The Effect of an mHealth Self-Monitoring Intervention (MI-BP) on Blood Pressure Among Black Individuals With Uncontrolled Hypertension: Randomized Controlled Trial (Preprint)

Abstract

BACKGROUND Hypertension (HTN) is one of the most important cardiovascular disease risk factors and affects over 100 million American adults. HTN-related health inequities are abundant in Black communities as Blacks are more likely to utilize the emergency department (ED) for chronic disease-related ambulatory care, which is strongly linked to lower BP control, diminished awareness of HTN, and adverse cardiovascular events. To reduce HTN-related health disparities, we developed MI-BP, a culturally tailed multi-behavior mHealth intervention that targeted behaviors of blood pressure self-monitoring, physical activity, sodium intake, and medication adherence in Blacks with uncontrolled HTN who were recruited from ED and community-based settings. OBJECTIVE We sought to determine the effect of MI-BP on BP, as well as secondary outcomes of physical activity, sodium intake, and medication adherence, compared to enhanced usual care control at one-year follow-up. METHODS We conducted a one-year, two-group RCT of the MI-BP intervention compared to an enhanced usual care where participants received a blood pressure cuff. Participants were recruited from EDs and other community-based settings in Detroit, MI, where they were screened for initial eligibility and enrolled. Baseline data collection and randomization occurred about 2- and 4-weeks after enrollment to ensure participants had uncontrolled hypertension and were willing to participate. Data collection visits occurred at 13-, 26-, 39-, and 52-weeks. Outcomes of interest included BP (primary outcome), as well as physical activity, sodium intake, and medication adherence (secondary outcomes). RESULTS We consented and enrolled 869 participants in this study, yet ultimately randomized 162 participants. At one-year, compared to baseline, both groups demonstrated significant decreases in SBP (MI-BP = 22.5 mmHg decrease in average SBP, p < .0001; control group = 24.1 mmHg decrease, p < .0001), adjusted for age and sex, with no significant differences between groups (time-by-arm interaction p = .99). Similar patterns, where improvements were noted for both groups, yet no differences were found between groups, were demonstrated for diastolic BP, physical activity, sodium intake, and medication adherence. Large dropout rates were observed for both groups (about 60%). CONCLUSIONS Overall, participants randomized to both the enhanced usual care control and MI-BP conditions experienced significant improvements in blood pressure and other outcomes, however, differences between groups were not detected, speaking to the general benefit of proactive outreach and engagement focused on cardiometabolic risk reduction in urban dwelling, low-SES Black populations. High rates of dropout were found and are likely to be expected when working in similar populations. Future work is needed to better understand engagement with mHealth interventions, particularly in this population. CLINICALTRIAL ClinicalTrials.gov NCT02360293; http://clinicaltrials.gov/ct2/show/NCT02360293. International registered report identifier (irrid): RR1-10.2196/12601. INTERNATIONAL REGISTERED REPORT RR2-10.2196/12601