title: Association of allogeneic red-blood cell transfusion with surgeon case-volume.
abstract: BACKGROUND
  Surgeon case-volume predicts a variety of patient outcomes. We hypothesize that surgeon case-volume predicts RBC transfusion across different surgical procedures.
  
  
  METHODS
  We performed a cohort study of 372,670 in-patient surgical cases in the 52 non-federal hospitals in Maryland between 2004 and 2005. The main outcome measure was relative risk of receiving a transfusion.
  
  
  RESULTS
  Overall, 13.9% of patients received a transfusion. Patients seen by the highest case-volume surgeons (>161 cases/y) were more likely to receive a transfusion (16% versus 11%, P < 0.01) compared with middle case-volume surgeons (89-161 cases/y). After adjusting for confounders, the highest case-volume patients were still at increased risk of transfusion [relative risk (RR) 1.10, 1.07-1.14]. This result was true across many surgery types.
  
  
  CONCLUSIONS
  Surgeon case-volume is independently associated with the likelihood of RBC transfusion across a broad range of surgical procedures. Future efforts should be directed towards studying and standardization of transfusion practices.
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. Jpham3@jhmi.edu
authors.forename: Julius Cuong
authors.initials: JC
authors.lastname: Pham
authors.forename: Elliott R
authors.initials: ER
authors.lastname: Haut
authors.forename: Christina L
authors.initials: CL
authors.lastname: Catlett
authors.forename: Sean M
authors.initials: SM
authors.lastname: Berenholtz
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D017707:Erythrocyte Transfusion / Q000706:statistics & numerical data*; D005260:Female; D013502:General Surgery / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008396:Maryland; D008875:Middle Aged; D015233:Models, Statistical; D012189:Retrospective Studies; D012307:Risk Factors; D013503:Surgery Department, Hospital / Q000706:statistics & numerical data*