Evaluation der Benutzerfreundlichkeit einer Yoga-App für Patientinnen und Patienten mit axialer Spondyloarthropathie

Background: Axial spondyloarthritis (AS) is a chronic inflammatory rheumatic disease characterized by potentially disabling inflammation of the spine and adjacent joints. Regular exercise is a cornerstone of treatment. However, patients with AS currently have little support. YogiTherapy is an app developed to support patients with AS by providing instructions for yoga-based home exercise therapy. Objective: The aim of this study was to evaluate the acceptability and usability of the YogiTherapy app, which was specifically designed to support AS patients in performing yoga exercises independently and tracking their disease progression. The research focused on user-centred aspects such as accessibility, functionality and integration of the app into patient self-management. In addition, the study assessed the potential of the app to facilitate yogabased therapeutic interventions aimed at improving health behaviours, deepening disease understanding, and enhancing patient quality of life. By exploring the synergy between digital health applications and exercise therapies, this study provides valuable insights into innovative approaches to empowering patients with AS to improve self-management and disease coping. Methods: This cross-sectional study, conducted between May 2022 and June 2023 at the Department of Rheumatology and Immunology, University Hospital Erlangen, Germany, included 65 patients meeting the ASAS classification criteria for AS or axial involvement in psoriatic arthritis. Participants evaluated the usability and acceptance of the YogiTherapy app using the User Version of the Mobile Application Rating Scale (uMARS) and the Net Promoter Score (NPS) after the app introduction. Demographic data, app affinity, physical activity levels, and disease-specific indices (BASDAI, BASMI, BASFI) were collected through an online survey and medical records. Statistical analyses, including Wilcoxon Mann-Whitney rank sum tests, chi-square tests, and correlation analyses, were performed to assess app usability, acceptance, and their relationship to patient characteristics. All data were pseudo-anonymized for analysis. Results: A total of 65 patients with AS (33, 51% female; age: mean 43.3, SD 13.6 years) were included in the study from May 2022 to June 2023. Subsequently, the data were analyzed. Usability was rated moderate, with a mean uMARS of 3.35 (SD 0.47) points on a scale from 0 to 5. The highest-rated uMARS dimension was information (mean 3.88, SD 0.63), followed by functionality (mean 3.84, SD 0.87). Females reported a significantly higher uMARS total score than males (mean 3.47, SD 0.48 vs mean 3.23, SD 0.45; P=.03, Vargha and Delaney A [VDA] 0.66, 95% CI 0.53-0.77). The mean of the NPS was 6.23 (SD 2.64) points (on a scale from 0 to 10), based on 43% (26/65 non-promoters, 42% (25/65) indifferent, and 15% (9/65) 2 promoters. A total of 7% (5/65) of those surveyed did not answer the question. When applying the NPS formula, the result is –26%. The NPS showed a positive correlation with the usage of mobile apps (r=0.39; P=.02). uMARS functionality was significantly higher rated by patients younger than 41 years (mean 4.17, SD 0.55 vs mean 3.54, SD 1; P