Validation of the European System for Cardiac Operative Risk Evaluation-II model in an urban Indian population and comparison with three other risk scoring systems

AIMS AND OBJECTIVES: The aims were to compare the European System for Cardiac Operative Risk Evaluation (EuroSCORE)-II system against three established risk scoring systems for predictive accuracy in an urban Indian population and suggest improvements or amendments in the existing scoring system for adaptation in Indian population. MATERIALS AND METHODS: EuroSCORE-II, Parsonnet score, System-97 score, and Cleveland score were obtained preoperatively for 1098 consecutive patients. EuroSCORE-II system was analyzed in comparison to each of the above three scoring systems in an urban Indian population. Calibrations of scoring systems were assessed using Hosmer–Lemeshow test. Areas under receiver operating characteristics (ROC) curves were compared according to the statistical approach suggested by Hanley and McNeil. RESULTS: All EuroSCORE-II subgroups had highly significant P values stating good predictive mortality, except high-risk group (P = 0.175). The analysis of ROC curves of different scoring systems showed that the highest predictive value for mortality was calculated for the System-97 score followed by the Cleveland score. System-97 revealed extremely high predictive accuracies across all subgroups (curve area >80%). This difference in predictive accuracy was found to be statistically significant (P < 0.001). CONCLUSIONS: The present study suggests that the EuroSCORE-II model in its present form is not validated for use in the Indian population. An interesting observation was significantly accurate predictive abilities of the System-97 score.