title: The Society of Thoracic Surgeons: 30-day operative mortality and morbidity risk models.
abstract: BACKGROUND
  Although 30 day risk-adjusted operative mortality (ROM) has been used for quality assessment, it is not sufficient to describe the outcomes after coronary artery bypass grafting (CABG) surgery. Risk-adjusted major morbidity may differentially impact quality of care (as complications occur more frequently than death) and enhance a surgical team's ability to assess their quality. This study identified the preoperative risk factors associated with several complications and a composite outcome (the presence of any major morbidity or 30-day operative mortality or both).
  
  
  METHODS
  For CABG procedures, the 1997 to 1999 Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database was used to develop ROM and risk-adjusted morbidity (ROMB) models. Risk factors were selected using standard STS univariate screening and multivariate logistic regression approaches. Risk model performance was assessed. Across STS participating sites, the association of observed-to-expected (O/E) ratios for ROM and ROMB was evaluated.
  
  
  RESULTS
  The 30-day operative death and major complication rates for STS CABG procedures were 3.05% and 13.40%, respectively (503,478 CABG procedures), including stroke (1.63%), renal failure (3.53%), reoperation (5.17%), prolonged ventilation (5.96%), and sternal infection (0.63%). Risk models were developed (c-indexes for stroke [0.72], renal failure [0.76], reoperation [0.64], prolonged ventilation [0.75], sternal infection [0.66], and the composite endpoint [0.71]). Only a slight correlation was found, however, between ROMB and ROM indicators.
  
  
  CONCLUSIONS
  Used in combination, ROMB and ROM may provide the surgical team with additional information to evaluate the quality of their care as well as valuable insights to allow them to focus on areas for improvement.
authors.affiliation: Denver Department of Veterans Affairs Medical Center, Denver, Colorado 80220, USA. laurie.shroyer@med.va.gov
authors.forename: A Laurie W
authors.initials: AL
authors.lastname: Shroyer
authors.forename: Laura P
authors.initials: LP
authors.lastname: Coombs
authors.forename: Eric D
authors.initials: ED
authors.lastname: Peterson
authors.forename: Mary C
authors.initials: MC
authors.lastname: Eiken
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: DeLong
authors.forename: Anita
authors.initials: A
authors.lastname: Chen
authors.forename: T Bruce
authors.initials: TB
authors.lastname: Ferguson
authors.forename: Frederick L
authors.initials: FL
authors.lastname: Grover
authors.forename: Fred H
authors.initials: FH
authors.lastname: Edwards
mesh_terms: D000368:Aged; D019985:Benchmarking / Q000706:statistics & numerical data; D002423:Cause of Death; D015897:Comorbidity; D001026:Coronary Artery Bypass / Q000401:mortality*; D003327:Coronary Disease / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality*; D011787:Quality of Health Care / Q000706:statistics & numerical data; D012307:Risk Factors; D016019:Survival Analysis; D014481:United States