Conclusions P-POSSUM was the most accurate model for predicting post-operative mortality after colorectal cancer surgery .
The original POSSUM model was accurate in predicting post-operative complications
Introduction The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity  ( POSSUM ) model and its Portsmouth ( P-POSSUM ) and colorectal ( CR-POSSUM ) modifications are used extensively to predict and audit post-operative mortality and morbidity .
This aim of this systematic review was to assess the predictive value of the POSSUM models in colorectal cancer surgery .
POSSUM and Portsmouth POSSUM for predicting mortality. Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity.
BACKGROUND There is a need for an accurate measure of surgical outcomes so that hospitals and surgeons can be compared properly regardless of case mix . POSSUM ( Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity ) uses a physiological score and an operative severity score to calculate risks of mortality and morbidity . In a previous small study it was found that Portsmouth POSSUM ( P-POSSUM ; a modification of the POSSUM system ) provided a more accurate prediction of mortality . METHODS Some 10000 general surgical interventions ( excluding paediatric and day cases ) were studied prospect ively between August 1993 and November 1995 . The POSSUM mortality equation was applied to the full 10000 surgical episodes . The 10000 patients were arranged in chronological order and the first 2500 were used as a training set to produce the modified P-POSSUM predictor equation . This was then applied prospect ively to the remaining 7500 patients arranged chronologically in five groups of 1500 . RESULTS The original POSSUM logistic regression equation for mortality overpredicts the overall risk of death by more than twofold and the risk of death for patients at lowest risk ( 5 per cent or less ) by more than sevenfold . The P-POSSUM equation produced a very close fit with the observed in-hospital mortality . CONCLUSION P-POSSUM provides an accurate method for comparative surgical audit
Conclusions P-POSSUM was the most accurate model for predicting post-operative mortality after colorectal cancer surgery .
The original POSSUM model was accurate in predicting post-operative complications
Introduction The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity  ( POSSUM ) model and its Portsmouth ( P-POSSUM ) and colorectal ( CR-POSSUM ) modifications are used extensively to predict and audit post-operative mortality and morbidity .
This aim of this systematic review was to assess the predictive value of the POSSUM models in colorectal cancer surgery .