title: Comparison and clinical suitability of eight prediction models for cardiac surgery-related acute kidney injury.
abstract: BACKGROUND
  Cardiac surgery-related acute kidney injury (CS-AKI) results in increased morbidity and mortality. Different models have been developed to identify patients at risk of CS-AKI. While models that predict dialysis and CS-AKI defined by the RIFLE criteria are available, their predictive power and clinical applicability have not been compared head to head.
  
  
  METHODS
  Of 1388 consecutive adult cardiac surgery patients operated with cardiopulmonary bypass, risk scores of eight prediction models were calculated. Four models were only applicable to a subgroup of patients. The area under the receiver operating curve (AUROC) was calculated for all levels of CS-AKI and for need for dialysis (AKI-D) for each risk model and compared for the models applicable to the largest subgroup (n = 1243).
  
  
  RESULTS
  The incidence of AKI-D was 1.9% and for CS-AKI 9.3%. The models of Rahmanian, Palomba and Aronson could not be used for preoperative risk assessment as postoperative data are necessary. The three best AUROCs for AKI-D were of the model of Thakar: 0.93 [95% confidence interval (CI) 0.91-0.94], Fortescue: 0.88 (95% CI 0.87-0.90) and Wijeysundera: 0.87 (95% CI 0.85-0.89). The three best AUROCs for CS-AKI-risk were 0.75 (95% CI 0.73-0.78), 0.74 (95% CI 0.71-0.76) and 0.70 (95% CI 0.73-0.78), for Thakar, Mehta and both Fortescue and Wijeysundera, respectively. The model of Thakar performed significantly better compared with the models of Mehta, Rahmanian, Fortescue and Wijeysundera (all P-values <0.01) at different levels of severity of CS-AKI.
  
  
  CONCLUSIONS
  The Thakar model offers the best discriminative value to predict CS-AKI and is applicable in a preoperative setting and for all patients undergoing cardiac surgery.
authors.affiliation: Department of Intensive Care Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Harmke D
authors.initials: HD
authors.lastname: Kiers
authors.forename: Mark
authors.initials: M
authors.lastname: van den Boogaard
authors.forename: Micha C J
authors.initials: MC
authors.lastname: Schoenmakers
authors.forename: Johannes G
authors.initials: JG
authors.lastname: van der Hoeven
authors.forename: Henry A
authors.initials: HA
authors.lastname: van Swieten
authors.forename: Suzanne
authors.initials: S
authors.lastname: Heemskerk
authors.forename: Peter
authors.initials: P
authors.lastname: Pickkers
mesh_terms: D058186:Acute Kidney Injury / Q000453:epidemiology*; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity