title: The 22/11 risk prediction model: a validated model for predicting 30-day mortality in patients with cirrhosis and spontaneous bacterial peritonitis.
abstract: OBJECTIVE
  Clinicians do not have a validated tool for estimating the short-term mortality associated with spontaneous bacterial peritonitis (SBP). Accurate prognosis assessment is important for risk stratification and for individualizing therapy. We aimed therefore to develop and validate a model for the prediction of 30-day mortality in SBP patients receiving standard medical treatment (antibiotics and if indicated by guidelines, intravenous albumin therapy).
  
  
  METHODS
  We retrospectively identified SBP patients treated at a tertiary care center between 2003 and 2011 (training set). Multivariate regression modeling and receiver operating characteristic (ROC) curves were utilized for statistical analysis. An external data set of 109 SBP patients was utilized for validation.
  
  
  RESULTS
  Of the 184 patients in the training set, 66% were men with a median age of 55 years, a median MELD (Model for End-Stage Liver Disease) score of 20, and a 30-day mortality of 27%. Peripheral blood leukocyte count ≥11×10⁹ cells/l (odds ratio (OR) 2.5; 95% confidence interval CI: 1.2-5.2) and MELD score ≥22 (OR 4.6; 95% CI: 2.3-9.6) were independent predictors of 30-day mortality. Patients with neither, one, or both variables had 30-day mortality rates of 8%, 32%, and 52%, respectively. The findings in the validation set mirrored the training set.
  
  
  CONCLUSIONS
  In cirrhotic patients with SBP receiving standard therapy, MELD score ≥22 and peripheral blood leukocyte count ≥11×10⁹ cells/l are validated independent predictors of mortality. The mortality in a patient without either poor prognostic variable is ≤10% and with both variables is ≥50%. Trials aiming to reduce mortality should target patients in the moderate-risk to high-risk groups.
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada. ptandon@ualberta.ca
authors.forename: Puneeta
authors.initials: P
authors.lastname: Tandon
authors.forename: Deepali
authors.initials: D
authors.lastname: Kumar
authors.forename: Yeon Seok
authors.initials: YS
authors.lastname: Seo
authors.forename: Hsiu-Ju
authors.initials: HJ
authors.lastname: Chang
authors.forename: Jennifer
authors.initials: J
authors.lastname: Chaulk
authors.forename: Michelle
authors.initials: M
authors.lastname: Carbonneau
authors.forename: Hina
authors.initials: H
authors.lastname: Qamar
authors.forename: Adam
authors.initials: A
authors.lastname: Keough
authors.forename: Nadia
authors.initials: N
authors.lastname: Mansoor
authors.forename: Mang
authors.initials: M
authors.lastname: Ma
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001424:Bacterial Infections / Q000150:complications / Q000188:drug therapy / Q000401:mortality*; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications / Q000188:drug therapy / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010538:Peritonitis / Q000150:complications / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D011379:Prognosis; D012189:Retrospective Studies; D012306:Risk; D018570:Risk Assessment
chemical_list: D000900:Anti-Bacterial Agents