Efficacy of Tailored Messages for 28-Week Exercise Sustainability in People with HIV

Background: People with HIV (PWH) have increased risk for cardiovascular diseases and other age-related comorbidities. These risks can be reduced through moderate to vigorous physical activity (MVPA), but MVPA can be difficult to sustain over time. Purpose: We tested tailored text messages added to motivational interviewing (MI) to sustain MVPA among PWH. Messages were created based on Two Minds Theory and matched to daily survey responses about exercise barriers. Methods: 118 PWH ages > 50 were initially randomized to high-intensity interval training or continuous moderate-intensity exercise. After 16 weeks, 92 participants were re-randomized to receive either tailored messages plus MI, or educational control messages, for 12 weeks. Both groups completed daily barrier surveys and wore an ActiGraph monitor for 1 week/month. Results: PWH still receiving messages at 28 weeks maintained their MVPA, ending at M = 48.8 minutes per day (SD = 45.8, n = 22/29), compared to a decrease among PWH in the educational-control group, ending at M = 40.7 (SD = 24.6, n = 25/32), p = .01 for the group-by-time interaction. Findings were similar using both actigraphy and self-reported MVPA, and were robust to attrition based on intent-to-treat analysis. PWH in the tailored-messaging group also reported higher exercise self-efficacy and better perceived health over time, relative to those in the educational-control group. Conclusions: An automated tailored-messaging intervention led to sustained MVPA. Tailored messages were superior to non-tailored educational messages, and may help PWH maintain their long-term health. Exploratory analyses suggested these effects were additive to motivational interviewing.