JMIR Publications

ABSTRACT

Background:

Parkinson’s disease (PD) is a neurodegenerative disorder with a variety of motor and nonmotor symptoms. Many of these symptoms can be monitored by digital solutions, including smartphone apps, wearable sensors, and camera systems. Usability of such systems is a key factor in long-term use, but not much is known about predictors of the successful use and preferable methods to assess usability in patients with PD (PwPD).

Objective:

This study tested methods to assess usability and determined prerequisites for successful use in PwPD.

Methods:

We performed comprehensive usability assessments with 18 PwPD utilizing a mixed-methods usability battery containing the System Usability Scale (SUS), rater-based evaluation of device-specific tasks and qualitative interviews. Each patient performed the usability battery with two of three randomly assigned devices: A tablet app, wearable sensors, and a camera system. The usability battery was administered at the beginning and at the end of a four-day testing period. Between usability batteries, the systems were used by the patients during three sessions of motor assessments (wearable sensors and camera system) and on the movement disorder ward (tablet app).

Results:

In this study, the rater-based evaluation of tasks discriminated best between the three eHealth solutions whereas conventional usability testing modalities like the SUS were not suitable to predict successful use of a device. Successful use was associated with different clinical characteristics for each system: eHealth literacy and cognitive function predicted successful use of the tablet app; better motor function and lower age correlated with the independent use of the camera system. Successful use of the wearable sensors was independent of clinical characteristics. Patients who were not able to use the devices well provided only few improvement suggestions in qualitative interviews.

Conclusions:

EHealth solutions should be developed with a specific set of patients in mind and subsequently tested in this cohort. It is unlikely that one solution will be able to serve all PwPD. Usability assessments should include rater-based evaluation of task performance, and there is a need to develop strategies to circumvent the underrepresentation of poorly performing patients in qualitative usability research.