title: A systematic review and meta-analysis of the relationship between hospital/surgeon volume and outcome for radical cystectomy: an update for the ongoing debate.
abstract: BACKGROUND
  There is an ongoing debate about centralisation of radical cystectomy (RC) procedures.
  
  
  OBJECTIVE
  To conduct a systematic review of the literature on the volume-outcome relationship for RC for bladder cancer (BCa) with consideration for the methodologic quality of the available evidence and to perform a meta-analysis on the studies meeting predefined quality criteria.
  
  
  METHODS
  A systematic search was performed to identify all articles examining the effects of procedure volume on clinical outcome for cystectomy. Reviews, opinion articles, and surveys were excluded. All articles were critically appraised for methodologic quality and risk of bias. Meta-analysis was performed to calculate the overall effect of higher surgeon or hospital volume on patient outcome.
  
  
  RESULTS
  Ten studies of good methodologic quality were included for meta-analysis. Eight studies were based on administrative data, two studies on clinical data. The results showed a significant association between high-volume hospitals and low mortality. A meta-analysis of the seven studies on hospital mortality showed a pooled estimated effect of odds ratio (OR) 0.55 (range: 0.44-0.69). The result was moderate heterogeneity (I(2)=50). A large variation in cut-off points used was observed. Sensitivity analyses did not show different effects in any of the subgroup analyses. Also, no significant differences in effect sizes were observed for different cut-off points. The data were not suggestive for publication bias. One study showed a positive effect of hospital volume on survival (hazard ratio [HR]: 0.89; p=0.06). Two studies showed a beneficial effect of surgeon volume on mortality (OR: 0.55; OR: 0.64). Only one study on the impact of surgeon volume on survival was found; it showed no significant positive effect for higher volume (HR: 0.83; p=0.26).
  
  
  CONCLUSIONS
  Postoperative mortality after cystectomy is significantly inversely associated with high-volume providers. However, additional quality criteria, such as infrastructure and level of specialisation, should be formulated to direct centralisation initiatives. The Dutch Association of Urology in 2010 implemented a national quality of care (QoC) registration programme for all patients treated by surgery for muscle-invasive BCa, including multiple parameters defining QoC.
authors.affiliation: Department of Urology, University Medical Centre, Utrecht, The Netherlands. C.A.Goossens-Laan@umcutrecht.nl
authors.forename: Catharina A
authors.initials: CA
authors.lastname: Goossens-Laan
authors.forename: Gea A
authors.initials: GA
authors.lastname: Gooiker
authors.forename: Willem
authors.initials: W
authors.lastname: van Gijn
authors.forename: Piet N
authors.initials: PN
authors.lastname: Post
authors.forename: J L H Ruud
authors.initials: JL
authors.lastname: Bosch
authors.forename: Paul J M
authors.initials: PJ
authors.lastname: Kil
authors.forename: Michel W J M
authors.initials: MW
authors.lastname: Wouters
mesh_terms: D002983:Clinical Competence / Q000706:statistics & numerical data*; D015653:Cystectomy / Q000009:adverse effects* / Q000401:mortality; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D016017:Odds Ratio; D010043:Outcome and Process Assessment, Health Care / Q000706:statistics & numerical data*; D019984:Quality Indicators, Health Care / Q000706:statistics & numerical data*; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000401:mortality / Q000601:surgery*