Usability of the Atomic (Active Teens Multiple Sclerosis) Mobile App to Increase Physical Activity in Pediatric Multiple Sclerosis

Background: Higher levels of physical activity (PA) are associated with improved fatigue, depression, and reduced disease activity in pediatric onset Multiple Sclerosis (POMS), yet youth with POMS are highly inactive. That problem requires intervention delivery platforms that overcome current environmental, social and psychological barriers to PA uptake in POMS. A mobile app platform may offer such a solution. 

Objectives: To evaluate the usability (ease of use, understanding, satisfaction and acceptability) of a prototype of a POMS PA mobile app. 

Methods: We tested the usability of a prototype app based on previously identified preferences of youth with POMS. In an initial in-lab usability session (N=5), we evaluated how well participants navigated the app and completed tasks. Other participants (N=5) downloaded the app and received a Fitbit to use at home for 4 weeks. We assessed app usage rates, number of interactions, Fitbit data integration and download capability.  Participants completed an 8-item acceptability e-scale, rated 0 to 5 (3=neutral and 5=positive response). Items evaluated ease of use and enjoyability of the app; understandability of module content; helpfulness in describing PA level and setting PA goals; program likability; acceptability of time to complete the app; and program satisfaction. An evaluation of how many weeks the youth would use the app was also included. 

Results: Ten youth (2 male, 8 females aged 10-17 years) participated in either in-lab or at-home usability sessions. Average ratings were: ease of use 3.4; module 4.4 and content 3.7 understandability; enjoyment 4.3; describing PA 3.7; goal setting 4.4; time to use the app 3.7; overall satisfaction 4; overall acceptability 32/40. 85% of the sample endorsed using the app for 6 weeks or longer. During the at-home sessions, participants averaged 8.5 interactions of ≥ 30 seconds and 3.1 minutes in the app per day. 100% of Fitbit activity files were downloaded. 

Conclusions: Usability testing of the prototype app demonstrated good acceptability and user engagement with few data errors.  User recommended adaptations to the app are underway in order to further enhance the usability of the app. Adaptations include: increased font size to address visual acuity problems; added direction to facilitate transition between app features; improved PA visualization by fixing Fitbit syncing errors; adjusted Avatar appearance; added game rewards; replacing module text with infographics and video clips to decrease in app time requirements and improve content understanding. Future steps include a planned trial to evaluate the feasibility and utility of implementing the enhanced app for promoting PA in POMS.