Key Predictors of Adherence to a Mobile Health App for Managing Chronic Spontaneous Urticaria

Background: Mobile health technologies may improve the management of chronic diseases, such as chronic spontaneous urticaria. However, effectiveness of mHealth tools largely depends on patient adherence, which can be influenced by various demographic, clinical, behavioural, psychosocial factors, and apps characteristics (appealing and simplicity of use). Understanding these adherence patterns is crucial for optimizing mHealth interventions. In this study, we aimed to assess adherence patterns associated to the use of CRUSE, a mHealth app designed for patients with CSU. Methods: We assessed users of the CRUSE app with self-reported CSU or suggested by a physician. For each user, we evaluated the number of days they completed the CRUSE daily monitoring questionnaire (app adherence) within the first 3 months after installation. We constructed univariable and multivariable ordered beta regression models to identify predictors of 3-month adherence to the app. Results: We analysed data from 2085 patients (66,114 days). Median adherence to the CRUSE app was of 22 days (24.4% of 90 days). In multivariable regression models, the variables more strongly associated with increased adherence to CRUSE included age (average increase = 0.16 percent points [pp] per additional year; 95% credible interval [CrI] = 0.08; 0.23 pp), male sex (average difference = 4.24 pp; 95% CrI = 1.77; 6.39 pp), being from a European country (average difference = 2.66 pp; 95% CrI = 0.59; 5.19 pp), and using monoclonal antibodies (average difference = 4.60 pp; 95% CrI = 2.26; 6.65 pp). Conclusions: Our findings suggest that age, male sex, residence in Europe, and the use of monoclonal antibodies are significant factors associated with increased adherence to the CRUSE app. These insights may help identify patient subgroups who would benefit most from mHealth support in managing CSU.