JMIR Publications

ABSTRACT

Background:

The Smart Angel device is a home medical device and allows ambulatory surgery patients to monitor their health by taking their own blood pressure and oxygen levels and by answering a health questionnaire from home. Currently this device is a prototype being designed and no usability evaluation has been performed. This preventive device must necessarily be "usable" by patients with different profiles. In order to ensure patient safety when using the device, it is important to select patients to ensure their safety. For this, it would be interesting to know how to select or exclude them. However, the links between user characteristics and usability of home medical device remain unclear.

Objective:

The objective of this article is, therefore, to better understand the links between certain characteristics of potential patients (age, education, technophilia and health literacy) and usability (effectiveness, efficiency and satisfaction) defined by the ISO 9241-11.

Methods:

We conducted an experimental study involving thirty-six participants, investigating the effects of four patient characteristics (i.e. age, education, technophilia and health literacy) on usability measured in terms of effectiveness, efficiency, and satisfaction. A mixed-methods approach (subjective vs objective) using a variety of standard instruments was adopted (direct observation, video analysis, and questionnaires). Firstly, in order to help the participant project himself into the real use of the Smart Angel device, he watched a scenario in the form of a video. Secondly, the participants completed a questionnaire to show the extent of their health literacy level (Newest Vital Sign [NVS] and the Health Literacy Scale [HLS]) and then operated Smart Angel devices. Efficiency (ie, handling time) and effectiveness (ie, number of handling errors) measures were collected by video analysis. Satisfaction measures were collected by a questionnaire (system usability scale [SUS]). The qualitative observational data were coded using inductive analysis by two independent researchers specialized in cognitive psychology and cognitive ergonomics.

Results:

The results show a moderate and positive correlation between age and effectiveness (r = .359; P = .032) and efficiency (r = .357, P = .033). There is strong correlation between health literacy scored by NVS and effectiveness (r =.417; P = .011), efficiency (r = -.38, P = .022) and satisfaction (r = .45, P = .006). However, there is a weak correlation between technophilia and usability and no relationship between the level of education and usability.

Conclusions:

These results show that literacy level and age are two important factors to consider when selecting future users of the device to ensure patient safety. This study can also serve as an example to promote mixed methodologies in assessing the usability of medical devices that cannot be performed under real-world conditions.