Older adults represent a rapidly growing segment of mobile health (mHealth) application users, yet the interaction modalities dominant in commercial health applications, including fine-gesture touch, small-target navigation, and high-density information layouts, are systematically misaligned with the perceptual, motor, and cognitive changes associated with ageing. This paper presents the Ageing-Adaptive mHealth Design Framework (AADF), a formal model that weights accessibility feature contributions using a Geriatric Usability Impact Score (GUIS) derived from age-stratified usability dimensions: visual acuity decline, motor precision loss, and working memory reduction. A controlled usability evaluation was conducted with 64 participants aged 60–85 across three prototype configurations: Baseline (BL, standard commercial interface), Partially Accessible (PA, WCAG 2.1 Level AA), and AADF-instrumented (AADF), across six standardised mHealth task types. AADF achieves a mean task completion rate (TCR) of 89.4% compared to 41.8% for BL across all tasks and age subgroups, representing a 47.6 percentage-point improvement. Voice interaction reduced vital-sign entry time by 52% for participants aged 75–85. Progressive font scaling reduced reading-error rates by 44% for participants with self-reported low vision. Three structural design patterns, Stepped Navigation, Persistent Context Anchors, and Modality-Fallback Sequences, are formalised and evaluated, demonstrating collectively that navigation-complexity reduction accounts for 38% of the total AADF TCR improvement. The paper argues that age-specific mHealth accessibility requires a design philosophy extending beyond WCAG compliance into geriatric interaction engineering.
Chintham et al. (Fri,) studied this question.