Usability and Acceptability Evaluation of a Digital Health Physical Activity Intervention among Older Family Caregivers of Patients with Heart Failure

Abstract Digital health physical activity (PA) programs have shown promise for improving the health and wellness of family caregivers (FCGs). However, their use among older adult caregivers remains underexplored. To address this gap, we developed TPA4You, a tailored digital health PA program that integrates videoconferencing with a health coach, a fitness tracker, and motivational messaging. The program is designed to support older caregivers, a population whose health and self-care needs are underserved by digital health interventions. This study evaluated the usability and acceptability of TPA4You among older FCGs of patients with heart failure. An iterative design approach guided by the Rapid Iterative Testing and Evaluation methodology was employed. Usability and acceptability were assessed through a two-phase, 1-week trial. Participant feedback from each phase informed iterative refinements to the TPA4You design. Eleven participants were enrolled (Phase 1, n = 7; Phase 2, n = 4), similar in age (68.3 ± 7 vs. 68.0 ± 7). Ten participants identified as non-Hispanic White. All Phase 1 participants were female, while Phase 2 included one male. Participants in both phases reported high perceived usefulness, satisfaction, and ease of use. Interviews on usability and acceptability revealed four common themes in Phases 1 and 2: (1) overall usability and usefulness; (2) supporting self-care and awareness of PA needs; (3) enhancing physical and mental health; and (4) design and features as facilitators and barriers to engagement. Findings demonstrate the feasibility, usability, and acceptability of TPA4You and provide guidance for optimizing its design for a future randomized controlled trial in a larger and more diverse population.