Introduction
Qualitative exit interviews provide key insights into patient experience and treatment expectations, which are particularly important in celiac disease (CeD) for which there are no current medications. Data relating to patients’ experiences are critical to understand what is considered a ‘meaningful change’ to patients when they participate in clinical trials. The objective of this study was to understand the clinical trial participants’ experience of CeD, their treatment expectations, and how they define meaningful changes in their symptoms as they exited from a phase 2 clinical trial.
Aims & Methods
Semi-structured telephone interviews of 60 minutes were conducted with eligible patients following a phase 2 double-blind, randomized, placebo-controlled trial in patients with moderate-to-severe CeD who maintained a gluten-free diet (GFD) for ≥ 12 months (NCT05353985).1 Patients could provide more than one response to some questions. Interviews were blinded to treatment assignment and were audio recorded, transcribed and coded guided by an a priori coding dictionary and a qualitative analysis plan. Transcript analysis was facilitated by ATLAS.ti 9 software. This study was approved by the relevant Institutional Review Boards as part of the phase 2 trial.
Results
Overall, 29 English-speaking patients from 15 clinical sites in the USA were interviewed. Three patients exited the trial early. Most participants were female (23/29, 79.3%), the mean age was 50.6 years, and the mean duration of disease before study enrollment was 6.9 years. These characteristics were similar to the full clinical trial population in which most patients were female (115/153, 75.2%), the mean age was 46 years, and the average time to CeD diagnosis was 9 years. The most commonly reported symptoms were abdominal pain (27/29, 93.1%), bloating (26/29, 89.7%), and diarrhea (24/29, 82.8%). The most bothersome symptom reported was diarrhea (12/29, 41.4%).
Participants most often stated that they were hoping for an improvement in their CeD (25/29, 86.2%) providing descriptions that included the desire to be able to eat without the worry of potential gluten contamination.
Participants were asked if a ‘symptom-free day’ (SFD) (defined as a day with no diarrhea, abdominal pain, bloating, or nausea) would be meaningful. All participants agreed that the concept of SFD is important, with the majority stating that an increase of 1–2 SFDs per week would be meaningful (20/28, 71.4%).
Participants were also asked what improvements on the PGIS (Patient Global Impression of Severity) and PGIC (Patient Global Impression of Change) scales would be meaningful to them (participants could provide multiple responses). The majority (31 responses) reported that a 2-point decrease in severity would represent a meaningful improvement, followed by 21 responses for a 1-point decrease in PGIS. Regarding PGIC, most patients (15/25, 60.0%) stated that ‘much improved’ would indicate a meaningful change, followed by ‘a little improved’ (6/25, 24.0%).
Conclusion
Despite adhering to a GFD, patients experienced frequent and bothersome symptoms, particularly abdominal pain, bloating, and diarrhea, prior to enrolling in the study. This study identified potential thresholds for meaningful improvement in weekly SFDs and PGIS and PGIC scales. These data are important to inform the design and interpretation of future CeD clinical trials.
References
1. ClinicalTrials.gov. Available from: https://clinicaltrials.gov/study/NCT05353985 (Accessed April 1, 2025).
Disclosure
SG, MA, and DAL are employees of Takeda Development Center Americas, Inc. and receive stock or stock options. NH and SM are employees of RTI Health Solutions which received funding from Takeda for participation in this study.
