title: EuroSCORE vs. EuroSCORE II vs. Society of Thoracic Surgeons risk algorithm.
abstract: BACKGROUND
  This study presents a validation series for EuroSCORE II compared with the previous additive and logistic EuroSCORE and the Society of Thoracic Surgeons risk prediction algorithm.
  
  
  METHODS
  Clinical data of 2004 patients undergoing isolated coronary artery bypass surgery between 2006 and 2010 were retrospectively collected and individual expected risks of death were calculated by all 3 risk prediction algorithms. Performance of these risk algorithms was evaluated in terms of discrimination and calibration.
  
  
  RESULTS
  There were 76 deaths (3.8%) among 2004 patients. The mean EuroSCORE II predicted mortality was 3.72% ± 5.11%, additive EuroSCORE was 4.35%  ± 3.65% and logistic EuroSCORE was 6.41%  ± 10.06%. The additive EuroSCORE was better than EuroSCORE II in terms of both discrimination and calibration (C-statistic 0.866 and Hosmer-Lemeshow p value 0.230 vs. C-statistic 0.836 and Hosmer-Lemeshow p value 0.013 for EuroSCORE II). In a subset of 380 patients, we compared EuroSCORE II with the Society of Thoracic Surgeons risk prediction. Actual mortality was 2.89%. Predicted mortality by EuroSCORE II was 4.27%  ± 5.22% and Society of Thoracic Surgeons risk prediction was 2.30%  ± 4.16%. The area under the curve was 0.759 for EuroSCORE II and 0.898 for the Society of Thoracic Surgeons risk prediction, whereas the Hosmer-Lemeshow p value was 0.267 for EuroSCORE II and 0.981 for Society of Thoracic Surgeons risk prediction.
  
  
  CONCLUSIONS
  The Society of Thoracic Surgeons risk prediction algorithm is a better risk assessment tool compared to additive and logistic EuroSCORE and EuroSCORE II in Pakistani patients.
authors.affiliation: Cardiothoracic Surgery Department, Aga Khan University Hospital, Karachi, Pakistan.
authors.forename: Irfan
authors.initials: I
authors.lastname: Qadir
authors.forename: Sardar Muhammad
authors.initials: SM
authors.lastname: Alamzaib
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ahmad
authors.forename: Shazia
authors.initials: S
authors.lastname: Perveen
authors.forename: Hasanat
authors.initials: H
authors.lastname: Sharif
mesh_terms: D000368:Aged; D000465:Algorithms; D019540:Area Under Curve; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000401:mortality; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D003661:Decision Support Techniques; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010154:Pakistan; D018579:Patient Selection; D011183:Postoperative Complications / Q000209:etiology* / Q000401:mortality; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: Coronary artery bypass; Hospital mortality; Pakistan; Risk assessment; Severity of illness index