title: Impact of case volume on outcomes of ureteroscopy for ureteral stones: the clinical research office of the endourological society ureteroscopy global study.
abstract: BACKGROUND
  The Clinical Research Office of the Endourological Society (CROES) undertook the Ureteroscopy Global Study to establish a prospective global database to examine the worldwide use of ureteroscopy (URS) and to determine factors affecting outcome.
  
  
  OBJECTIVE
  To investigate the influence of case volume on the outcomes of URS for ureteral stones.
  
  
  METHODS
  The URS Global Study collected prospective data on consecutive patients with urinary stones treated with URS at 114 centres worldwide for 1 yr. Centres were identified as low or high volume based on the median overall annual case volume.
  
  
  METHODS
  Pre- and intraoperative characteristics, and postoperative outcomes in patients at low- and high-volume centres were compared. The relationships between case volume and stone-free rate (SFR), stone burden, complications, and hospital stay were explored using multivariate regression analysis.
  
  
  CONCLUSIONS
  Across all centres, the median case volume was 67; 58 and 56 centres were designated as low volume and high volume, respectively. URS procedures at high-volume centres took significantly less time to conduct. Mean SFR was 91.9% and 86.3% at high- and low-volume centres, respectively (p<0.001); the adjusted probability of a stone-free outcome increased with increasing case volume (p<0.001). Patients treated at a high-volume centre were less likely to need retreatment, had shorter postoperative hospital stay, were less likely to be readmitted within 3 mo, and had fewer and less severe complications. At case volumes approximately >200, the probability of complications decreased with increasing case volume (p=0.02). The study is limited by the heterogeneity of participating centres and surgeons and the inclusion of patients treated by more than one approach.
  
  
  CONCLUSIONS
  In the treatment of ureteral stones with URS, high-volume centres achieve better outcomes than low-volume centres. Several outcome measures for URS improve with an increase in case volume.
  
  
  RESULTS
  Outcomes following treatment of ureteral stones by ureteroscopy (URS) were studied in a large group of patients at centres worldwide. The proportion of successful procedures (ie, those in which patients became stone free) increased as the annual volume of URS at a hospital increased. Hospital stays were shorter and postoperative complications were less likely at high-volume hospitals. We conclude that for URS, the best outcomes are seen in patients treated at high-volume hospitals.
authors.affiliation: Department of Urology, Vedanayagam Hospital and Postgraduate Institute, Tamilnadu, India.
authors.forename: Sangam V
authors.initials: SV
authors.lastname: Kandasami
authors.affiliation: Department of Urology, University Hospital of Heraklion, University of Crete, Medical School, Heraklion, Crete, Greece.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Mamoulakis
authors.affiliation: Department of Urology, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Ahmed R
authors.initials: AR
authors.lastname: El-Nahas
authors.affiliation: Division of Urology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Averch
authors.affiliation: Department of Urology, Pamukkale University Faculty of Medicine, Denizli, Turkey.
authors.forename: O Levent
authors.initials: OL
authors.lastname: Tuncay
authors.affiliation: Institute of Urology, Division of Tejnaksh Healthcare, Dhule, India.
authors.forename: Ashish
authors.initials: A
authors.lastname: Rawandale-Patil
authors.affiliation: Department of Urology, University of Foggia, Foggia, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Cormio
authors.affiliation: Department of Urology, AMC University Hospital, Amsterdam, The Netherlands. Electronic address: j.j.delarosette@amc.uva.nl.
authors.forename: Jean J
authors.initials: JJ
authors.lastname: de la Rosette
mesh_terms: D000328:Adult; D000368:Aged; D002983:Clinical Competence; D005260:Female; D061847:Hospitals, High-Volume / Q000592:standards / Q000706:statistics & numerical data*; D061846:Hospitals, Low-Volume / Q000592:standards / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D010359:Patient Readmission; D012044:Regression Analysis; D012955:Societies, Medical; D016896:Treatment Outcome; D014514:Ureteral Calculi / Q000628:therapy*; D018666:Ureteroscopy / Q000009:adverse effects / Q000592:standards / Q000706:statistics & numerical data*
keywords: Case volume; Clavien grade; Complications; Treatment outcome; Ureteral stones; Ureteroscopy