title: Predictive models for kidney disease: improving global outcomes (KDIGO) defined acute kidney injury in UK cardiac surgery.
abstract: BACKGROUND
  Acute kidney injury (AKI) risk prediction scores are an objective and transparent means to enable cohort enrichment in clinical trials or to risk stratify patients preoperatively. Existing scores are limited in that they have been designed to predict only severe, or non-consensus AKI definitions and not less severe stages of AKI, which also have prognostic significance. The aim of this study was to develop and validate novel risk scores that could identify all patients at risk of AKI.
  
  
  METHODS
  Prospective routinely collected clinical data (n = 30,854) were obtained from 3 UK cardiac surgical centres (Bristol, Birmingham and Wolverhampton). AKI was defined as per the Kidney Disease: Improving Global Outcomes (KDIGO) Guidelines. The model was developed using the Bristol and Birmingham datasets, and externally validated using the Wolverhampton data. Model discrimination was estimated using the area under the ROC curve (AUC). Model calibration was assessed using the Hosmer-Lemeshow test and calibration plots. Diagnostic utility was also compared to existing scores.
  
  
  RESULTS
  The risk prediction score for any stage AKI (AUC = 0.74 (95% confidence intervals (CI) 0.72, 0.76)) demonstrated better discrimination compared to the Euroscore and the Cleveland Clinic Score, and equivalent discrimination to the Mehta and Ng scores. The any stage AKI score demonstrated better calibration than the four comparison scores. A stage 3 AKI risk prediction score also demonstrated good discrimination (AUC = 0.78 (95% CI 0.75, 0.80)) as did the four comparison risk scores, but stage 3 AKI scores were less well calibrated.
  
  
  CONCLUSIONS
  This is the first risk score that accurately identifies patients at risk of any stage AKI. This score will be useful in the perioperative management of high risk patients as well as in clinical trial design.
authors: Kate
authors: K
authors: Birnie
authors: Veerle
authors: V
authors: Verheyden
authors: Domenico
authors: D
authors: Pagano
authors: Moninder
authors: M
authors: Bhabra
authors: Kate
authors: K
authors: Tilling
authors: Jonathan A
authors: JA
authors: Sterne
authors: Gavin J
authors: GJ
authors: Murphy
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011184:Postoperative Period; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D003404:Creatinine