Introduction: endoscopy plays an essential role in the management of patients with ulcerative colitis (UC), as it allows us to visualize and assess the severity of the disease. Different scores have been devised to standardize the findings because such assessments are not always objective.
Aims: the aim of this study was to assess the interobserver variability between the Index of Mayo Endoscopy (IME) and the Ulcerative Colitis Endoscopy Index of Severity (UCEIS), analyzing the severity of the endoscopic lesions in patients with UC. The secondary aim was to analyze if the cathartic preparation affected the degree of concordance amongst the endoscopists.
Material and methods: this was a single-cohort observational, comparative study in which a colonoscopy was performed in patients with UC, as the normal clinical practice. The results were classified according to the IME and the UCEIS by three endoscopic specialists. In order to assess the degree of interobserver correlation, the Kappa index for IME was used and the intraclass correlation coefficient was used for UCEIS.
Results: sixty-seven patients were included in the study. The average age was 51 (SD ± 16.7) and the average Mayo Clinic index was 3.07 (SD ± 2.54). The weighted Kappa index between endoscopists A and B for the IME was 0.8, 0.52 between A and C and 0.49 between B and C. The intraclass correlation coefficient for UCEIS was 0.922 between the three endoscopists (95 % CI: 0.832-0.959). A better interobserver correlation was found when the cathartic preparation was ≥ 8 based on the Boston Scale.
Conclusions: there was a higher correlation between the different endoscopists for the UCEIS than for the IME. Thus, this should be considered to be the best index to use in the clinical practice. A good cleansing preparation is important to improve the interobserver correlation.