title: Variability in flexible sigmoidoscopy performance among examiners in a screening trial.
abstract: OBJECTIVE
  The efficacy of flexible sigmoidoscopy (FSG) in reducing colorectal cancer mortality is being evaluated in randomized trials. In 2 European trials, wide variability across examiners in FSG performance was noted. We report on the performance of examiners in the US randomized trial: the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.
  
  
  METHODS
  Screening was performed at 10 geographically dispersed clinical centers. Patients with screens positive for a lesion or mass were referred to their private health care providers for endoscopic follow-up evaluation; lesions were not removed and a biopsy examination was not performed at screening. FSG performance among 64 examiners at these centers, each performing 100 or more baseline FSG examinations, with an aggregate of almost 50,000 examinations, was analyzed.
  
  
  RESULTS
  Screen-positivity results among examiners ranged from 9%-58%, with a coefficient of variation (CV) of 36%. CVs were 29% for distal polyp detection and 21% for distal adenoma detection. Inadequate rates ranged from 1%-27% (CV, 52%). Examiners with higher screen-positivity rates had higher false-positive rates, defined as a positive screen with no distal lesion found on endoscopic follow-up evaluation.
  
  
  CONCLUSIONS
  Considerable variability exists in the rates of positive screens and in polyp and adenoma detection rates among FSG examiners performing the procedures using a common protocol.
authors.affiliation: Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA. pp4f@nih.gov
authors.forename: Paul F
authors.initials: PF
authors.lastname: Pinsky
authors.forename: Robert E
authors.initials: RE
authors.lastname: Schoen
authors.forename: Joel L
authors.initials: JL
authors.lastname: Weissfeld
authors.forename: Barnett
authors.initials: B
authors.lastname: Kramer
authors.forename: Richard B
authors.initials: RB
authors.lastname: Hayes
authors.forename: Lance
authors.initials: L
authors.lastname: Yokochi
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000368:Aged; D003111:Colonic Polyps / Q000175:diagnosis; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000517:prevention & control*; D005189:False Positive Reactions; D005260:Female; D005762:Gastroenterology; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*; D008875:Middle Aged; D009722:Nurse Practitioners; D016032:Randomized Controlled Trials as Topic; D012737:Sex Factors; D012812:Sigmoidoscopy / Q000706:statistics & numerical data*; D012907:Smoking / Q000009:adverse effects; D014481:United States