Rationale and design of a pragmatic randomized clinical trial assessing a smartphone-based digital health intervention in hypertension: The ELFIE-HYPERTENSION trial

BACKGROUND: Hypertension represents a major contributor to the global cardiovascular (CV) disease burden, yet it remains inadequately controlled largely due to poor treatment adherence. Emerging digital health technologies hold promise for improving blood pressure (BP) management and CV outcomes, but the lack of evidence, unavailability in most countries, and out-of-pocket costs have hindered the widespread use of these technologies in clinical practice. OBJECTIVES: To assess in a randomized controlled trial whether a digital health intervention (DHI) based on the free Elfie solution compared to usual care will reduce systolic blood pressure (SBP) in adults with uncontrolled hypertension (SBP ≥ 140 mmHg). METHODS: This is a pragmatic, open-label, randomized parallel arm, international, multicenter clinical trial. Adult individuals with hypertension are randomly assigned to usual care or a DHI based on the Elfie solution. Elfie offers a comprehensive set of features designed to enhance self-monitoring, adherence and education, complemented with a gamification feature to boost engagement. The primary outcome is office SBP measured at 6 months. Secondary outcomes include medication adherence, diastolic BP, BP control achievement, hypertension knowledge, self-care, health-related quality of life and process outcomes assessing app usage and engagement. CONCLUSIONS: The ELFIE-HYPERTENSION trial is an international multicenter pragmatic randomized clinical trial, investigating the effects of an innovative, free and scalable DHI to improve BP control. If proven effective, this intervention can be easily and widely implemented in the management of hypertension in a variety of clinical settings globally. TRIAL REGISTRATION NUMBER: The trial is registered at the Clinicaltrials.gov (NCT06242483).