The Crohn's Disease-Health Index: Development and Evaluation of a Novel Outcome Measure.

Abstract

We sought to develop and validate the Crohn's Disease-Health Index (CD-HI), a disease-specific, patient-reported outcome measure that serially measures Crohn's disease (CD) symptomatic burden in adults with CD. As therapeutic interventions are tested among patients with CD, responsive outcome measures are needed to track disease progression and therapeutic gain during clinical trials. We conducted a national cross-sectional study of individuals with CD to identify the most prevalent and impactful symptoms of CD. The most relevant symptoms were included in the CD-HI. We used factor analysis, qualitative patient interviews, test-retest reliability evaluation, and known group validity testing to evaluate and optimize the CD-HI. The CD-HI contains 12 subscales that comprehensively measure CD burden using the patient's perspective. Fifteen adults with CD beta tested the CD-HI and found the instrument to be clear, easy to use, and relevant to them. Twenty-three adults with CD participated in an assessment of test-retest reliability, which indicated high reliability of individual questions, subscales, and the full instrument (intraclass correlation coefficient = 0.84 for the full instrument). The CD-HI and its subscales demonstrated a high internal consistency (Cronbach α = 0.98 for the full instrument). The CD-HI distinguished between groups of individuals with CD known to differ in disease severity. This research supports the use of the CD-HI as a valid, sensitive, reliable, and relevant patient-reported outcome to determine the multifactorial disease burden of those with CD, assess the relevance and merit of future CD therapies, and support drug labeling claims.