A Mobile Health Intervention in Pulmonary Arterial Hypertension

A HIPPA compliant text messaging platform is linked to the Fitbit Application Program Interface. Real time activity data will be transmitted from the subject's smartphone to our mHealth platform via cellular network. Subjects will receive 3 texts/day in sync with their preferred morning, lunch, and evening leisure schedule (defined at enrollment). These texts will use personal, disease-specific, and provider information to deliver 2 types of messages customized to the current step count and sent in equal proportion. Messages are designed to facilitate self-awareness, reinforce step targets, and link physical activity with a reward or memorable cue.

The Fitbit Charge HR tri-axial accelerometer will be used to continuously gather data on physical activity, heart rate, and sleep. This device provides feedback in units of activity (steps, stairs climbed, activity time, and exercise time) and heart rate (per second when active, per 5 seconds when inactive). It has been validated against research devices in free-living conditions and is relatively inexpensive.