in those with fee-for-service coverage. However, it is not known whether this difference is due to less frequent use of cardiac procedures when they are indicated or to less frequent use when they are not indicated. METHODS: We compared the use of coronary angiography after acute myocardial infarction among Medicare beneficiaries who had traditional fee-for-service coverage with the use among Medicare beneficiaries enrolled in managed-care plans. The analysis was adjusted for differences in demographic and clinical characteristics of the patients and for characteristics of the hospitals to which they were admitted. We studied more than 50,000 beneficiaries in seven states and evaluated their care according to guidelines proposed by the American College of Cardiology and the American Heart Association (ACC-AHA). RESULTS: Among the 44 percent of patients in both groups who had ACC-AHA class I indications (those for which angiography is useful and effective), more fee-for-service beneficiaries than managed-care enrollees underwent angiography (46 percent vs. 37 percent, P