Elderly POSSUM, a dedicated score for prediction of mortality and morbidity after major colorectal surgery in older patients

Background: Several scores have been developed to evaluate surgical unit mortality and morbidity. The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and derivatives use preoperative and intraoperative factors, whereas the Surgical Risk Scale (SRS) and Association Francaise de Chirurgie (AFC) score use four simple factors. To allow for advanced age in patients undergoing colorectal surgery, a dedicated score - the Elderly (E) POSSUM - has been developed and its accuracy compared with these scores. Methods: From 2002 to 2004, 1186 elderly patients, at least 65 years old, undergoing major colorectal surgery in France were enrolled. Accuracy was assessed by calculating the area under the receiver operating characteristic curve (AUC) (discrimination) and calibration. Results: The mortality and morbidity rates were 9 and 41 per cent respectively. The E-POSSUM had both a good discrimination (AUC = 0.86) and good calibration (P = 0.178) in predicting mortality and a reasonable discrimination (AUC = 0.77) and good calibration (P = 0.166) in predicting morbidity. The E-POSSUM was significantly better at predicting mortality and morbidity than the AFC score (P(c) = 0.014 and P(c) < 0.001 respectively). Conclusion: The E-POSSUM is a good tool for predicting mortality, and the only efficient scoring system for predicting morbidity after major colorectal surgery in the elderly.