title: Reduced polyp detection as endoscopy shift progresses: experience with screening colonoscopy at a tertiary-care hospital.
abstract: OBJECTIVE
  To determine whether polyp detection rates are reduced as time progresses through half and full-day endoscopy shifts.
  
  
  BACKGROUND
  Polyp detection on colonoscopy may be reduced during colonoscopies performed later in the day.
  
  
  METHODS
  Retrospective analysis of screening colonoscopies performed by attending physicians only between August 2003 and August 2005 at University of North Carolina Hospitals. The primary outcome was detection of any polyp. The secondary outcome was adenoma detection. Both were assessed by time of day and shift type.
  
  
  RESULTS
  A total of 3421 eligible screening colonoscopies, performed by 20 attending gastroenterologists, were analyzed. Polyp detection rate for colonoscopies initiated before 9 AM was 48.6%, versus 34.0% for those initiated after 4:00 PM (P=0.04). On multivariate analysis, each hour of the day was associated with reduced odds of polyp detection [adjusted odds ratio (OR) 0.93, 95% confidence interval (CI) 0.89-0.98 for any polyp; adjusted OR: 0.94, 95% CI: 0.89-0.98 for adenoma]. When evaluated by physician shift, the odds of polyp detection were reduced in the last 1.5 hours compared with the first 1.5 hours of the shift, regardless of the length or timing of the shift (AM shift: OR: 0.63, 95% CI: 0.41-0.96; PM shift: OR: 0.79, 95% CI: 0.42-1.46; and full-day shift: OR: 0.67, 95% CI: 0.44-1.00).
  
  
  CONCLUSIONS
  Polyp detection by attending tertiary-care gastrointestinal physicians is reduced as time progresses during both half and full-day endoscopy shifts. These findings have implications for future quality improvement interventions.
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7080, USA. millie_long@med.unc.edu
authors.forename: Millie D
authors.initials: MD
authors.lastname: Long
authors.forename: Christopher
authors.initials: C
authors.lastname: Martin
authors.forename: Robert S
authors.initials: RS
authors.lastname: Sandler
authors.forename: Hans H
authors.initials: HH
authors.lastname: Herfarth
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Shaheen
authors.forename: Evan S
authors.initials: ES
authors.lastname: Dellon
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D002983:Clinical Competence; D003110:Colonic Neoplasms / Q000175:diagnosis; D003111:Colonic Polyps / Q000175:diagnosis*; D003113:Colonoscopy / Q000379:methods / Q000592:standards*; D006785:Hospitals, University / Q000706:statistics & numerical data*; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008505:Medical Staff, Hospital; D015999:Multivariate Analysis; D009657:North Carolina; D015588:Observer Variation; D011787:Quality of Health Care; D013997:Time Factors