Volume 145, Issue 5, Pages 987-995 (November 2013) Reliability and Initial Validation of the Ulcerative Colitis Endoscopic Index of Severity  Simon P.L. Travis, Dan Schnell, Piotr Krzeski, Maria T. Abreu, Douglas G. Altman, Jean–Frédéric Colombel, Brian G. Feagan, Stephen B. Hanauer, Gary R. Lichtenstein, Philippe R. Marteau, Walter Reinisch, Bruce E. Sands, Bruce R. Yacyshyn, Patrick Schnell, Christian A. Bernhardt, Jean–Yves Mary, William J. Sandborn  Gastroenterology  Volume 145, Issue 5, Pages 987-995 (November 2013) DOI: 10.1053/j.gastro.2013.07.024 Copyright © 2013 AGA Institute Terms and Conditions

Figure 1 Distribution of overall endoscopic severity assessed by a VAS ranging from 0 to 100. Gastroenterology 2013 145, 987-995DOI: (10.1053/j.gastro.2013.07.024) Copyright © 2013 AGA Institute Terms and Conditions

Figure 2 Power of differentiation. The figure relates the mean difference in overall severity between videos measured on the VAS (x-axis) to statistical significance (P ≤ .05) of the mean difference of UCEIS between videos (y-axis). When the mean difference in overall severity between 2 videos reached 20 units on the VAS, the mean difference in UCEIS between those 2 videos was statistically significant approximately 80% of the time and reached 90% when the mean difference was 25 units on the VAS. Gastroenterology 2013 145, 987-995DOI: (10.1053/j.gastro.2013.07.024) Copyright © 2013 AGA Institute Terms and Conditions