title: Queue position in the endoscopic schedule impacts effectiveness of colonoscopy.
abstract: OBJECTIVE
  Endoscopist fatigue potentially impacts colonoscopy. Fatigue is difficult to quantitate, but polyp detection rates between non-fatigued and fatigued time periods could represent a surrogate marker. We assessed whether timing variables impacted polyp detection rates at a busy tertiary care endoscopy suite.
  
  
  METHODS
  Consecutive patients undergoing colonoscopy were retrospectively identified. Indications, clinical demographics, pre-procedural, and procedural variables were extracted from chart review; colonoscopy findings were determined from the procedure reports. Three separate timing variables were assessed as surrogate markers for endoscopist fatigue: morning vs. afternoon procedures, start times throughout the day, and queue position, a unique variable that takes into account the number of procedures performed before the colonoscopy of interest. Univariate and multivariate analyses were performed to determine whether timing variables and other clinical, pre-procedural, and procedural variables predicted polyp detection.
  
  
  RESULTS
  During the 4-month study period, 1,083 outpatient colonoscopy procedures (57.5±0.5 years, 59.5% female) were identified, performed by 28 endoscopists (mean 38.7 procedures/endoscopist), with a mean polyp detection rate of 0.851/colonoscopy. At least, one adenoma was detected in 297 procedures (27.4%). A 12.4% reduction in mean detected polyps was detected between morning and afternoon procedures (0.90±0.06 vs. 0.76±0.06, P=0.15). Using start time on a continuous scale, however, each elapsed hour in the day was associated with a 4.6% reduction in polyp detection (P=0.005). When queue position was assessed, a 5.4% reduction in polyp detection was noted with each increase in queue position (P=0.016). These results remained significant when controlled for each individual endoscopist.
  
  
  CONCLUSIONS
  Polyp detection rates decline as time passes during an endoscopist's schedule, potentially from endoscopist fatigue. Queue position may be a novel surrogate measure for operator fatigue.
authors: Division of Gastroenterology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
authors: Alexander
authors: A
authors: Lee
authors: John M
authors: JM
authors: Iskander
authors: Nitin
authors: N
authors: Gupta
authors: Brian B
authors: BB
authors: Borg
authors: Gary
authors: G
authors: Zuckerman
authors: Bhaskar
authors: B
authors: Banerjee
authors: C Prakash
authors: CP
authors: Gyawali
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001071:Appointments and Schedules; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003111:Colonic Polyps / Q000175:diagnosis*; D003113:Colonoscopy / Q000379:methods; D005221:Fatigue; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D011597:Psychomotor Performance; D013997:Time Factors; D016526:Workload