title: High hospital and surgeon volume and its impact on overall survival after radical cystectomy among patients with bladder cancer in Quebec.
abstract: OBJECTIVE
  Previous studies reported improved outcomes for bladder cancer patients who had radical cystectomy (RC) performed by surgeons and hospitals with high annual RC volumes. The objective of this study was to determine the effect of high hospital and surgeon volume on overall survival after RC for bladder cancer in Quebec.
  
  
  METHODS
  We conducted a retrospective cohort study using data of patients who underwent RC for bladder cancer from 2000 to 2009. The cohort was obtained with the linkage of two health databases: the RAMQ database (data on medical services) and the ISQ database (vital status data). Hospital and surgeon volumes were defined as the average annual number of RC performed at an institution or by surgeon, respectively, during the study period. We considered high hospital and surgeon volume those found in the third and fourth quartiles of the distribution of hospital and surgeon volumes. The effect of high hospital and surgeon volume on survival was assessed by multivariate Cox proportional hazards models.
  
  
  RESULTS
  We analyzed a total of 2,778 patients who met inclusion criteria (75 % males). High hospital volume and surgeons were found to be significantly associated with improved overall survival (HR = 0.87, 95 % CI: 0.78-0.97 and HR = 0.81, 95 % CI: 0.71-0.91, respectively). The combined effect of high-volume hospital and high-volume surgeon decreased by 20 % the risk of long-term mortality (HR = 0.80, 95 % CI: 0.70-0.91).
  
  
  CONCLUSIONS
  Compared to low-volume providers, having RC for bladder cancer performed in high-volume hospitals or by high-volume surgeon was associated with improved overall survival.
authors.affiliation: Division of Cancer Epidemiology, Department of Oncology, McGill University, 546 Pine Avenue West, Montreal, QC, Canada, fabiano.santos@mcgill.ca.
authors.forename: Fabiano
authors.initials: F
authors.lastname: Santos
authors.forename: Ahmed S
authors.initials: AS
authors.lastname: Zakaria
authors.forename: Wassim
authors.initials: W
authors.lastname: Kassouf
authors.forename: Simon
authors.initials: S
authors.lastname: Tanguay
authors.forename: Armen
authors.initials: A
authors.lastname: Aprikian
mesh_terms: D000368:Aged; D015653:Cystectomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D061847:Hospitals, High-Volume / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D016016:Proportional Hazards Models; D011792:Quebec / Q000453:epidemiology; D012189:Retrospective Studies; D066231:Surgeons / Q000706:statistics & numerical data*; D015996:Survival Rate; D001749:Urinary Bladder Neoplasms / Q000401:mortality* / Q000601:surgery; D016526:Workload / Q000706:statistics & numerical data*