The Diagnostic Performance for Colorectal Neoplasms Using Magnified Endoscopy Differs between Experts and Novice Endoscopists: A Post Hoc Analysis

Abstract

Introduction: Magnified endoscopy is difficult for novice endoscopists because it requires both knowledge and skill of endoscopic diagnosis. The aim of this study was to examine the diagnostic performance of novice endoscopists on determining the invasive depth of colorectal neoplasms and compare it with that of experts. Methods: The present study was conducted as a post hoc analysis. Thirty expert and 30 novice endoscopists who use magnifying endoscopy (narrow-band imaging [NBI] and pit pattern analysis) were recruited for the online survey. Novice endoscopist was defined as one who has <5 years of experience in magnifying endoscopy. Three outcomes were assessed: (a) diagnostic accuracy of both novice and expert endoscopists in determining the depth of invasion; (b) additional diagnostic accuracy of novice endoscopists in determining the depth of invasion with magnifying NBI or pit pattern compared with nonmagnifying white light imaging (WLI); (c) difference in confidence on diagnosis among each modality between novice and expert endoscopists. Results: The area under the curve (AUC) of expert endoscopists was significantly higher than that of novice endoscopists. The AUC of the pit pattern was significantly higher than that of WLI regardless of lesion characteristics as determined by novice endoscopists. The proportion of answers with high confidence was significantly higher with expert endoscopists than with novice endoscopists. Conclusions: Aside from learning basic diagnosis of colorectal neoplasms, magnifying endoscopy may have substantial clinical benefit for novice endoscopists.