Bowel cleansing quality evaluation in colon capsule endoscopy: what is the reference standard?

The diagnostic accuracy of colon capsule endoscopy (CCE) depends on a well-cleansed bowel. Evaluating the cleansing quality can be difficult with a substantial interobserver variation. Our primary aim was to establish a standard of agreement for bowel cleansing in CCE based on evaluations by expert readers. Then, we aimed to investigate the interobserver agreement on bowel cleansing. We conducted an interobserver agreement study on bowel cleansing quality. Readers with different experience levels in CCE and colonoscopy evaluated bowel cleansing quality on the Leighton-Rex scale and Colon Capsule CLEansing Assessment and Report (CC-CLEAR), respectively. All evaluations were reported on an image level. A total of 24 readers rated 500 images on each scale. An expert opinion-based agreement standard could be set for poor and excellent cleansing but not for the spectrum in between, as the experts agreed on only a limited number of images representing fair and good cleansing. The overall interobserver agreement on the Leighton-Rex full scale was good (intraclass correlation coefficient (ICC) 0.84, 95% CI (0.82-0.85)) and remained good when stratified by experience level. On the full CC-CLEAR scale, the overall agreement was moderate (ICC 0.62, 95% CI (0.59-0.65)) and remained so when stratified by experience level. The interobserver agreement was good for the Leighton-Rex scale and moderate for CC-CLEAR, irrespective of the reader's experience level. It was not possible to establish an expert-opinion standard of agreement for cleansing quality in CCE images. Dedicated training in using the scales may improve agreement and enable future algorithm calibration for artificial intelligence supported cleansing evaluation. All included images were derived from the CAREforCOLON 2015 trial (Registered with The Regional Health Research Ethics Committee (Registration number: S-20190100), the Danish data protection agency (Ref. 19/29858), and ClinicalTrials.gov (registration number: NCT04049357)).

© The Author(s), 2024.

Benedicte Schelde-Olesen has received honoraria and participated in advisory board meetings for Jinshan Ltd. Anastasios Koulaouzidis is shareholder of iCERV Ltd., has received consultancy fees and travel support from Jinshan Ltd., and has participated in advisory board meetings hosted by Dr FalkPharmaUK, Norgine, Jinshan, and ANKON. Emanuele Rondonotti has received honoraria from Fujifilm and consultancy fees from Medtronic. Xavier Dray has received lecture fees from Alfasigma, Bouchara, Recordati, Fujifilm, Medtronic, Norgine and Sandoz, has received consultancy fees from Norgine and Provepharma and is co-founder and shareholder of Augmented Endoscopy. Stefania Piccirelli has received a travel grant from AnX Robotica and honoraria from Malesci. Ulrik Deding, Ervin Toth, Konstantinos John Dabos, Abraham Eliakim, Cristina Carretero, Begoña González-Suárez, Thomas de Lange, Hanneke Beaumont, Uri Kopylov, Pierre Ellul, Enrique Pérez-Cuadrado-Robles, Alexander Robertson, Irene Stenfors, Alejandro Bojorquez, Gitte Grunnet Raabe, Reuma Margalit-Yehuda, Isabel Barba, Giulia Scardino, Salome Ouazana, Thomas Bjørsum-Meyer declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.