A Within-Subjects Usability Comparison of Check-in Interaction Methods for Older Adults

As China's population ages, more older adults live alone, leaving families uncertain whether they are safe each day. A check-in app, through which an older person sends a short "I'm fine" message, offers a simple answer, but most such apps rely on only a large button, and whether speaking or taking a photo would suit older users better remains unclear, since these actions differ in hand-control demands and context. This review synthesizes seven usability studies and scoping reviews of older adults' health, voice, and photo applications, addressing app design, daily check-in feasibility, usability measurement, and differing needs of older users and caregivers. The evidence shows tapping is more reliable than dragging, a coach-supported app package including a daily check-in proved feasible over one week, standard and simplified usability scales apply to this group, and voice and photo interactions show preliminary usability but remain untested for daily check-in. Three gaps remain: interaction methods are rarely compared head-to-head, photo-based check-in has not been tested, and few studies are set in China. This review outlines a within-subjects study comparing button, voice, and photo check-ins to identify the most usable method.