Many studies have found that patients with acute myocardial infarction (AMI) who are admitted to hospitals with on-site revascularization facilities have higher rates of invasive cardiac procedures and better outcomes than patients in hospitals without such facilities. Whether such differences are due to invasive procedure rates alone or to other patient, physician, and hospital characteristics is unknown.
To determine whether invasive procedural rate variations alone account for outcome differences in patients with AMI admitted to hospitals with or without on-site revascularization facilities.
Retrospective, observational cohort study using linked population-based administrative data from a universal health insurance system.
One hundred ninety acute care hospitals in Ontario, 9 of which offered invasive procedures.
A total of 25 697 patients hospitalized with AMI between April 1, 1992, and December 31, 1993, of whom 2832 (11%) were in invasive hospitals.
Mortality, recurrent cardiac hospitalizations, and emergency department visits in the 5 years following the index admission, adjusted for patient age, sex, socioeconomic status, illness severity, and index revascularization procedures; attending physician specialty; and hospital volume, teaching status, and geographical proximity to invasive-procedure centers and compared by hospital type.
Patients admitted to invasive-procedure hospitals were much more likely to undergo revascularization (11.4% vs 3.2% at other hospitals; P