title: Evaluation of P-POSSUM and O-POSSUM scores in patients with gastric cancer undergoing resection.
abstract: OBJECTIVE
  The aim of this study was to evaluate the predictive accuracy of P-POSSUM and O-POSSUM models on patients undergoing elective gastric resection.
  
  
  METHODS
  P-POSSUM and O-POSSUM predictor equations for mortality were applied retrospectively to 126 patients who had undergone elective gastrectomy for cancer. Observed mortality rates were compared with rates predicted by P-POSSUM and O-POSSUM using the Hosmer-Lemeshow goodness-of-fit test. Evaluation of the discriminative capability of both models was performed using receiver-operating characteristic (ROC) curve analysis.
  
  
  RESULTS
  Overall fourteen deaths were observed. O-POSSUM predicted 15 deaths (chi2=14.61, p=0.13) and P-POSSUM predicted 20 deaths (chi2=25.41, p=0.002) using the Hosmer-Lemeshow test. ROC curves analysis revealed that O-POSSUM had better discriminatory power for mortality compared to P-POSSUM (area under curve=0.880, for O-POSSUM and area under curve=0.703 for P-POSSUM).
  
  
  CONCLUSIONS
  These data suggest that O-POSSUM predicts mortality more accurately than P-POSSUM in patients undergoing elective gastrectomy for cancer.
authors.affiliation: Fifth Department of Surgery, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors.forename: Erdal
authors.initials: E
authors.lastname: Gocmen
authors.forename: Mahmut
authors.initials: M
authors.lastname: Koc
authors.forename: Mesut
authors.initials: M
authors.lastname: Tez
authors.forename: Mehmet
authors.initials: M
authors.lastname: Keskek
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kilic
authors.forename: Tamer
authors.initials: T
authors.lastname: Ertan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001707:Biopsy, Needle; D002423:Cause of Death; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005743:Gastrectomy / Q000379:methods / Q000401:mortality*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013274:Stomach Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D016019:Survival Analysis; D016896:Treatment Outcome