Physical Activity During Radiotherapy for Lung Cancer – Evaluating Functionality and Practicability of a Reminder App in Healthy Volunteers

<h3>Background/Aim:</h3> Radiotherapy for lung cancer can lead to significant fatigue and a decrease in physical activity. An app that reminds the patients several times per day to perform a certain number of steps may be helpful in this respect. Such an app has just been developed. We aimed to investigated the functionality and practicability of the app in healthy volunteers before testing it in a prospective clinical trial. <h3>Patients and Methods:</h3> Thirty healthy volunteers participated in this prospective study (APPAREL-HV) and evaluated the app by affirming (=satisfaction) or negating ten statements in three sections related to functionality and practicability. If the satisfaction rate was &lt;80%, the app required further optimization. If it was &lt;60%, it appeared not useful. Subgroup analyses were performed for iPhone <i>vs</i>. Android users, German <i>vs</i>. Danish participants, and younger (&lt;50 years) <i>vs</i>. older (≥50 years) patients. <h3>Results:</h3> Overall satisfaction rates were 86.7% (two statements), 93.3-100% (two statements), and 90.0-100% (six statements) in the sections Download and installation, Navigation, and Content/functions, respectively. Android users were significantly less satisfied with Download and installation (50.0% <i>vs</i>. 95.8%, <i>p</i>=0.018). Otherwise, satisfaction rates were always ≥80%, and subgroup analyses showed no significant differences between the groups compared. <h3>Conclusion:</h3> According to the results of the APPAREL-HV, the current version of the app appeared not sufficiently useful for Android users and required significant improvement for this subgroup in the section Download and installation.