A Mixed-Methods Usability Validation of an Elderly-Centric Medication Reminder App

Abstract

Mobile health (mHealth) applications hold immense potential for elderly self-care, yet adoption remains low due to visually cluttered user interfaces that fail to accommodate agerelated declines in selective attention. To address this gap, this study validates a minimalist design framework grounded in Nilli Lavie’s Perceptual Load Theory (PLT).This study developed a medication reminder prototype incorporating five minimalist UI principles: partially flat design, high-contrast restricted colors, consistent typography, maximized negative space, and restricted features with camera-based character recognition. A moderated mixed-methods usability study with older participants (N=8, aged ≥60) evaluated seven tasks across five standard metrics. Quantitative results demonstrated excellent usability: a Laplace-adjusted task completion rate of 96.55% (90% CI = [91.78%, 100%]), a normalized geometric task execution time of 15.96 seconds (95% CI = [15.66s, 16.25s]), an overall post-task Single Ease Question (SEQ) score of 5.86, and an overall mHealth Application Usability Questionnaire (MAUQ) score of 5.91.Qualitative interviews confirmed that the simplified visual environment significantly reduced cognitive strain and enhanced legibility. These findings validate the minimalist-PLT framework as a highly usable, accessible design guideline for elderly-centric mHealth interfaces