Abstract
BACKGROUND: People with HIV are aging rapidly and face accelerated aging-related comorbidities, including cardiovascular diseases and cognitive impairment, due to prolonged HIV-associated inflammation. Physical activity (PA) is a well-established intervention to mitigate these risks; yet, most older people with HIV remain sedentary. Despite considerable efforts to understand PA determinants and design interventions for people with HIV, outcomes have been suboptimal. OBJECTIVE: The overarching goal of this project is to use an ecological momentary assessment (EMA) approach to capture ecologically valid relationships between the personal experiences of older people with HIV and PA, as they engage in their normal daily activities. METHODS: This study will adopt a 2-phase mixed methods research design. The first phase focuses on developing the EMA questionnaire through in-depth interviews with older people with HIV to explore the relevance of candidate real-time predictors of PA, identified using the capacity, opportunity, motivation-behavioral framework and literature review, to their daily experiences. These interviews will validate and refine the constructs for the EMA survey. In phase 2, a 2-week EMA study will collect data from 70 sedentary older people with HIV through smartphone surveys (3 times per day) and Fitbit-measured step counts and moderate to vigorous intensity PA minutes. Multilevel modeling will be used to examine how these factors predict daily PA levels. RESULTS: This research project was funded in June 2024. To date, 13 eligible participants have completed the qualitative interviews. All participants agreed that the constructs of EMA survey are relevant to their PA experiences and acknowledged their time-varying nature. On the basis of the participants' input, the EMA survey has been finalized. CONCLUSIONS: By advancing the understanding of real-time determinants of PA, this study addresses a critical gap in the literature and offers a foundation for designing just-in-time adaptive interventions that provide tailored, context-specific support to enhance PA engagement and promote healthy aging among older people with HIV. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/81238.