The usability of a smartphone-based fall risk health application for adult wheelchair users (Preprint)

BACKGROUND Individuals who use wheelchairs and scooters rarely undergo fall risk screening. Mobile health technology is a possible avenue to provide fall risk assessments. The promise of this approach is dependent upon its usability. OBJECTIVE To determine the usability of a fall risk mobile health application and identify key technology development insights for aging adults who use wheeled devices. METHODS Two rounds (n=5/round) of usability testing utilizing an iterative design-evaluation process were performed. Participants completed the custom-designed fall risk application, Steady-Wheels™. To quantify fall risk, the application led participants through 12 demographic questions and three progressively challenging seated balance tasks. Once completed, participants shared insights on the application’s usability through semi-structured interviews and the completion of the Systematic Usability Scale (SUS). Testing sessions were recorded and transcribed. Codes were identified within transcriptions to create themes. Average SUS scores were calculated for each round. RESULTS The first round of testing yielded two main themes: ease of use and flexibility of design. SUS scores ranged from 72.5 to 97.5 with a mean (SD) of 84.5 (11.4). After modifications were made, the second round of testing yielded two new themes: application layout and clarity of instruction. SUS scores improved in the second iteration and ranged from 87.5 to 97.5 with a mean of 91.9 (4.3). CONCLUSIONS The mobile health application, Steady-Wheels, has excellent usability and the potential to provide adult wheeled device users with an easy-to-use, remote fall risk assessment tool. Characteristics that promoted such usability were guided navigation, large text and radio buttons, clear and brief instructions accompanied by representative illustrations, and simple error recovery. Intuitive fall risk reporting was achieved through the presentation of a single number located on a color-coordinated continuum with low, medium, and high-risk delineations.