title: The EuroSCORE in western Denmark: a population-based study.
abstract: OBJECTIVE
  The present study aimed to examine the predictive performance of the logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) in a large cohort of patients undergoing cardiac surgery from 1999 through 2010 because methodologic shortcomings have hampered many previous studies questioning its predictive performance.
  
  
  METHODS
  Population-based prospectively registered data.
  
  
  METHODS
  The Western Denmark Heart Registry, a multi-institutional registry.
  
  
  METHODS
  Twenty-one thousand six hundred sixty-four patients.
  
  
  METHODS
  On-pump cardiac surgery.
  
  
  RESULTS
  The predictive ability of the logistic EuroSCORE was assessed using the area under the curve (AUC) for the discrimination test, the Hosmer-Lemeshow (HL) calibration test, and the mean estimated-to-observed mortality ratio (E/O). The overall AUC was 0.79 (95% confidence interval [CI] 0.77-0.81; HL test, p < 0.01; E/O 1.9). For coronary artery bypass grafting, the AUC was 0.78 (95% CI 0.75-0.81; HL test, p < 0.01; E/O 2.3). For coronary artery bypass grafting plus valve replacement, the AUC was 0.69 (95% CI 0.65-0.73; HL test, p = 0.02; E/O 1.5). For aortic valve replacement, the AUC was 0.76 (95% CI 0.72-0.80; HL test, p < 0.01; E/O 2.5). The overall and procedural specific E/O ratios tended to increase from 1999 to 2010. Mortality was overestimated across all levels of estimated risk, and in low-to-medium-risk patients, this overestimation increased most notably with time.
  
  
  CONCLUSIONS
  The EuroSCORE provides moderate-to-good discrimination and poor calibration. Despite substantial changes in risk factors during the study period, the EuroSCORE consistently overestimated 30-day mortality independent of the preoperative risk level and surgical procedure performed, indicating improved quality of surgery and patient care.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark. majlund@ki.au.dk
authors.forename: Martin Majlund
authors.initials: MM
authors.lastname: Mikkelsen
authors.forename: Søren Paaske
authors.initials: SP
authors.lastname: Johnsen
authors.forename: Per Hostrup
authors.initials: PH
authors.lastname: Nielsen
authors.forename: Carl-Johan
authors.initials: CJ
authors.lastname: Jakobsen
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000401:mortality*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D012720:Severity of Illness Index