A systematic review of studies comparing myocardial infarction mortality for generalists and specialists: lessons for research and health policy.

BACKGROUND: Much of the research comparing specialists and generalists is from studies of patients who had a myocardial infarction. The present study systematically examined this research.
METHODS: Medline was used to search for all articles published from 1990 to 2003 that compared cardiologists and generalists for adjusted mortality rates of patients with myocardial infarction. From each article identified, information was abstracted on factors that could have influenced the comparisons.
RESULTS: The studies consistently found that patients of generalists were at greater risk of mortality from both cardiac and noncardiac risk factors and had higher unadjusted mortality rates. Adjusting for risk factors decreased the differences between cardiologists and generalists. Studies that seemed to do the best job taking into account patient differences had similar adjusted-mortality rates for the cardiologists and generalists. No studies adequately took into account reasons the patient did not have care by a cardiologist, eg, patient preferences, severity of comorbid disease, general health status, or resource availability.
CONCLUSIONS: Generalists and cardiologists differ substantially with respect to their patients and practice environments. Results comparing patient outcomes by specialty are often influenced by important patient or resource characteristics that were not taken into account.