Purpose: Previous studies have found that teaching hospitals produce better acute myocardial infarction (AMI) outcomes than nonteaching hospitals. However, these analyses generally excluded patients transferred out of nonteaching hospitals and did not study outcomes by patient risk level. The objective of this study was to determine whether admission to a teaching hospital was associated with greater survival after accounting for patient transfers and patient severity.
Method: This observational study used logistic models to examine the association between hospital teaching status and 30-day mortality of AMI patients, adjusting for patient comorbidities and common time trends. The sample included 1,309,554 Medicare patients admitted from 1996 to 2004 to 3,761 acute care hospitals for AMI. The primary outcome was 30-day all-cause, all-location mortality.
Results: Mortality was slightly lower in minor teaching hospitals compared with nonteaching hospitals (odds ratio [OR] 0.97; 95% confidence interval [CI] 0.95-0.99) but not different between major teaching and nonteaching hospitals (OR 1.01; 95% CI 0.96-1.03). The odds of mortality in minor teaching hospitals decreased 4.2% relative to nonteaching hospitals during the seven-year period (OR from 0.98 to 0.94). There was no consistent pattern of association between teaching status and patient severity.
Conclusions: After correctly accounting for the ability of nonteaching hospitals to appropriately transfer patients in need of different care, there was no survival benefit on average for initial admission to a teaching hospital for AMI. Further more, higher-risk patients did not benefit from initial admission to teaching hospitals.