Supplementary Material for: Symptom Reporting in Patients with Primary Biliary Cholangitis: Higher Burden of Symptoms detection using an interactive App

Introduction: Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disease causing bile duct destruction and inflammation, impacting patient quality of life (QoL) due to variable symptoms. Digital symptom-tracker apps may improve patient care through enhanced monitoring. This feasibility study reassessed symptom burden in PBC patients using a tailored symptom-tracker app, focusing on its usability, effectiveness, and impact on management and QoL. Methods: Methods: Based on Kautz5 gUG "Symptomtracker", our app in REDCap allowed users to log PBC symptoms over four weeks, alongside medication use. Ethics approval and data security complied with German regulations. User feedback was incorporated for better usability. Symptom data were standardized, and R software was used for descriptive statistics and Chi-square tests. Results: From March 2023 to October 2024, 207 patients (184 female, 20 male) were enrolled, median age 51 years. Among 90 patients who completed the questionnaire, fatigue was most prevalent (87.8%), followed by joint pain (80%), concentration difficulties (74.4%), abdominal discomfort (70%), and sicca symptoms. Other common symptoms were leg cramps (50%) and swollen feet (40%); jaundice was rare (7.8%). Older patients, especially those aged 50–60, reported higher symptom burden, but Chi-square tests showed no significant differences across age or gender. Conclusion: Our study highlights a significant symptom burden in PBC, particularly fatigue and joint pain. While older patients reported more symptoms, no significant differences were observed by age or gender. The symptom-tracker app enhanced monitoring and patient engagement, showing the potential of digital tools in PBC management. Further research is needed to evaluate long-term impacts.