Abstract
Objective information that can be passively obtained in an ambulatory setting could be potentially useful for determining appropriate care in blood pressure (BP) management. This study utilized digital medicine (DM) prototypes and telemetric data acquisition to directly confirm medication use and to assess habits of daily living in a hypertensive population. Thirty-seven patients (23 men age 62±9 years) used the system for 6 weeks. DM prototypes consisted of valsartan 80 mg or 160 mg placed in a gelatin hemicapsule with an excipient tablet as a "stopper," with a poppy seed-sized ingestible sensor (IS) made of foodstuff on its external surface and capable of creating a biogalvanic current on ingestion to alert a wearable sensor (WS) that was worn on the torso. Passive data collection included IS ingestion dates and times, daily step count, BP, and weight. Automatic short message service (SMS) reminders were sent whenever BP or weight values were not received. Passive detection of DM ingestion was 98% when compared with directly observed dosing. Mean taking and timing adherence rates were 90% and 83%, respectively, and the average step count at a pace of ≥60 steps per minute was 2.0±1.5 h/d. An automatic SMS was sent and 100% confirmed for 251 BP and 14 weight values that were not received. Mild and transient WS-related skin irritation was the most common device-related adverse event. There were no serious or unanticipated adverse events. Ninety percent of patients did not mind swallowing a DM capsule, and 75% had a positive overall experience with the system. Ambulatory evaluation of medication adherence and habits of daily living appear to be feasible and acceptable using DM and passive acquisition of telemetric data.