title: Evaluation of O-POSSUM in predicting in-hospital mortality after resection for oesophageal cancer.
abstract: BACKGROUND
  The aims of the present study were to validate the Physiological and Operative Severity Score for the enUmeration of Mortality adjusted for oesophagogastric surgery (O-POSSUM).
  
  
  METHODS
  Data on patients who underwent potentially curative oesophagectomy in a tertiary referral centre for adenocarcinoma or squamous cell carcinoma of the oesophagus were analysed. The in-hospital mortality predicted by O-POSSUM was compared with the actual value by linear analysis.
  
  
  RESULTS
  Twenty-four (3.6 per cent) of 663 patients died in hospital. The observed : predicted ratio for in-hospital mortality was 0.29. The model had a poor fit (P < 0.001). The area under the receiver-operator characteristic curve was 0.60 (95 per cent confidence interval 0.47 to 0.72); P = 0.113). O-POSSUM score was not related to the severity of complications.
  
  
  CONCLUSIONS
  O-POSSUM overpredicted in-hospital mortality threefold and could not identify patients at higher risk of death. O-POSSUM needs substantial modification before it can be used for comparison of treatment outcomes between centres.
authors.affiliation: Department of Surgery, Academic Medical Centre at the University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. s.lagarde@slaz.nl
authors.forename: S M
authors.initials: SM
authors.lastname: Lagarde
authors.forename: A K D
authors.initials: AK
authors.lastname: Maris
authors.forename: S M M
authors.initials: SM
authors.lastname: de Castro
authors.forename: O R C
authors.initials: OR
authors.lastname: Busch
authors.forename: H
authors.initials: H
authors.lastname: Obertop
authors.forename: J J B
authors.initials: JJ
authors.lastname: van Lanschot
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000601:surgery; D004938:Esophageal Neoplasms / Q000401:mortality* / Q000601:surgery; D016629:Esophagectomy / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012720:Severity of Illness Index