First Experience With a Wireless System Incorporating Physiologic Assessments and Direct Confirmation of Digital Tablet Ingestions in Ambulatory Patients With Schizophrenia or Bipolar Disorder

Objective: To characterize the feasibility and safety of a wireless networked system incorporating physiologic assessments and direct confirmation of digital tablet ingestions in ambulatory patients with schizophrenia or bipolar disorder.

Method: In this 4-week observational study conducted between May 2010 and May 2011 at 2 US academic clinical study sites, 12 adults with bipolar disorder and 16 adults with schizophrenia (all diagnosed according to DSM-IV criteria) utilized a digital health feedback system (DHFS). All subjects were on a stable regimen of oral medication. The DHFS utilized a digital tablet, consisting of an ingestion sensor that was embedded in a tablet containing nonpharmacologic excipients, which subjects coingested with their regularly prescribed medication. The formulation of this digital tablet allowed ingestion sensor separation and activation by stomach fluids after ingestion, followed by communication of a unique identifying signal from the ingestion sensor to an adhesive sensor worn on the torso, which automatically logged the date and time of each digital tablet ingestion. The wearable sensor also collected physiologic measures including activity and heart rate. The primary study objective was to compare the accuracy of DHFS in confirming digital tablet ingestion versus a method of directly observed ingestion; secondary aims included characterization of adherence and physiologic measures longitudinally in these cohorts.

Results: 27 of 28 subjects (96%) completed the study. The mean adherence rate was 74% (95% CI, 64%-86%), and 67% (95% CI, 55%-79%) of doses were taken within 2 hours of the prescribed dosing time. Activity consisted of 847 to 15,930 steps daily, and sleep duration ranged from 3.2 to 15.2 hours daily. For individual subjects, mean sleep disruption, defined as the amount of brief arousals and postural changes during sleep events (eg, subject sitting up during the night), was as low as 5% and as high as 43% for the entire study period. The most common adverse event was minor skin irritation that occurred at the site of the wearable sensor in 5 subjects (18%), which did not lead to early discontinuation. No adverse events occurred due to the ingestion sensor. No subjects developed worsening of psychosis attributable to use of the DHFS. Of the 27 subjects who completed the study, 19 (70%) found the DHFS concept easy to understand, 21 (78%) said they would like to receive reminders on their cell phone if they forgot to take their medications, and 24 (89%) thought the DHFS could be useful to them.

Conclusions: The DHFS provided a novel means of confirming medication ingestion and tracking selected physiologic parameters, and it was generally well tolerated by patients.

Trial Registration: ClinicalTrials.gov identifier: NCT01804257

J Clin Psychiatry 2013;74(6):e533-e540

© Copyright 2013 Physicians Postgraduate Press, Inc.

Submitted: October 9, 2012; accepted March 25, 2013 (doi:10.4088/JCP.12m08222).

Corresponding author: Lorenzo A. DiCarlo, MD, 2600 Bridge Pkwy, Ste 101, Redwood City, CA 94065 (ldicarlo@proteusdh.com).