title: Higher surgeon and hospital volume improves long-term survival after radical cystectomy.
abstract: BACKGROUND
  Hospital and surgeon (provider) volume are associated with clinically significant outcomes for many types of surgery. Volume-outcome studies in patients undergoing radical cystectomy for bladder cancer have focused primarily on postoperative mortality. In the current study, the authors assessed the effect of cystectomy provider volume on long-term mortality.
  
  
  METHODS
  Using administrative databases, 2535 patients who underwent cystectomy by 199 surgeons in 90 hospitals in Ontario, Canada, between 1992 and 2004 were identified. The impact of provider volume on overall survival (OS) was assessed using Cox proportional hazards models fully adjusted for patient and tumor characteristics. Separate models were fit to examine the effect of surgeon and hospital volume. To confirm that the impact of volume on OS was independent of the effect of volume on short-term mortality, analyses were repeated excluding those patients experiencing postoperative deaths.
  
  
  RESULTS
  Of 2535 patients, 1796 (70.9%) died during the study period. Both higher hospital volume (hazards ratio [per unit increase in average annual number of procedures], 0.995; 95% confidence interval, 0.990-1.000 [P = .044]) and higher surgeon volume (hazards ratio, 0.984; 95% confidence interval, 0.975-0.994 [P = .002]) were found to be significantly associated with improved OS. Excluding post-operative deaths did not alter the results. Further analyses revealed that the benefit of high volume was attained by receiving care from either high-volume hospitals or high-volume surgeons.
  
  
  CONCLUSIONS
  High-volume providers were associated with improved long-term mortality rates compared with low-volume providers. This finding was independent of the effect of volume on perioperative mortality, suggesting that provider volume effects continue to manifest long after surgery.
authors.affiliation: Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Division of Urology, Department of Surgery, University Health Network, University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Girish S
authors.initials: GS
authors.lastname: Kulkarni
authors.forename: David R
authors.initials: DR
authors.lastname: Urbach
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
authors.forename: Neil E
authors.initials: NE
authors.lastname: Fleshner
authors.forename: Andreas
authors.initials: A
authors.lastname: Laupacis
mesh_terms: D000368:Aged; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D015653:Cystectomy / Q000379:methods / Q000401:mortality / Q000706:statistics & numerical data*; D005260:Female; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011785:Quality Assurance, Health Care; D016019:Survival Analysis; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery
keywords: bladder cancer; bladder neoplasm; cystectomy; outcomes; quality of health care