title: Comparison of a Vascular Study Group of New England risk prediction model with established risk prediction models of in-hospital mortality after elective abdominal aortic aneurysm repair.
abstract: BACKGROUND
  A certain number of deaths may result from elective abdominal aortic aneurysm (AAA) repair due to inherent risks of operation; however, no agreement exists about which predictive model for in-hospital mortality is most accurate in predicting these events. This study developed a risk prediction model using Vascular Study Group of New England (VSGNE) data and compared it with established models.
  
  
  METHODS
  VSGNE data (2003-2013) were queried for patients undergoing elective AAA repair by open or endovascular techniques. Clinical variables and known predictors of mortality were included in a full prediction model. Backward elimination with α = .2 was used to construct a parsimonious model. This VSGNE model was compared with established models-Medicare, Glasgow Aneurysm Score (GAS), and Vascular Governance North West (VGNW)-based on the scope of VSGNE data collection. Model fit was compared with the Vuong test. Model discrimination was compared in equally sized risk-group VSGNE terciles.
  
  
  RESULTS
  The overall mortality rate for 4431 elective AAA patients was 1.4%. The discriminating ability of the VSGNE model was high (C statistic = 0.822) and corrected slightly to 0.779 after internal validation. Vuong tests yielded significant overall fit difference favoring the VSGNE model over the Medicare (C statistic = 0.769), VGNW (C statistic = 0.767), and GAS (C statistic = 0.685) models. The VGNW and Medicare models performed better than GAS in predicting mortality among risk-group terciles.
  
  
  CONCLUSIONS
  The VSGNE risk prediction model is best at forecasting mortality among this patient population. The Medicare and VGNW models showed good discrimination.
authors.affiliation: Division of Vascular and Endovascular Surgery, Boston University School of Medicine, Boston, Mass. Electronic address: mohammad.eslami@bmc.org.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Eslami
authors.affiliation: Department of Biostatistics, Boston School of Public Health, Boston, Mass.
authors.forename: Denis
authors.initials: D
authors.lastname: Rybin
authors.affiliation: Department of Biostatistics, Boston School of Public Health, Boston, Mass.
authors.forename: Gheorghe
authors.initials: G
authors.lastname: Doros
authors.affiliation: Department of Biostatistics, Boston School of Public Health, Boston, Mass.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kalish
authors.affiliation: Division of Vascular and Endovascular Surgery, Boston University School of Medicine, Boston, Mass.
authors.forename: Alik
authors.initials: A
authors.lastname: Farber
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D016009:Chi-Square Distribution; D016208:Databases, Factual; D003661:Decision Support Techniques; D016002:Discriminant Analysis; D017558:Elective Surgical Procedures; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D009511:New England / Q000453:epidemiology; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality*