Underuse of invasive procedures among Medicaid patients with acute myocardial infarction.

Objectives. The purpose of this study was to determine whether underuse of cardiac procedures among Medicaid patients with acute myocardial infarction is explained by or is independent of fundamental differences in age, race, or sex distribution; income; coexistent illness; or location of care. Methods. Administrative data from 226 hospitals in New York were examined for 11 579 individuals hospitalized with a primary diagnosis of acute myocardial infarction. Use of various cardiac procedures was compared among Medicaid patients and patients with other forms of insurance. Results. Medicaid patients were older, were more frequently African American and female, and had lower median household incomes. They also had a higher prevalence of hypertension, diabetes, lung disease, renal disease, and peripheral vascular disease. After adjustment for these and other factors, Medicaid patients were less likely to undergo cardiac catheterization, percutaneous transluminal coronary angioplasty, and any revascularization procedure. Conclusions. Factors other than age, race, sex, income, coexistent illness, and location of care account for lower use of invasive procedures among Medicaid patients. The influence of Medicaid insurance on medical practice and process of care deserves investigation.