P047 The Crohn's Disease-Health Index (CD-HI): Development and Validation of a Novel, Disease-Specific Patient Reported Outcome Measure for Clinical Trials.

Abstract

In preparation for upcoming clinical trials involving patients with Crohn's disease (CD), we examine the validity, reliability and usability of the Crohn's Disease-Health Index (CD-HI). The CD-HI is a multifaceted, disease-specific patient reported outcome measure (PROM) designed to measure CD symptomatic disease burden during clinical trials. As promising therapeutic interventions are being tested among CD patients, there is a clear need for researchers to have access to a valid, sensitive, and reliable patient reported outcome tool to track disease burden. This research describes the development and validation of the CD-HI as an efficient mechanism to quantify how CD patients both feel and function. We conducted semi-structured, qualitative interviews with CD patients to identify potential symptoms of importance in CD. We then conducted a large, cross-sectional survey study with CD patients to identify the prevalence and importance of symptoms identified during the prior interviews. Symptom questions in the first version of the CD-HI were selected based on overall frequency and impact in a large population of CD patients, generalizability, and potential to respond to therapeutic intervention. Questions which measured a similar concept were grouped into subscales using factor analysis. The first version of the CD-HI was beta tested to explore the usability and relevance of the instrument to patients. We then performed test-retest reliability of each question and subscale. Lastly, we determined the internal consistency for each subscale and the overall instrument. The CD-HI is now finalized and available for use in upcoming clinical trials. Sixteen adults with CD participated in semi-structured qualitative interviews, providing 792 quotes regarding the symptomatic burden of CD. Four hundred and three adults with CD completed an online survey to determine the prevalence and relative importance of 148 patient identified symptoms. Questions were selected for the CD-HI based on their prevalence and relative importance to CD patients. Sixteen adults with CD participated in beta interview testing to address the usability and relevance of the instrument. Patients found the CD-HI to be clear, highly relevant, and easy to use. Test-retest reliability was conducted with twenty-three adults with CD, where participants completed the CD-HI at baseline and fourteen days later. One question was removed to optimize the overall reliability of the instrument. The final version of the CD-HI contains subscales that measure the following granular areas of CD health: 1) fatigue; 2) dietary restrictions; 3) gastrointestinal health; 4) sleep and daytime sleepiness; 5) bowel and bladder function; 6) emotional health; 7) joint health; 8) pain; 9) neck and back health; 10) activity participation; 11) social health; and 12) skin health. Total CD disease burden is measured using a weighted composite of these subscale scores. This research successfully demonstrates the ability of the CD-HI to report valid, reliable, and patient-relevant data as a disease-specific PROM. The CD-HI provides researchers and clinicians with an optimal mechanism to record relevant changes in CD health using the patient's perspective.