title: Hospital Surgical Volumes and Mortality after Coronary Artery Bypass Grafting: Using International Comparisons to Determine a Safe Threshold.
abstract: OBJECTIVE
  To estimate a safe minimum hospital volume for hospitals performing coronary artery bypass graft (CABG) surgery.
  
  
  METHODS
  Hospital data on all publicly funded CABG in five European countries, 2007-2009 (106,149 patients).
  
  
  METHODS
  Hierarchical logistic regression models to estimate the relationship between hospital volume and mortality, allowing for case mix. Segmented regression analysis to estimate a threshold.
  
  
  RESULTS
  The 30-day in-hospital mortality rate was 3.0 percent overall, 5.2 percent (95 percent CI: 4.0-6.4) in low-volume hospitals, and 2.1 percent (95 percent CI: 1.8-2.3) in high-volume hospitals. There is a significant curvilinear relationship between volume and mortality, flatter above 415 cases per hospital per year.
  
  
  CONCLUSIONS
  There is a clear relationship between hospital CABG volume and mortality in Europe, implying a "safe" threshold volume of 415 cases per year.
authors.affiliation: Centre for Health Economics, University of York, York, UK.
authors.forename: Nils
authors.identifier: http://orcid.org/0000-0002-2833-0621
authors.initials: N
authors.lastname: Gutacker
authors.affiliation: Department of Health Sciences, University of York, York, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Bloor
authors.affiliation: Centre for Health Economics, University of York, York, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Cookson
authors.affiliation: Division of Epidemiology and Biostatistics, University of Leeds, UK.
authors.forename: Chris P
authors.initials: CP
authors.lastname: Gale
authors.affiliation: Department of Health Sciences, University of York, York, UK.
authors.forename: Alan
authors.initials: A
authors.lastname: Maynard
authors.affiliation: Department of Cardiothoracic Surgery, University Hospital Birmingham Queen Elizabeth, Edgbaston, UK.
authors.forename: Domenico
authors.initials: D
authors.lastname: Pagano
authors.affiliation: Department of Cardiovascular Surgery, Hospital Clinic de Barcelona, Barcelona, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Pomar
authors.affiliation: Institute for Health Sciences, IIS Aragón, Zaragoza, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Bernal-Delgado
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001026:Coronary Artery Bypass / Q000401:mortality* / Q000592:standards; D003718:Denmark / Q000453:epidemiology; D003953:Diagnosis-Related Groups; D004739:England / Q000453:epidemiology; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011174:Portugal / Q000453:epidemiology; D017524:Slovenia / Q000453:epidemiology; D013030:Spain / Q000453:epidemiology; D013503:Surgery Department, Hospital / Q000592:standards / Q000706:statistics & numerical data*; D013514:Surgical Procedures, Operative / Q000706:statistics & numerical data
keywords: Coronary artery bypass surgery; center-volume; international comparisons; mortality