Hospital transfer of patients with acute myocardial infarction: the effects of age, race, and insurance type.

Background: Many factors precipitate the transfer of patients hospitalized for acute myocardial infarction, including clinical status and the need for diagnostic testing and therapeutic interventions not available at the admitting hospital. The objectives of this study were to assess the frequency of transfer to another hospital and to determine whether nonmedical factors, such as age, sex, race, and insurance status, are associated with transfer.
Methods: We conducted a prospective study of patients with acute myocardial infarction who were enrolled in the National Registry of Myocardial Infarction 2 from June 1994 through March 1998. The Registry involves 1674 hospitals in the United States. All patients survived to the time of hospital discharge or until transfer. Multivariable logistic regression models, with transfer as the outcome variable, were developed for the entire sample, as well as for subgroups determined by the interventional capabilities of the admitting hospital.
Results: Of 537,283 patients with acute myocardial infarction, 152,310 (28%) were transferred to another hospital after admission. After adjustment for differences in clinical and hospital characteristics, factors that were most associated with a reduced odds of transfer included older age (odds ratio [OR] = 0.43; 95% confidence interval [CI]: 0.42 to 0.44 for those aged >75 vs. <65 years), African-American race (OR = 0.69; 95% CI: 0.67 to 0.71 for African Americans vs. whites), and Medicaid/self-pay insurance status (OR = 0.68; 95% CI: 0.66 to 0.70 for Medicaid/self-pay vs. commercial insurance). These effects were most apparent for patients admitted to hospitals without full invasive diagnostic and therapeutic capabilities, but persisted to some extent among those admitted to hospitals with full invasive services.
Conclusion: Our findings suggest that nonmedical factors, including age, race, and insurance type, affect decisions regarding the transfer of patients hospitalized with acute myocardial infarction. As only a minority of the nation's hospitals offers a full range of cardiovascular diagnostic and therapeutic procedures, these findings reinforce ongoing concerns about disparities in access to health care services for some patients.