JMIR Publications

ABSTRACT

Background:

Fatigue is burdensome in advanced cancer. Wearable-informed mobile health (mHealth) apps may support monitoring and self-management, but evidence on usability and engagement in this population is limited.

Objective:

To evaluate the feasibility, usability, engagement, and patient experience of a wearable-informed mHealth app for fatigue self-management, and the reception of its exploratory digital fatigue score.

Methods:

In this 4-week, single-arm pilot study, adults with stage III-IV cancer according to the Union for International Cancer Control used the app and an activity tracker. We assessed enrollment, retention, and dropout reasons for feasibility, week-4 usability with the System Usability Scale (SUS) and the German version of the mHealth App Usability Questionnaire (GER-MAUQ), engagement through weekly self-reported use and satisfaction ratings and app usage logs, patient experience through optional weekly free-text responses, and reception of the fatigue score through study-specific ratings. Fatigue, health-related quality of life, and distress were exploratory outcomes assessed at baseline and weekly. Analyses included descriptive statistics, linear mixed models, and correlations.

Results:

Of 38 enrolled participants, 29 completed baseline and 23 completed week 4 (postbaseline retention 79.3%). Dropout respondents (n=5) mainly cited disease burden, and weekly free-text responses mainly described illness-related barriers. Mean SUS was 68.9 (SD 17.8), in the upper marginal range, and GER-MAUQ usefulness (median 4.29) was rated lower than ease of use (median 5.80, P<.001). Weekly active users decreased from 23 in week 1 to 19 in week 4. The fatigue score was used by 20 of 23 participants (87.0%), but its helpfulness was rated low (median 2.0 on a 1-5 scale).

Conclusions:

The app appeared feasible over 4 weeks in selected patients with advanced cancer, and dropout responses mainly cited illness burden rather than technical or privacy-related barriers. Usability was in the marginal to acceptable range, while usefulness was rated lower than ease of use. Engagement differed mainly in reach across features, and illness-related barriers and rigid daily planning limited use. The fatigue score attracted interest but needs clearer explanations, more actionable recommendations, and independent validation. Clinical outcomes were exploratory, and efficacy requires controlled evaluation.