title: Value and limitations of the BAR-score for donor allocation in liver transplantation.
abstract: OBJECTIVE
  The MELD-score was shown to be able to predict 90-day mortality in most patients with end-stage liver disease prior to liver transplantation and is used as a widely accepted measure for transplantation urgency. Prognostic ability of the BAR-score to predict 90-day post-transplant mortality by detection of unfavourable pretransplant combinations of donor and recipient factors may help to better balance urgency versus utility.
  
  
  METHODS
  Two German cohorts (Hannover, n=453; Kiel, n=234) were retrospectively analyzed using ROC-curve analysis, goodness-of-model-fit tests, summary measures and risk-adjusted multivariate binary regression. Included were all consecutive liver transplants performed in adult recipients (minimum age 18 years). Excluded were all combined transplants and living-related organ donor transplants.
  
  
  RESULTS
  Risk-adjusted multivariate regression revealed that the BAR-score is an independent risk factor for 90-day mortality after transplantation in both cohorts from Hannover and Kiel combined (p<0.001, OR=1.017, 95% CI:1.031-1.113). The area under the ROC-curve (AUROC) for the prediction of 90-day mortality using the BAR-score was 0.662 (95% CI 0.624-0.699, power>95%). Measures for association between observed 90-day mortality and the predicted probabilities in the combined cohort were concordant in 63.5% with low summary measures (Somers' D test 0.32, Goodman-Kruskal Gamma test 0.34 and Kendall's Tau a test 0.07).
  
  
  CONCLUSIONS
  The BAR-score performed below accepted thresholds for potentially useful clinical prognostic models. Prognostic models with better predictive ability with AUROCs>0.700, concordance>70% and larger summary measures are required for the prediction of 90-day post-transplant mortality to enable donor organ allocation with reliable weighing of urgency versus utility.
authors.affiliation: General, Visceral and Transplantation Surgery, Hanover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany, schrem.harald@mh-hannover.de.
authors.forename: Harald
authors.initials: H
authors.lastname: Schrem
authors.forename: Anna-Luise
authors.initials: AL
authors.lastname: Platsakis
authors.forename: Alexander
authors.initials: A
authors.lastname: Kaltenborn
authors.forename: Armin
authors.initials: A
authors.lastname: Koch
authors.forename: Courtney
authors.initials: C
authors.lastname: Metz
authors.forename: Marc
authors.initials: M
authors.lastname: Barthold
authors.forename: Christian
authors.initials: C
authors.lastname: Krauth
authors.forename: Volker
authors.initials: V
authors.lastname: Amelung
authors.forename: Felix
authors.initials: F
authors.lastname: Braun
authors.forename: Thomas
authors.initials: T
authors.lastname: Becker
authors.forename: Jürgen
authors.initials: J
authors.lastname: Klempnauer
authors.forename: Benedikt
authors.initials: B
authors.lastname: Reichert
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D016031:Liver Transplantation / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D014019:Tissue Donors