Severity-Adjusted Mortality Rates: The Case of CABG Surgery / 예방의학회지

ABSTRACT

OBJECTIVES: To develop a model that will predict the mortality of patients undergoing Coronary Artery Bypass Graft (CABG) and evaluate the performance of hospitals. METHODS: Data from 564 CABGs performed in six general hospitals were collected through medical record abstraction by registered nurses. Variables studied involved risk factors determined by severity measures. Risk modeling was performed through logistic regression and validated with cross-validation. The statistical performance of the developed model was evaluated using c-statistic, R2, and Hosmer-Lemeshow statistic. Hospital performance was assessed by severity-adjusted mortalities. RESULTS: The developed model included age, sex, BUN, EKG rhythm, Congestive Heart Failure at admission, acute mental change within 24 hours, and previous angina pectoris history. The c-statistic and R2 were 0.791 and 0.101, respectively. Hosmer-Lemeshow statistic was 10.3(p value=0.2415). One hospital had a significantly higher mortality rate than the average mortality rate, while others were not significantly different. CONCLUSION: Comparing the quality of service by severity adjusted mortality rates, there were significant differences in hospital performance. The severity adjusted mortality rate of CABG surgery may be an indicator for evaluating hospital performance in Korea.