OBJECTIVE:
Real-time assessment of gastrointestinal (GI) symptoms in irritable bowel syndrome (IBS) using the experience sampling method (ESM) is suggested as a more appropriate approach than currently used end-of-day or end-of-week reports. This psychometric evaluation study assesses the validity and reliability of a previously developed ESM-based patient-reported outcome measure (PROM) for real-time GI symptom assessment in IBS.
METHODS:
This multicenter validation study included 230 Rome IV IBS patients (80% female; mean age 41.2 years) in three European countries. Patients completed the electronic ESM-PROM (up to ten random moments daily, with a weekly minimum completion rate of 33%) and an end-of-day symptom diary for seven consecutive days. End-of-week questionnaires (GSRS-IBS, IBS-SSS, PHQ-9, and GAD-7) were completed at the end of the 7-day period.
RESULTS:
The ESM assessment had a mean completion rate of 71%. Strong and significant correlations (0.651-0.956) with moderately-to-good consistency (ICCs 0.580-0.779) were observed between ESM and end-of-day scores. However, end-of-day scores were significantly higher (Δ0.790-1.758, p<0.001) than mean daily ESM scores. Differences with end-of-week scores were more pronounced, with weaker correlations (Pearson's r 0.393-0.802). ESM-PROM exhibited moderate-to-good internal consistency (Cronbach’s α 0.585-0.887) across five symptom domains. First and second half-week scores demonstrated good-to-excellent consistency (ICCs 0.871-0.958).
CONCLUSIONS:
Psychometric evaluation demonstrated strong validity and reliability of the ESM-PROM for real-time GI symptom assessment in IBS. In addition, the ESM-PROM provides a precise and reliable ascertainment of individual symptom pattern and trigger interactions, without the bias of peak reporting when compared to retrospective methods. This highlights its potential as a valuable tool for personalized healthcare in monitoring disease course and treatment response in IBS patients.
