[Validation of the EuroSCORE probabilistic model in patients undergoing coronary bypass grafting].

INTRODUCTION AND OBJECTIVES

EuroSCORE utilizes a probabilistic model for predicting the risk of in-hospital mortality in patients undergoing cardiac surgery. It is a useful instrument for evaluating quality of care. The model has two variants: the logistic EuroSCORE and the additive EuroSCORE. The aim of this study was to validate the EuroSCORE model in patients undergoing surgery at Hospital Clínic in Barcelona, Spain, and to compare the results obtained with the two variants.

METHODS

The study included all patients who received a coronary artery bypass graft (CABG) at Hospital Clínic in Barcelona in two consecutive years. The model's validity was assessed on the basis of its calibration (using the Hosmer-Lemeshow test) and its discrimination (using the receiver operating characteristic [ROC] curve). The two models were compared by carrying out a descriptive analysis of mortality for the whole group and for different risk groups, and by determining the models' discriminative power.

RESULTS

A total of 498 patients underwent CABG surgery and were included in the study. The Hosmer-Lemeshow test showed that the model's calibration was satisfactory (P=.32) and the area under the ROC curve was 0.83. The observed in-hospital mortality rate was 5.8%. The predicted rate was 4.2% with the logistic EuroSCORE and 3.9% with the additive EuroSCORE. Large differences were observed in high-risk patients. In these patients, the mortality predicted by the logistic variant was closer to the actual mortality.

CONCLUSIONS

EuroSCORE's validity was found to be satisfactory and the model can be used to evaluate quality of care. In high-risk patients, mortality estimated using the logistic model was closer to the actual mortality.