Interobserver agreement of the Paris and simplified classifications of superficial colonic lesions: a Western study
Open Access
- 18 February 2021
- journal article
- research article
- Published by Georg Thieme Verlag KG in Endoscopy International Open
- Vol. 09 (03), E388-E394
- https://doi.org/10.1055/a-1352-3437
Abstract
Background and study aims The Paris classification of superficial colonic lesions has been widely adopted, but a simplified description that subgroups the shape into pedunculated, sessile/flat and depressed lesions has been proposed recently. The aim of this study was to evaluate the accuracy and inter-rater agreement among 13 Western endoscopists for the two classification systems. Methods Seventy video clips of superficial colonic lesions were classified according to the two classifications, and their size estimated. The interobserver agreement for each classification was assessed using both Cohen k and AC1 statistics. Accuracy was taken as the concordance between the standard morphology definition and that made by participants. Sensitivity analyses investigated agreement between trainees (T) and staff members (SM), simple or mixed lesions, distinct lesion phenotypes, and for laterally spreading tumors (LSTs). Results Overall, the interobserver agreement for the Paris classification was substantial (κ = 0.61; AC1 = 0.66), with 79.3 % accuracy. Between SM and T, the values were superimposable. For size estimation, the agreement was 0.48 by the κ-value, and 0.50 by AC1. For single or mixed lesions, κ-values were 0.60 and 0.43, respectively; corresponding AC1 values were 0.68 and 0.57. Evaluating the several different polyp subtypes separately, agreement differed significantly when analyzed by the k-statistics (0.08–0.12) or the AC1 statistics (0.59–0.71). Analyses of LSTs provided a κ-value of 0.50 and an AC1 score of 0.62, with 77.6 % accuracy. The simplified classification outperformed the Paris classification: κ = 0.68, AC1 = 0.82, accuracy = 91.6 %. Conclusions Agreement is often measured with Cohen’s κ, but we documented higher levels of agreement when analyzed with the AC1 statistic. The level of agreement was substantial for the Paris classification, and almost perfect for the simplified system. Received: 17 August 2020 Accepted: 09 December 2020 Publication Date: 19 February 2021 (online) © 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/) Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyThis publication has 30 references indexed in Scilit:
- NBI and NBI Combined with Magnifying ColonoscopyDiagnostic and Therapeutic Endoscopy, 2012
- Guidelines for Reporting Reliability and Agreement Studies (GRRAS) were proposedJournal of Clinical Epidemiology, 2011
- Clinicopathological differences of laterally spreading tumors of the colorectum according to gross appearanceEndoscopy, 2010
- Prevalence of nonpolypoid colorectal neoplasia: An Italian multicenter observational studyEndoscopy, 2010
- Nonpolypoid neoplastic lesions of the colorectal mucosaGastrointestinal Endoscopy, 2008
- Computing inter‐rater reliability and its variance in the presence of high agreementBritish Journal of Mathematical and Statistical Psychology, 2008
- Update on the Paris Classification of Superficial Neoplastic Lesions in the Digestive TractEndoscopy, 2005
- The Paris endoscopic classification of superficial neoplastic lesions: esophagus, stomach, and colon: November 30 to December 1, 2002Gastrointestinal Endoscopy, 2003
- Circumferential EMR of carcinoma arising in Barrett's esophagus: case reportGastrointestinal Endoscopy, 2003
- High agreement but low Kappa: I. the problems of two paradoxesJournal of Clinical Epidemiology, 1990