Accuracy of two scoring systems for risk stratification in thoracic surgery

Abstract

We investigate the suitability of the two existing risk stratification systems available for predicting mortality in a cohort of patients undergoing lung resection under a single surgeon. Data from the 290 consecutive patients who underwent pulmonary resection between January 2008 and January 2011 were extracted from a prospective clinical data base. In-hospital mortality risk scores are calculated for every patient by using Thoracoscore and ESOS.01 and were compared with actual in-hospital mortality. The receiver operating characteristic (ROC) curve was used to establish how well the systems rank for predicting patient mortality. Actual in-hospital mortality was 3.1% (n = 9). Thoracoscore and ESOS values (mean ± SEM) were 4.93 ± 0.32 and 4.08 ± 0.41, respectively. The area under the ROC curve values for ESOS and Thoracoscore were 0.8 and 0.6, respectively. ESOS was reasonably accurate at predicting the overall mortality (sensitivity 88% and specificity 67%), whereas Thoracoscore was a weaker predictor of mortality (sensitivity 67% and specificity 53%). The ESOS score had better predictive values in our patient population and might be easier to calculate. Because of their low specificity, the use of these scores should be limited to the assessment of outcomes of surgical cohorts, but they are not designed to predict risks for individual patients.