title: Real-Time Characterization of Diminutive Colorectal Polyp Histology Using Narrow-Band Imaging: Implications for the Resect and Discard Strategy.
abstract: OBJECTIVE
  Narrow-band imaging (NBI) allows real-time histologic classification of colorectal polyps. We investigated whether endoscopists without prior training in NBI can achieve the following thresholds recommended by the American Society for Gastrointestinal Endoscopy: for diminutive colorectal polyps characterized with high confidence, a ≥90% negative predictive value for adenomas in the rectosigmoid and a ≥90% agreement in surveillance intervals.
  
  
  METHODS
  Twenty-six endoscopists from 2 tertiary care centers underwent standardized training in NBI interpretation. Endoscopists made real-time predictions of diminutive colorectal polyp histology and surveillance interval predictions based on NBI. Their performance was evaluated by comparing predicted with actual findings from histologic analysis. Multilevel logistic regression was used to assess predictors of performance. Cumulative summation analysis was used to characterize learning curves.
  
  
  RESULTS
  The endoscopists performed 1451 colonoscopies and made 3012 diminutive polyp predictions (74.3% high confidence) using NBI. They made 898 immediate post-procedure surveillance interval predictions. An additional 505 surveillance intervals were determined with histology input. The overall negative predictive value for high-confidence characterizations in the rectosigmoid was 94.7% (95% confidence interval: 92.6%-96.8%) and the surveillance interval agreement was 91.2% (95% confidence interval: 89.7%-92.7%). Overall, 97.0% of surveillance interval predictions would have brought patients back on time or early. High-confidence characterization was the strongest predictor of accuracy (odds ratio = 3.42; 95% confidence interval: 2.72-4.29; P < .001). Performance improved over time, however, according to cumulative summation analysis, only 7 participants (26.9%) identified adenomas with sufficient sensitivity such that further auditing is not required.
  
  
  CONCLUSIONS
  With standardized training, gastroenterologists without prior expertise in NBI were able to meet the negative predictive value and surveillance interval thresholds set forth by the American Society for Gastrointestinal Endoscopy. The majority of disagreement in surveillance interval brought patients back early. Performance improves with time, but most endoscopists will require ongoing auditing of performance. ClinicalTrials.gov ID NCT02441998.
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado. Electronic address: Swati.Patel@ucdenver.edu.
authors.forename: Swati G
authors.initials: SG
authors.lastname: Patel
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Philip
authors.initials: P
authors.lastname: Schoenfeld
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Hyungjin Myra
authors.initials: HM
authors.lastname: Kim
authors.affiliation: Gastroenterology of the Rockies, Boulder, Colorado.
authors.forename: Emily K
authors.initials: EK
authors.lastname: Ward
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Kansas Medical Center, Kansas City, Kansas.
authors.forename: Ajay
authors.initials: A
authors.lastname: Bansal
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Yeonil
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Hosford
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Aimee
authors.initials: A
authors.lastname: Myers
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Foster
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, Northwestern University, Chicago, Illinois.
authors.forename: Jenna
authors.initials: J
authors.lastname: Craft
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Samuel
authors.initials: S
authors.lastname: Shopinski
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Wilson
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Ahnen
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Kansas Medical Center, Kansas City, Kansas.
authors.forename: Amit
authors.initials: A
authors.lastname: Rastogi
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors.forename: Sachin
authors.initials: S
authors.lastname: Wani
mesh_terms: D018256:Adenomatous Polyps / Q000473:pathology* / Q000601:surgery; D002983:Clinical Competence; D003111:Colonic Polyps / Q000473:pathology* / Q000601:surgery; D003113:Colonoscopy / Q000193:education*; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D000068156:Formative Feedback; D006801:Humans; D059032:Learning Curve; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D062048:Narrow Band Imaging; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D013647:Task Performance and Analysis; D062606:Tertiary Care Centers; D014481:United States
keywords: Advanced Endoscopic Imaging; Colon Polyps; Colorectal Cancer; Colorectal Neoplasia