title: Volume-based referral for cancer surgery: informing the debate.
abstract: OBJECTIVE
  Mounting evidence suggests a relationship between hospital volume and outcomes after major cancer surgery; however, the absolute benefits of volume-based referral on a national basis are unclear.
  
  
  METHODS
  Data from the Nationwide Inpatient Sample were used to measure the likelihood of operative mortality and a prolonged length of stay (LOS) after six cancer surgeries (prostatectomy, cystectomy, esophagectomy, pancreatectomy, pneumonectomy, and liver resection) between 1993 and 2003. Using sampling weights, the adjusted likelihood of the outcomes was used to calculate the number of lives saved (or prolonged LOS avoided) in the United States.
  
  
  RESULTS
  The magnitude of the volume-operative mortality effect varied from an adjusted odds ratio (OR) of 1.3 (95% CI, 0.8 to 2.3) for cystectomy to 4.9 (95% CI, 2.4 to 10.1) for pancreatectomy. After accounting for varying rates of procedure utilization, the lives saved per 100 surgeries regionalized ranged from 0.2 (95% CI, 0.12 to 0.24 lives saved) for prostatectomy to 9.2 (95% CI, 6.7 to 10.4 lives saved) for pancreatectomy. The volume-prolonged LOS effect varied from an adjusted OR of 0.9 (95% CI, 0.5 to 1.6) for liver resection to 4.8 (95% CI, 3.5 to 6.7) for prostatectomy. After accounting for procedure use, the number of prolonged hospitalizations avoided ranged from -1.7 (95% CI, -11.3 to 3.6 hospitalizations) to 14.3 (95% CI, 12.9 to 15.4 hospitalizations) per 100 surgeries regionalized for liver resection and prostatectomy, respectively.
  
  
  CONCLUSIONS
  For patients undergoing major cancer surgery, the benefits of volume-based referral depend on the interplay between procedure utilization, the magnitude of effect, and the outcome chosen.
authors.affiliation: Department of Urology, University of Michigan, Ann Arbor, MI, USA. bhollen@umich.edu
authors.forename: Brent K
authors.initials: BK
authors.lastname: Hollenbeck
authors.forename: Rodney L
authors.initials: RL
authors.lastname: Dunn
authors.forename: David C
authors.initials: DC
authors.lastname: Miller
authors.forename: Stephanie
authors.initials: S
authors.lastname: Daignault
authors.forename: David A
authors.initials: DA
authors.lastname: Taub
authors.forename: John T
authors.initials: JT
authors.lastname: Wei
mesh_terms: D000368:Aged; D005260:Female; D006761:Hospitals; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000601:surgery*; D017063:Outcome Assessment, Health Care; D010043:Outcome and Process Assessment, Health Care; D012017:Referral and Consultation; D012042:Registries; D013503:Surgery Department, Hospital / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D014481:United States