Correlation of Stool Frequency and Abdominal Pain Measures With Simple Endoscopic Score for Crohn’s Disease

Abstract

Background The Crohn’s Disease Activity Index (CDAI) has been criticized for being weakly correlated with bowel inflammation. We assessed correlation between Simple Endoscopic Score for Crohn’s Disease (SES-CD) and individual CDAI items stratified by disease location to better understand this relationship. Methods We pooled patient-level data from 3 placebo-controlled Crohn’s disease (CD) trials that tested adalimumab, upadacitinib, and risankizumab. Disease location was defined as ileum only, colon only, or ileocolonic based upon colonoscopy at study entry. Pearson correlation coefficients and linear regression assessed correlations between items of the CDAI and SES-CD. Results A total of 353 patients were included (20.7% ileal, 30.6% colonic, 48.7% ileocolonic disease). Crohn’s Disease Activity Index and SES-CD scores were moderately correlated (R = 0.33; P < 0.001). Among CDAI items, the strongest correlations with SES-CD were seen with very soft or liquid stool frequency (SF) and patient-reported outcome 2 (PRO2; which includes SF and abdominal pain score; both R = 0.36; P < 0.001); these correlations were numerically stronger in colonic disease (SF: R = 0.46; P < 0.001; PRO2: R = 0.44; P < 0.001) than in ileal disease (SF: R = 0.14; P = 0.23; PRO2: R = 0.21; P = 0.07), although a test for interaction was not significant. In adjusted linear regression models, the proportion of mucosa that was inflamed and the proportion of mucosa with ulceration were positively correlated, whereas the presence of strictures was inversely correlated with SF. Conclusions The SF item of the CDAI is moderately correlated with SES-CD and independently correlated with mucosal ulceration, inflammation, and strictures. Understanding why bowel inflammation as measured endoscopically does not correlate more strongly with patients’ symptoms could help develop scales that link CD pathology to patient experience.

A review on the current status and definitions of activity indices in inflammatory bowel disease: how to use indices for precise evaluation

“…Problems included in CDAI and alternative indices CDAI is a useful index, but it still has a number of problems [5,61,[66][67][68]. (1) There are evaluation items that may vary from subject to subject, such as general condition and abdominal pain, which may affect reliability and validity.…”

“…(7) Finally, correlations between endoscopic activity and biomarkers are poor. Therefore, the following several indices are attracting attention as alternative indices of CDAI [67,68].…”

“…PROs are attracting attention as alternatives to CDAI [ 67 , 68 ]. PROs provide clues as to what the patient feels as an important problem without the burden of undergoing examinations, leading to improvement in the HR-QoL of the patient [ 71 , 72 ].…”

Twenty‐five years of biologicals in IBD: What´s all the hype about?

“…Some experts have tried to optimize outcomes by increasing the stringency of the various endpoints but have actually decreased effect sizes [93]. With an R = 0.36 the correlation between stool frequency and abdominal pain score with an endoscopy score was statistically significant but poor [94]. The simple end‐of‐induction PROs strongly predict likelihood of clinical but not endoscopic remission after 1 year [95].…”

Systematic Literature Review and Meta-analysis: Real-World Mucosal Healing in Vedolizumab-Treated Patients with Crohn’s Disease

“…In addition, clinical indices like CDAI, long used to evaluate CD treatment efficacy, have been criticised for being less reliable as indicators of mucosal inflammation [8,20,21]. CDAI scores analysed from three placebocontrolled trials of adalimumab, upadacitinib, and risankizumab were only moderately correlated with mucosal inflammation of the bowel assessed endoscopically using SES-CD scoring [22].…”