LowSalt4Life: A Mobile Application to Reduce Sodium Intake And Blood Pressure

The primary and secondary outcomes will be determined in months 1 & 2. Participants will continue for another 4 months and during that time data for exploratory measures will be collected.

During the first 2 months of the study, a micro-randomized trial (MRT) will be performed within the App+JITAI group (N=200). This MRT is designed to learn which push notification messages effectively prompt the user to interact with the appropriate content within the mobile application.

Inclusion criteria

• Diagnosed with essential hypertension (HTN) by a medical provider and are on stable doses of antihypertensive therapy for at least three months prior to enrollment as documented in the electronic health record (EHR) and confirmed by participant self-report.
• A smartphone with a compatible Apple or Android operating system installed and able to download and use LowSalt4Life app including accepting all permissions and willing to allow the mobile applications to send push notifications
• A valid email address
• Fluent in spoken and written English

Exclusion criteria

• Unstable symptoms or markedly elevated blood pressure (BP) at enrollment (defined as systolic BP>180 mmHg, diastolic BP>120 mmHg)
• Contraindication to a sodium restriction diet
• An estimated sodium intake less than 1,500mg per day
• Known secondary causes of HTN (e.g., adrenal insufficiency, pheochromocytoma)
• Estimated glomerular filtration rate (EGFR) <30 or end-stage renal disease on dialysis
• Heart failure
• Inability to use Withings devices (blood pressure cuff and scale) due to equipment limitations or contraindications
• Currently pregnant or intent to become pregnant during the study period