Acute Myocardial Infarction and Coronary Artery Bypass Grafting Outcomes in Specialty and General Hospitals

Analysis of State Inpatient Data

Health care is rife with contentious debates involving providers, regulators and policy-makers. Among those, has been the wrangle over whether physician-owned specialty hospitals truly offer improved patient outcomes versus competing general hospitals, or whether they simply siphon off low-risk, well-insured patients.

Previous research on this question examined Medicare data and has found improved outcomes in specialty hospitals. This study aimed to look at the non-Medicare population by using all-payer State Inpatient Data to compare mortality in adult patients admitted with acute myocardial infarction (AMI) or undergoing coronary artery bypass graft (CABG) in specialty cardiac versus general hospitals. Data was used from Texas, California, Arizona and Wisconsin for various years between 2000-2005 due to the number of physician-owned hospitals in these states and the quality of information available. The 10 specialty hospitals included in the study admitted 5,271 AMI patients and 7,520 CABG patients. The 58 general hospitals with which the specialty hospitals competed, admitted 47,138 AMI patients and 34,945 CABG patients.

Key Findings:

  • Overall, patients with AMI were 33 percent less likely to die if they were treated in a specialty hospital than if they were treated in a general hospital. Patients undergoing CABG in a specialty hospital were 20 percent less likely to die.
  • These advantages of specialty hospitals persisted when they were compared not only to general hospitals in their immediate area, but to general hospitals statewide. This is a small but important expansion of comparison.
  • Whether patients were insured by Medicare or non-Medicare plans, those admitted to specialty hospitals for AMI or CABG were less likely to be women or black than patients with the same condition and with similar insurances, admitted to general hospitals.
  • Specialty hospital AMI patients also had less of most, but not all, comorbid conditions, such as diabetes and renal failure.
  • After adjusting for such patient characteristics and comorbidity, statistically significant differences in mortality remained for AMI and CABG; however, when the study also adjusted for patient volume in the hospitals, the differences were no longer statistically significant for CABG.

Despite some limitations in the data and the study, as well as the after-adjustment statistical insignificance of improved outcomes for CABG patients, the authors believe this work adds to the body of research that demonstrates specialty hospitals are able to deliver modest improvements in patient outcomes compared to general hospitals. The researchers think this advantage should be acknowledged and is important to patients, policy-makers and physicians.