JMIR Publications

ABSTRACT

Background:

The growing aging population has increased the need for technologies that support informal caregivers in home-based elderly care. Digital Twin (DT) systems offer promising capabilities, yet their effectiveness depends on usability, an aspect still insufficiently evaluated among caregivers.

Objective:

To assess the usability of an elderly-care DT system using a dual-method evaluation that integrates subjective and objective behavioral performance.

Methods:

Fifty caregivers participated in a usability assessment combining the system usability scale (SUS) and details system activity log analytics. Log-based measures included task completion, time on task, errors, and abandonment rate. A composite user engagement score (UES) was computed and analyzed for correlation and predictive association with SUS ratings. Engagement clusters were also explored.

Results:

Caregivers reported an excellent mean SUS score of 80.45. System logs showed a 94.08% task completion rate, 2.66% abandonment, and an average task duration of 89.16 seconds. UES demonstrated significant correlations with SUS ((r = 0.626, ρ = 0.552, P < .001) and significantly predicted usability in regression analysis (β = 52.94, R² = 0.392, P < .001). Engagement-based clustering identified high-, medium-, and low-tier user groups, each exhibiting distinct usability patterns.

Conclusions:

Integrating subjective usability ratings with objective behavioral metric provides a rigorous and comprehensive approach to evaluating DT systems for elderly care. The findings highlight strong usability of the system and offer actionable insights for refining caregiver-support technologies.