JMIR Publications

ABSTRACT

Background:

Maintaining nutrition and exercise strategies after rehabilitation can be difficult for older people with existing malnutrition or limited mobility. A technical assistance system such as a health app could help to positively influence changes in dietary and exercise behavior and contribute to a sustainable improvement of nutrition and mobility status. Existing apps mostly do not provide a combination of nutrition and exercise content and have been evaluated with healthy individuals under 70 years of age, making transferability to vulnerable geriatric rehabilitation patients with functional limitations and estimated lower affinity for technology unlikely.

Objective:

This study aimed to design, test and iteratively optimize elements for an app (in the form of an e-coach) that should contribute to a sustainable improvement of nutrition and mobility status in older adults. It was intended to show that this part of the user-centered design (UCD) also works for older people undergoing inpatient rehabilitation.

Methods:

The iterative testing took place in a rehabilitation center with patients aged 65 and older. During testing, participants used an e-coach prototype with educational and interactive elements on nutrition and mobility as a one-time application test. They performed navigation and comprehension tasks and provided feedback on design aspects. Hints were given by the study team when needed and were documented. After testing, participants were asked to rate usability using the System Usability Scale (SUS).

Results:

Three iterative test phases (T1-T3) were conducted with a total of 49 participants (49% female, 77.8 ± 6.2 years). After each phase, improvements such as addition of explanatory notes on overview screens or use of consistent chart types were done. Using UCD in this specific target group allows the increase of SUS from 70.3 ± 16.7% (median 68.8%) at T1 to 78.3 ± 11.8 % (median 82.5 %) at T3. Fewer hints were needed for navigation tasks (T1: 14%; T2: 27%; T3: 18%) than for comprehension questions (T1: 28%; T2: 16%; T3: 23%). The total percentage of tasks that were not successfully completed despite help was 5.4%.

Conclusions:

One of the major adjustments was the extensive addition of explanatory sentences and terms instead of shorter keywords to make it easier to navigate to and comprehend the nutrition and exercise content. Thus, good usability (SUS 80th-84th percentile) was achieved through the iterative optimizations within the UCD. The usability over a longer period of time and possible effects on nutritional and physical activity behavior need to be evaluated in a further study where patients should be enabled to use the e-coach increasingly independently and thus gain access to content that can support long-term behavior change. Clinical Trial: none