JMIR Publications

ABSTRACT

Background:

Mobile health is emerging as a ubiquitous paradigm for delivering healthcare interventions when self-management is feasible. However, interventions targeting older or frail subjects should account for their specific needs to improve usability and retention.

Objective:

In this paper we presented NutriA, a mobile application designed to counteract malnutrition in frail older subjects. We also discussed the results of a usability study conducted in a cohort of volunteers within the target age range.

Methods:

NutriA was designed as a self-instructional application built on the Moodle e-learning platform. It includes 24 weekly quizzes and associated informational items aimed at engaging users by sustaining attention and improving nutritional knowledge. A usability study was conducted with 35 healthy volunteers aged 65 years or older, who were able to use the app over a 4-week-period. At the end of the study, the Italian version of the standard System Usability Scale (SUS) and User Version of the Mobile App Rating Scale (uMARS) questionnaires were administered to assess NutriA usability.

Results:

Data from the SUS questionnaire yielded a median total score of 80/100 (IQR = 37.5) and a mean of 72.71/100 (SD = 21.28), indicating good perceived usability, with more than half of the participants rating the application as Acceptable (above the threshold of 68). The overall median uMARS score was 4.083 (IQR = 0.61875), with the Functionality and Information dimensions achieving the highest median score of 4.5 (with IQRs of 0.5 and 0.625, respectively).

Conclusions:

The usability study shows encouraging results. Some items, such as customizability, willingness to pay, and willingness to frequently use the app, received lower scores, and these findings will guide refinements to the final version of the app to be deployed with frail older subjects.