Concepts and Instruments for Patient-Reported Outcome Assessment in Celiac Disease: Literature Review and Experts’ Perspectives

Abstract

BackgroundIn diseases where there is a large subjective component, such as celiac disease (CD), patient reported-outcomes (PRO) endpoints are highly relevant. However, there is a gap in knowledge about which PRO endpoints and instruments should be used for clinical trials for treatment of celiac disease. ObjectivesTo identify patient-centered symptom, impact, and health-related quality of life (HRQoL) concepts in CD and relevant PRO instruments, and to gather expert input on concepts and instruments to inform selection of PRO endpoints for use in clinical trials of new CD treatments. MethodsA targeted literature review was conducted to identify symptom, impact, and HRQoL concepts, including those captured in PROs further reviewed against U.S. Food and Drug Administration standards for development and validation as endpoints. US and European clinicians, payers, and a patient advocate (n = 21) were interviewed to assess the identified concepts’ relative importance in measuring treatment benefit and to gauge the value of potential PROs as endpoints for market access/reimbursement. ResultsThirty-four published studies were identified: 27 elucidated patient-centered concepts and 7 detailed the development or validation of PRO instruments. The Celiac Disease Symptom Diary and Celiac Disease Patient Reported Outcome instrument were deemed most appropriate for use as endpoints; however, each had limitations related to conceptual coverage, evidence for measurement properties, and feasibility for use in clinical trials. Experts reported gastrointestinal symptoms as most important to treat, with extra-intestinal symptoms burdensome from the patient perspective as well. Payers emphasized measuring both frequency and severity of symptoms and targeting patients nonresponsive to the gluten-free diet for treatment. ConclusionsWith emerging treatment options for CD, further work is needed to operationalize PRO symptom endpoints that are meaningful to patients, valued by payers, and acceptable to regulators in demonstrating efficacy.