title: POSSUM and its related models as predictors of postoperative mortality and morbidity in patients undergoing surgery for gastro-oesophageal cancer: a systematic review.
abstract: BACKGROUND
  Gastro-oesophageal surgery is associated with appreciable postoperative morbidity and mortality. POSSUM (Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity) and its related models P-POSSUM and O-POSSUM have been developed to predict such events in general surgery. The aim was to undertake the first systematic review of the use of these models in gastro-oesophageal surgery patients.
  
  
  METHODS
  An online database search was carried out from 1991 to December 2008.
  
  
  RESULTS
  Twenty-two published studies in gastro-oesophageal cancer surgery were identified. Twelve studies were found not to address the above aim, leaving ten relevant publications for analysis. Pooled data from these studies showed the weighted observed-to-expected ratio (O/E) for postoperative mortality using POSSUM (n = 1189), P-POSSUM (n = 2314), and O-POSSUM (n = 1755) was 0.37, 0.83, and 0.51, respectively. The weighted O/E for morbidity using POSSUM (n = 1038) was 0.86.
  
  
  CONCLUSIONS
  POSSUM and O-POSSUM most significantly overestimated postoperative mortality in gastro-oesophageal cancer patients. In contrast, P-POSSUM had the least overestimation and may be the most useful predictor of likely postoperative mortality in these patients.
authors.affiliation: University Department of Surgery, Faculty of Medicine, University of Glasgow, 4th Floor Walton Building, Glasgow Royal Infirmary, Castle Street, Glasgow G4 0SF, UK. sdutta09@gmail.com
authors.forename: Sumanta
authors.initials: S
authors.lastname: Dutta
authors.forename: Paul G
authors.initials: PG
authors.lastname: Horgan
authors.forename: Donald C
authors.initials: DC
authors.lastname: McMillan
mesh_terms: D000368:Aged; D019540:Area Under Curve; D013505:Digestive System Surgical Procedures / Q000401:mortality*; D004938:Esophageal Neoplasms / Q000401:mortality / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013274:Stomach Neoplasms / Q000401:mortality / Q000601:surgery*