title: Is Prolonged Operation Time a Predictor for the Occurrence of Complications in Ureteroscopy?
abstract: OBJECTIVE
  To determine the impact of duration of ureteroscopy for urolithiasis on complication rates (CRs) of the procedure.
  
  
  METHODS
  A retrospective analysis of 2,010 patients, treated between 2006 and 2011, was done. The operation time (OT) and the occurrence of complications were compared.
  
  
  RESULTS
  The overall CR was 14.3% [298 complications, minor complications (Clavien I-II) 91.7%]. The median OT was 35 min [interquartile range (IQR) 20-61]. The OT differed significantly between those without complications [34 min (IQR 20-60)] and those with complications [45 min (IQR 25-76)] (p < 0.0001). The correlation between the OT and the occurrence of complications (r = -0.009648, p < 0.0001) was very weak and passed the level of significance (r = 0.2). The effect size was of minor relevance (Cohen's d = 0.27972).
  
  
  CONCLUSIONS
  Longer OT correlates significantly with a higher CR. The effect is however shown to be minor and the overall rate of complications, especially severe ones, is low.
authors.affiliation: Department of Urology, Asklepios Hospital Barmbek, Hamburg, Germany.
authors.forename: Sophie
authors.initials: S
authors.lastname: Knipper
authors.forename: Christian
authors.initials: C
authors.lastname: Tiburtius
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Gross
authors.forename: Christopher
authors.initials: C
authors.lastname: Netsch
mesh_terms: D000328:Adult; D000368:Aged; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D011183:Postoperative Complications; D012189:Retrospective Studies; D015607:Stents; D016896:Treatment Outcome; D018666:Ureteroscopy / Q000009:adverse effects* / Q000379:methods*; D052878:Urolithiasis / Q000601:surgery*; D014572:Urology / Q000379:methods