Development of a web-based ecological momentary assessment tool to measure day-to-day variability of the symptoms in patients with Sjögren's disease

Objectives To develop and validate a web-based ecological momentary assessment (EMA) tool to enhance symptoms monitoring among patients with Sj & ouml;gren's disease (SjD). Methods Consecutive adults with SjD were enrolled in this pilot observational study. Participants used the WebApp over a 3-month period, for the daily collection of individual EULAR Sj & ouml;gren's Syndrome Patient Reported Index (ESSPRI) scales and separate assessment of eyes and mouth dryness, using 0-10 numerical scales. Primary outcome was the measure of the interdaily variability of symptoms. Data collected through the WebApp were compared with those obtained with paper-based questionnaires administered during a final visit, using distinct approaches (predicted error, maximum negative error and maximum positive error). User experience was assessed using the System Usability Scale (SUS) score. Results Among the 45 participants, 41 (91.1%) were women. Median age was 57 years (IQR: 49-66). Daily variability of symptoms ranged between 0.5 and 0.8 points across the scales. Over the 3-month period, the predicted error ranged between -1.2 and -0.3 points of the numerical scales. The greatest differences were found for fatigue (-1.2 points (IQR: -2.3 to -0.2)) and ESSPRI score (-1.2 points (IQR: -1.7 to -0.3)). Over the last 2 weeks, the predicted error ranged between - 1.2 and 0.0 points. Maximum negative error ranged between -2.0 and -1.0 points, and maximum positive error between -0.3 and 0.0 points. Median SUS score was 90 (IQR: 85-95). Conclusion Our results demonstrate the usability and the relevance of our web-based EMA tool for capturing data that closely reflects daily experiences of patients with SjD.