Objective: The purpose of this study was to evaluate the usefulness of EuroSCORE in terms of prediction of the outcome as a result of preoperative information in a cohort of patients.
Methods: We analyzed the data from 751 patients treated between Jan 1 and Dec 31, 1998. We used contingency tables and applied methods of discriminant analysis for the evaluation.
Results: Compared to the 14.799 patients from whose data the EuroSCORE system had originally been derived [1,2], we had a smaller portion of patients in the low-risk group (24.5% vs. 30.6%), a comparable portion of patients in the medium-risk group (42.2% vs. 40.5%) and a higher proportion of patients in the high-risk group (33.2% vs. 29.0%). This difference in the risk distributions was highly significant (p < 0.001). The application of the EuroSCORE system showed that deaths only occurred in the high-risk group in our hospital. We had 36 deaths amongst the patients, which gives an overall mortality rate of 4.9% and a mortality rate of 1.6% in the medium-risk group and of 12.4% in the high-risk group. The discriminant analysis showed that with the EuroSCORE as single predicting variable - virtually all survivors were classified correctly (giving a specificity of 99.0%). The sensitivity was rather low at only 25%; however, this means that many of the high-risk patients in our clinic survived. The total misclassification rate, however, was 12.7%. Additionally, we found that a higher score value predicts a significantly higher probability for perioperative complications and also results in significantly increased average times for the bypass and total time for surgery.
Conclusion: The EuroSCORE is a valuable score system for the prediction of the overall outcome of patients following open heart surgery, and is easy to use. As far as perioperative complications are concerned, however, some specifications seem desirable.