Abstract
BACKGROUND: Hypertension is a major public health problem. Despite existing treatment options, overall blood pressure control is still insufficient. Digital health interventions have the potential to improve treatment success. We developed liebria, an internet-based digital intervention accessible via smartphones and computers, designed to support the self-management of hypertension. METHODS: We tested the effectiveness of liebria in reducing systolic blood pressure and improving other relevant endpoints in adults with hypertension using a parallel randomized controlled trial design. Adults with hypertension (mean age 54.5 years, 47.1% male) were recruited via a German health insurance provider and randomized (1:1; concealed allocation; no blinding of participants) to receive liebria in addition to treatment as usual (n = 52), or treatment as usual alone (n=50). Primary outcome was systolic blood pressure after 3 months (T1). Secondary endpoints were diastolic blood pressure, pulse pressure, quality of life, medication adherence, and social and work-related functioning. RESULTS: The study's statistical power was limited due to a smaller sample size (N = 102) than the a priori target sample size (N=676). Intention-to-treat analyses showed an effect of liebria on systolic blood pressure (baseline-adjusted between-group difference -3.5 mmHg, 95% CI -7.13 to 0.13, p = .053, Cohen's d = 0.36). More participants in the intervention group (78.2% vs. 54.3% in the control group) showed reductions in systolic blood pressure (p = .076). Moreover, liebria had effects on social and work-related functioning. No effects emerged for diastolic blood pressure, pulse pressure, quality of life, or medication adherence. No adverse events or device effects were observed. CONCLUSIONS: The present study shows first promising results of liebria's effects on systolic blood pressure and social and work-related functioning. Future studies should aim to replicate effects in a larger sample to increase statistical power. TRIAL REGISTRATION: German Clinical Trials Register (DRKS00025871); https://drks.de/search/en/trial/DRKS00025871 ; date of registration: October 5, 2021.