Comparison of Surgical Risk Score, POSSUM and p-POSSUM in higher-risk surgical patients

Abstract

Abstract Background Much current interest is focused on the use of the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and the Portsmouth predictor equation (p-POSSUM) for risk-adjusted surgical audit. The Surgical Risk Score (SRS) has been shown to offer an equivalent accuracy, but was validated using a cohort that contained a high proportion of low-risk patients. The aim of this study was to compare the accuracy of mortality prediction using SRS with that of POSSUM and p-POSSUM in a cohort of higher-risk patients. Methods Some 949 consecutive patients undergoing inpatient surgical procedures in a district general hospital under the care of a single surgeon were analysed. Results The observed 30-day mortality rate was 8·4 per cent. Mean mortality rates predicted using SRS, POSSUM and p-POSSUM scores were 5·9, 12·6 and 7·3 per cent respectively. No significant difference was observed in the area under the receiver–operator characteristic curves for the three methods. Conclusion The SRS accurately predicted mortality in higher-risk surgical patients. The accuracy of prediction equalled that of POSSUM and p-POSSUM.