Accuracy and Inter-Observer Agreement of the Nice and the Kudo Classifications of Superficial Colonic Lesions: A Comparative Study

Aims For superficial colonic lesions, the NICE and the Kudo classifications are used in the in vivo prediction of histology and as a guide to therapy. The NICE system derives information from unmagnified NBI endoscopic images. The Kudo one necessitates a magnification but, as this tool is not commonly available, it is applied also to characterize unmagnified pictures. To compare the diagnostic performances of the two classifications.

Methods We conducted a prospective comparison of the NICE versus the Kudo classification for the differential diagnosis of colonic polyps taking histology as the gold standard. The inter-observer agreement for both classifications among 11 colonoscopists was also evaluated. Short unmagnified NBI videoclips of 64 colonic polyps (hyperplastic, adenomatous and invasive cancer lesions) were sent twice to the participants. In the first round they classified the lesions according to the NICE classification; four months later, the same videos were assessed with the Kudo system. The diagnosis provided by the participants were grouped in non-neoplastic, non-invasive neoplasia, invasive neoplasia.

Results Overall, the diagnostic accuracy was 82 % (95 %CI: 79-85) with the NICE system, and 81 % (95 %CI: 78-84) with the Kudo one (ρ=0.78). The accuracy of the NICE classification for non-neoplastic lesions was greater compared with the Kudo’s (ρ=0.03). Sensitivity sub-analyses revealed a higher ability of the NICE in distinguishing between neoplastic vs. non-neoplastic lesions (ρ=0.01). By using both κ and AC1 statistics, the overall inter-rater agreement resulted comparable: 0.49 and 0.66 for the Kudo, and 0.56 and 0.67 for the NICE, respectively. The only difference in terms of agreement category was highlighted for non-neoplastic lesions employing the AC1 statistics (0.56 with Kudo vs. 0.74 with NICE).

Conclusions Although the NICE classification was significantly better than the Kudo’s in some specific sub-analyzes, the two systems (using non-magnified images) may be considered comparable.

Citation: Cocomazzi F, Gentile M, Perri F et al. eP174 ACCURACY AND INTER-OBSERVER AGREEMENT OF THE NICE AND THE KUDO CLASSIFICATIONS OF SUPERFICIAL COLONIC LESIONS: A COMPARATIVE STUDY. Endoscopy 2021; 53: S153.

Publication History

Article published online:
19 March 2021