Objective. To examine the effects of market-level managed care activity on the treatment, cost, and outcomes of care for Medicare fee-for-service acute myocardial infarction (AMI) patients.
Data Sources/Study Setting. Patients from the Cooperative Cardiovascular Project (CCP), a sample of Medicare beneficiaries discharged from nonfederal acute-care hospitals with a primary discharge diagnosis of AMI from January 1994 to February 1996.
Study Design. We estimated models of patient treatment, costs, and outcomes using ordinary least squares and logistic regression. The independent variables of primary interest were market-area managed care penetration and competition. The models included controls for patient, hospital, and other market area characteristics.
Data Collection/Extraction Methods. We merged the CCP data with Medicare claims and other data sources. The study sample included CCP patients aged 65 and older who were admitted during 1994 and 1995 with a confirmed AMI to a nonrural hospital.
Principal Findings. Rates of revascularization and cardiac catheterization for Medicare fee-for-service patients with AMI are lower in high-HMO penetration markets than in low-penetration ones. Patients admitted in high-HMO-competition markets, in contrast, are more likely to receive cardiac catheterization for treatment of their AMI and had higher treatment costs than those admitted in low-competition markets.
Conclusions. The level of managed care activity in the health care market affects the process of care for Medicare fee-for-service AMI patients. Spillovers from managed care activity to patients with other types of insurance are more likely when managed care organizations have greater market power.