Background Smartphone applications and wearable devices are promising mobile health interventions for hypertension self‐management. However, most mobile health interventions fail to use contextual data, potentially diminishing their impact. The myBPmyLife Study is a just‐in‐time adaptive intervention designed to promote personalized self‐management for patients with hypertension. Methods and Results The study is a 6‐month prospective, randomized‐controlled, remotely administered trial. Participants were recruited from the University of Michigan Health in Ann Arbor, Michigan or the Hamilton Community Health Network, a federally qualified health center network in Flint, Michigan. Participants were randomized to a mobile application with a just‐in‐time adaptive intervention promoting physical activity and lower‐sodium food choices as well as weekly goal setting or usual care. The mobile study application encourages goal attainment through a central visualization displaying participants' progress toward their goals for physical activity and lower‐sodium food choices. Participants in both groups are followed for up for 6 months with a primary end point of change in systolic blood pressure. Exploratory analyses will examine the impact of notifications on step count and self‐reported lower‐sodium food choices. The study launched on December 9, 2021, with 484 participants enrolled as of March 31, 2023. Enrollment of participants was completed on July 3, 2023. After 6 months of follow‐up, it is expected that results will be available in the spring of 2024. Conclusions The myBPmyLife study is an innovative mobile health trial designed to evaluate the effects of a just‐in‐time adaptive intervention focused on improving physical activity and dietary sodium intake on blood pressure in diverse patients with hypertension. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT05154929.
Background: Achieving adequate blood pressure (BP) control is challenging for patients and clinicians. Digital hypertension management solutions that utilize push notifications to promote lifestyle management have been proposed as an approach, but their effectiveness remains unknown. Objective: This analysis was designed to interrogate the independent and short-term effects of push notifications, tailored to participant and environmental factors, on physical activity levels and sodium intake amongst individuals with hypertension. Methods: The myBPmyLife study was a 6-month randomized-controlled trial of participants with self-reported hypertension recruited from an academic medical center and federally qualified health centers. A core component of the intervention consisted of micro-randomized push notifications promoting lifestyle modifications that were randomly delivered at four daily time points and focused on physical activity and dietary sodium intake. Our primary outcome for this secondary analysis was step count 60 minutes after a physical activity notification and lower sodium food choices 24 hours after a dietary notification. This analysis focuses on the results of the micro-randomized trial and used a centered and weighted least squares method adapted for two or more treatments. Results: 298 participants were randomized to the intervention arm of whom 287 had data available for analysis. Participants’ mean age was 59.5 (SD 13.1) years, 138 (48.1%) were women, and 206 (71.8%) White. Participants were randomized at 187,517 time points over 6 months, which led to 0.96 (SD 0.86) push notifications/day divided between activity (50.4% [SD 0.4]) and dietary (49.8% [SD 0.4]) notifications. Activity notifications did not increase step count in the 60 minutes after a notification (Estimate 1.01, 95% CI 0.98 – 1.04; P = .40). Similarly, dietary notifications did not impact the number of lower sodium food choices in the subsequent 24 hours (Estimate 0.93, 95% CI 0.83 – 1.04; P = .23), but, in exploratory post-hoc analyses, did increase mobile application use by 95.5% (95% CI 1.81 – 2.10; P < .001), mobile application clicks/searches by 93.7% (95% CI 1.72 – 2.16 %; P < .001), and low sodium searches by 113.0% (95% CI 1.73 – 2.53; P < .001), all within 60-minutes. Conclusions: In patients with hypertension, push notifications did not impact short-term physical activity levels or dietary sodium intake though did improve intervention engagement. Clinical Trial: ClinicalTrials.gov NCT05154929; https://clinicaltrials.gov/study/NCT05154929