Lower mortality rates at cardiac specialty hospitals traceable to healthier patients and to doctors' performing more procedures.

Physician-owned cardiac specialty hospitals advertise that they have outstanding physicians and results. To test this assertion, we examined who gets referred to these hospitals, as well as whether different results occur when specialty physicians split their caseloads among specialty and general hospitals in the same markets. Using data on 210,135 patients who underwent percutaneous coronary interventions in Texas during 2004-07, we found that the risk-adjusted in-hospital mortality rate for patients treated at specialty hospitals was significantly below the rate for all hospitals in the state (0.68 percent versus 1.50 percent). However, the rate was significantly higher when physicians who owned cardiac specialty hospitals treated patients in general hospitals (2.27 percent versus 1.50 percent). In addition, several patient characteristics were associated with a lower likelihood of being admitted to a cardiac hospital for cardiac care, such as being African American or Hispanic and having Medicaid or no health insurance. After adjustment for patient severity and number of procedures performed, the overall outcomes for cardiologists who owned specialty hospitals were not significantly different from the "average outcomes" obtained at noncardiac hospitals. In contrast to previous studies, patient outcomes were found to be highly dependent on the type of hospital where the procedure was performed. To remove a potential source of bias and achieve a more balanced comparison, the quality statistics reported by physician-owned cardiac hospitals should be adjusted to incorporate the high rates of poor outcomes for the many procedures done by their cardiologists at nearby noncardiac hospitals.