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, p-POSSUM, and Cr-POSSUM: Implementation Issues in a United States Health Care System for Prediction of Outcome for Colon Cancer Resection
PURPOSE : The Physiologic and Operative Severity Score for the enUmeration of Mortality and morbidity ( POSSUM ) , Portsmouth revision (p)-POSSUM , and colorectal (Cr)-POSSUM scoring systems were developed as audit tools for comparing outcomes in surgical and colorectal patients on the basis of operative risk assessment . The aim of this study was to evaluate the applicability of these systems to a cohort of colon cancer patients undergoing surgery in the United States . METHODS : POSSUM factors from 890 consecutive patients undergoing major surgical procedures for colon cancer in nine United States hospitals over a two-year period from January 2000 through December 2001 were prospect ively collected . The observed over the expected hospital mortality was compared by means of the POSSUM , p-POSSUM , and Cr-POSSUM scoring systems . The effect of missing data on the utility of this process for outcome assessment was assessed with three methods for data imputation . RESULTS : The number of resections per institution ranged from 13 to 437 . The observed mortality rate ranged from 0.8 percent to 15.4 percent among the institutions , with an overall operative mortality of 2.3 percent . The POSSUM , p-POSSUM , and Cr-POSSUM predicted mortality was 10.7 percent , 11.2 percent , and 4.9 percent , respectively . The POSSUM and p-POSSUM models overpredicted mortality in all institutions ( P < 0.01 ) , whereas the Cr-POSSUM demonstrated an observed over expected hospital mortality ratio of > 1 in three institutions . The calculations were unaffected by the various methods of inserting missing data . CONCLUSION : An apparent overprediction of mortality for colon cancer resection was evident with all three POSSUM variants . This implies that a calibration process is required for use of these variants in the United States health care system . Missing data may be treated as normal values without influencing outcome . The Cr-POSSUM appeared to be the most promising audit tool for colorectal cancer surgery ; however , it will require further refinement to provide process control graphs for identification of potential outliers and improvement in the quality of care in the United States
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 .