title: Coronary artery bypass grafting: are risk models developed from on-pump surgery valid for off-pump surgery?
abstract: OBJECTIVE
  This study was undertaken to test whether risk models developed from on-pump coronary artery bypass grafting are valid for assessing the risk for off-pump coronary artery bypass grafting.
  
  
  METHODS
  From January 1997 through June 2002, a total of 12,845 patients underwent isolated coronary artery bypass grafting procedures in Providence Health System hospitals. Of these, 1782 operations (14%) were performed without cardiopulmonary bypass. An operative mortality risk model was derived from on-pump data with logistic regression. This model and two other external risk models developed from on-pump data were then applied to patients undergoing off-pump coronary artery bypass grafting to test the model adequacy.
  
  
  RESULTS
  Good model discrimination and calibration were obtained from all three models.
  
  
  CONCLUSIONS
  Operative mortality risk models developed from on-pump coronary artery bypass grafting can be used to assess the risk for off-pump coronary artery bypass grafting.
authors.affiliation: Providence Health System, Portland, OR, USA. yingxing.wu@providence.org
authors.forename: YingXing
authors.initials: Y
authors.lastname: Wu
authors.forename: Gary L
authors.initials: GL
authors.lastname: Grunkemeier
authors.forename: John R
authors.initials: JR
authors.lastname: Handy
mesh_terms: D000368:Aged; D002315:Cardiopulmonary Bypass / Q000379:methods; D015331:Cohort Studies; D001026:Coronary Artery Bypass / Q000379:methods* / Q000401:mortality*; D003327:Coronary Disease / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D006355:Heart-Lung Machine; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011336:Probability; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D015996:Survival Rate; D016896:Treatment Outcome