A Systematic Review of Measurement of Endoscopic Disease Activity and Mucosal Healing in Crohn's Disease: Recommendations for Clinical Trial Design

Background: Crohn's disease (CD) is a chronic idiopathic inflammatory disorder of the gastrointestinal tract. Recently, mucosal healing has been proposed as a goal of therapy because clinical symptoms are subjective. Evaluative indices that measure endoscopic disease activity are required to define mucosal healing for clinical trials. The primary objective of this systematic review was to assess the existing evaluative indices that measure disease activity in CD and evaluate their role as outcome measures in clinical trials. Methods: A systematic literature review was performed using MEDLINE (Ovid), EMBASE (Ovid), PubMed, the Cochrane Library (CENTRAL), and DDW abstracts to identify randomized controlled trials and controlled clinical trials that used a relevant evaluative index from inception to February 2013. The data obtained from these trials were reviewed and summarized. Results: The initial literature searches identified 2300 citations. After duplicates were removed, 1454 studies remained. After application of the apriori inclusion and exclusion criteria, 109 articles were included and 3 were identified with handsearches. In total, 9 evaluative indices for CD were identified and reviewed. The Crohn's Disease Endoscopic Index of Severity (CDEIS) and the Simple Endoscopic Score in Crohn's Disease (SES-CD) are indices with the most extensively described operating properties. Conclusions: Both the endoscopic evaluative instrument selected and the definition chosen for mucosal healing affect the validity of assessing endoscopic disease activity during a clinical trial for CD. Currently, the CDEIS and SES-CD have the most data regarding operating properties; however, further validation is required.