Assessment of coronary artery bypass graft surgery performance in New York. Is there a bias against taking high-risk patients?

OBJECTIVES: The purpose of this study was to determine whether performing coronary artery bypass surgery on high-risk patients adversely affects the risk-adjusted mortality rates for patients of surgeons and hospitals in New York State compared with the impact of performing surgery on more routine patients.

METHODS: Risk-adjusted mortality-rates were calculated for 31 hospitals and 87 surgeons for high-risk (a predicted mortality rate of at least 7.5%) and low-risk patients during the time period 1990 to 1992.

RESULTS: The risk-adjusted mortality for all high-risk patients was lower (2.94%) than the risk-adjusted mortality for other patients (3.02%). Fifteen of the 31 hospitals had a lower risk-adjusted mortality for all patients than they did for low-risk patients only, and no differences in either direction were statistically significant. Forty-one of 87 surgeons (47%) had risk-adjusted mortality for all patients that was at least as low as the risk-adjusted mortality for low-risk patients. In general, hospitals and surgeons with the lowest risk-adjusted mortality for all cases also had the lowest risk-adjusted mortality for high-risk cases.

CONCLUSIONS: The authors conclude that there is no systematic bias against operating on high-risk coronary artery bypass graft patients in the risk-adjusted performance system in New York.