title: Narrow-band Imaging International Colorectal Endoscopic Classification to predict polyp histology: REDEFINE study (with videos).
abstract: OBJECTIVE
  The Narrow-band Imaging International Colorectal Endoscopic (NICE) Classification has been validated for differentiating hyperplastic from adenomatous polyps. This classification system was based on narrow-band imaging (NBI) technology, leaving uncertainty regarding its applicability to other systems. The aim of this study was to assess accuracy and reliability of histologic predictions for polyps <1 cm by applying the NICE classification to the Fujinon Spectral Imaging Color Enhancement (FICE) System.
  
  
  METHODS
  A video library of 55 polyps <1 cm histologically verified with FICE was prospectively created, including polyps that fulfilled inclusion criteria (morphology, size, histology) in consecutive colonoscopies. Six endoscopists with experience in electronic chromoendoscopy independently reviewed the polyp images, scored the polyps as adenomatous or hyperplastic, and assigned a level of confidence to the predictions. Twenty videos were reassessed at 6 months. The diagnostic performances of the endoscopists was calculated both combined and individually according to the histopathology of the polyps. A mixed-effect logistic regression model, in which polyps were considered as random effects, and polyp histology, confidence level, and readers were considered as fixed effects, was used. Results were expressed as odds ratios (ORs) with 95% confidence intervals (CIs).
  
  
  RESULTS
  Of the 55 polyps (mean size 4.6 mm), 29 (53%) were adenomas, and 26 (47%) were hyperplastic. Across all the readers and observations, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the curve (AUC) were 77%, 75%, 88%, 75%, 77%, and 0.82, respectively. Individual rater accuracy ranged from 66% to 96%, being <90% in 5 of 6 cases. Overall, 68.5% of predictions (226/330) were made with high confidence, although there was high variability (Fleiss kappa, 0.15; 95% CI, 0.08-0.22). Sensitivity, specificity, PPV, NPV, accuracy, and AUC for predictions made with high confidence were 81%, 80.5%, 80%, 77%, 82%, and 0.88 being significantly more accurate as compared with a low confidence of diagnosis (OR 2.4; 95% CI, 1.2-4.7). Regarding the performance of the individual NICE criteria, the odds of adenoma detection were 3.4 (95% CI, 1.8-6.3) and 4.0 (95% CI, 2.1-7.5) by using surface and vessels patterns alone, as compared with the color criterion. Interrater and intrarater agreement with the NICE was only moderate (interrater: Fleiss kappa, 0.51; 95% CI, 0.44-0.56; intrarater: kappa, 0.40; 95% CI, 0.20-0.60).
  
  
  CONCLUSIONS
  The application of the NICE classification to FICE resulted in suboptimal accuracy and only moderate interobserver agreement.
authors.affiliation: Digestive Endoscopy Unit, Istituto Clinico Humanitas Research Hospital, Milan, Italy; Digestive Endoscopy Unit, Istituto Clinico Humanitas University, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Repici
authors.affiliation: Digestive Endoscopy Unit, Istituto Clinico Humanitas Research Hospital, Milan, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Ciscato
authors.affiliation: Digestive Endoscopy Unit, Istituto Clinico Humanitas Research Hospital, Milan, Italy.
authors.forename: Loredana
authors.initials: L
authors.lastname: Correale
authors.affiliation: Department of Gastroenterology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Raf
authors.initials: R
authors.lastname: Bisschops
authors.affiliation: Departments of Gastroenterology and Endoscopy, Portsmouth Hospitals NHS trust, Portsmouth, United Kingdom.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Bhandari
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, University of Amsterdam, The Netherlands.
authors.forename: Evelien
authors.initials: E
authors.lastname: Dekker
authors.affiliation: Department of Gastroenterology and Interventional Endoscopy, Krankenhaus Barmherzige Brüder (St. John of God Hospital), Teaching Hospital of the University of Regensburg, Regensburg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Pech
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Radaelli
authors.affiliation: Digestive Endoscopy Unit, Istituto Clinico Humanitas Research Hospital, Milan, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Hassan
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000473:pathology; D018256:Adenomatous Polyps / Q000000981:diagnostic imaging* / Q000473:pathology; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000473:pathology; D003113:Colonoscopy; D006801:Humans; D006965:Hyperplasia; D016015:Logistic Models; D062048:Narrow Band Imaging; D016017:Odds Ratio; D012680:Sensitivity and Specificity; D047368:Tumor Burden; D014741:Video Recording