Evaluation of a digital health intervention that promotes physical activity in older adults via the theoretical domains framework

Abstract Background Physical activity (PA) improves cardiovascular health in older adults. Digital health interventions can potentially promote PA but implementation among older adults, who are often less digitally savvy, may encounter user resistance. We adopted a theoretical domains framework (TDF), a implementation methodology, to evaluate their behaviors and attitudes towards mobile health applications (mHealth). Methods We studied community older adults whose PA and aerobic capacities were prospectively tracked alongside a mHealth application that charted PA habits, anthropometry, and vital signs. Interviewer-administered questionnaires collected information on mHealth satisfaction and TDF domains. Aerobic capacity was determined by peak oxygen uptake (VO₂) metrics. Results Among 100 participants we studied n=99 with complete data. The amount of time needed for the app and how good the app felt to use received the highest user satisfaction scores of 3.90 ± 0.985 and 3.88 ± 1.15, respectively; and having to remember to use the app, the lowest score of 3.09 ± 1.38. Users with high satisfaction scores were older (61.1 ± 7.33 vs 56.7 ± 7.71 years, p = 0.00395), and had higher PA frequency (p = 0.0247) and PA duration (p = 0.0430). User satisfaction scores correlated with TDF domains including "Emotions" (r = 0.594, p 0.001), "Social Influences" (r = 0.516, p 0.001), "Skills" (r = 0.411, p 0.001), "Social and Professional Roles and Identity" (r = 0.392, p 0.001), "Intentions" (r = 0.365, p 0.001), "Beliefs about Consequences" (r = 0.344, p 0.001) and "Behavioral Regulation" (r = 0.327, p 0.001) (Fig 1). Lower TDF scores were observed across seven TDF domains among those with low user satisfaction (Fig 2). Regressing for age and levels of PA, "behavioral regulation" (i.e., tracking progress against goals), "beliefs about consequences" (i.e., improving health and lifestyle), "skills" (i.e., ease of use) and "emotions" (i.e., feel good about own progress, feel worried about my PA) were associated with higher user satisfaction. Comparing participants with high vs. low VO₂ scores, the former rated "The introduction of how to use it was sufficient" higher (3.73 ± 1.03 vs. 3.07 ± 1.00, p = 0.0282) and "It has helped me to understand how I need to change my lifestyle habits" lower (3.48 ± 1.10 vs. 4.14 ± 0.864, p = 0.0348). At the end of follow-up, participants with high VO₂ scores rated "The introduction of how to use it was sufficient" higher (3.82 ± 0.92 vs. 2.92 ± 1.38, p = 0.00475) and rated "It has helped me set personal goals for my lifestyle habits in a way that I could not have done on my own" lower (3.53 ± 1.11 vs. 4.25 ± 0.866, p = 0.0354). Conclusion User satisfaction with a mHealth intervention was associated with TDF domains related to behavior regulation, consequences, skills, emotions―and VO₂. Designing digital PA intervention apps tailored to individual aerobic capacities of older adults and TDF considerations may be helpful.Correlation Heatmap: TDF & Sastisfaction Overall Domain Scores for TDF Domains