title: A comparison of POSSUM, P-POSSUM and colorectal POSSUM for the prediction of postoperative mortality in patients undergoing colorectal resection.
abstract: OBJECTIVE
  POSSUM (Physiologic and Operative Severity Score for enUmeration of Morbidity & Mortality) and P-POSSUM have been validated as scoring tools for the prediction of postoperative complications in general surgical patients. More recently a colorectal-specific POSSUM has been developed for mortality prediction. This study was designed to evaluate and compare the accuracy for mortality prediction of POSSUM, P-POSSUM, and colorectal POSSUM after major and complex major colorectal procedures.
  
  
  METHODS
  The relationship between the observed and expected morbidity and mortality was examined in 347 consecutive patients (321 elective, 26 urgent) undergoing a major or complex major colorectal resection using POSSUM, P-POSSUM, and Colorectal POSSUM. The accuracy of using these scoring tools to predict mortality was assessed using Receiver Operator Characteristic curve analysis.
  
  
  RESULTS
  A total of 347 consecutive patients (median age, 69 (range, 34-92) years) were assessed. Seventy-one patients (20.5 percent) suffered a postoperative complication and 15 patients (4.3 percent) died. The observed: expected POSSUM ratio for morbidity was 0.71 and mortality 0.68. The area under curve from Receiver Operator Characteristic curve analysis for POSSUM was 0.752. The observed:expected mortality ratio for P-POSSUM was 0.71, and the area under curve from Receiver Operator Characteristic curve analysis was 0.749. The observed:expected mortality ratio for colorectal POSSUM was 0.75, and the area under the curve from Receiver Operator Characteristic curve analysis was 0.781.
  
  
  CONCLUSIONS
  Colorectal POSSUM provides comparable prediction of mortality risk after colorectal resection compared with POSSUM and P-POSSUM.
authors.affiliation: Royal Berkshire Hospital, Reading, Berkshire, United Kingdom.
authors.forename: Thangiah
authors.initials: T
authors.lastname: Ramkumar
authors.forename: Vivien
authors.initials: V
authors.lastname: Ng
authors.forename: Lucy
authors.initials: L
authors.lastname: Fowler
authors.forename: Ridzuan
authors.initials: R
authors.lastname: Farouk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods; D012720:Severity of Illness Index; D006113:United Kingdom / Q000453:epidemiology