title: Surgeon specialization and operative mortality in United States: retrospective analysis.
abstract: OBJECTIVE
  To measure the association between a surgeon's degree of specialization in a specific procedure and patient mortality.
  
  
  METHODS
  Retrospective analysis of Medicare data.
  
  
  METHODS
  US patients aged 66 or older enrolled in traditional fee for service Medicare.
  
  
  METHODS
  25 152 US surgeons who performed one of eight procedures (carotid endarterectomy, coronary artery bypass grafting, valve replacement, abdominal aortic aneurysm repair, lung resection, cystectomy, pancreatic resection, or esophagectomy) on 695 987 patients in 2008-13.
  
  
  METHODS
  Relative risk reduction in risk adjusted and volume adjusted 30 day operative mortality between surgeons in the bottom quarter and top quarter of surgeon specialization (defined as the number of times the surgeon performed the specific procedure divided by his/her total operative volume across all procedures).
  
  
  RESULTS
  For all four cardiovascular procedures and two out of four cancer resections, a surgeon's degree of specialization was a significant predictor of operative mortality independent of the number of times he or she performed that procedure: carotid endarterectomy (relative risk reduction between bottom and top quarter of surgeons 28%, 95% confidence interval 0% to 48%); coronary artery bypass grafting (15%, 4% to 25%); valve replacement (46%, 37% to 53%); abdominal aortic aneurysm repair (42%, 29% to 53%); lung resection (28%, 5% to 46%); and cystectomy (41%, 8% to 63%). In five procedures (carotid endarterectomy, valve replacement, lung resection, cystectomy, and esophagectomy), the relative risk reduction from surgeon specialization was greater than that from surgeon volume for that specific procedure. Furthermore, surgeon specialization accounted for 9% (coronary artery bypass grafting) to 100% (cystectomy) of the relative risk reduction otherwise attributable to volume in that specific procedure.
  
  
  CONCLUSIONS
  For several common procedures, surgeon specialization was an important predictor of operative mortality independent of volume in that specific procedure. When selecting a surgeon, patients, referring physicians, and administrators assigning operative workload may want to consider a surgeon's procedure specific volume as well as the degree to which a surgeon specializes in that procedure.
authors.affiliation: Department of Economics, Harvard University, Cambridge, MA, USA McKinsey and Company, Boston, MA, USA nikhilsahni@fas.harvard.edu.
authors.forename: Nikhil R
authors.initials: NR
authors.lastname: Sahni
authors.affiliation: National Bureau of Economic Research, Cambridge, MA, USA.
authors.forename: Maurice
authors.initials: M
authors.lastname: Dalton
authors.affiliation: Department of Economics, Harvard University, Cambridge, MA, USA National Bureau of Economic Research, Cambridge, MA, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Cutler
authors.affiliation: Dartmouth-Hitchcock Health System, Lebanon, NH, USA Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, NH, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Birkmeyer
authors.affiliation: National Bureau of Economic Research, Cambridge, MA, USA Harvard Kennedy School, Cambridge, MA, USA.
authors.forename: Amitabh
authors.initials: A
authors.lastname: Chandra
mesh_terms: D000368:Aged; D013504:Cardiovascular Surgical Procedures / Q000401:mortality; D002983:Clinical Competence; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D006278:Medicare; D009369:Neoplasms / Q000601:surgery; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D013038:Specialization / Q000706:statistics & numerical data; D066231:Surgeons / Q000706:statistics & numerical data; D013514:Surgical Procedures, Operative / Q000401:mortality*; D014481:United States