As the wearable technology market continues to expand in 2019, consumers worldwide are using their devices to help them track and improve their health. Given the surge in popularity, physicians are starting to take a closer look at how to incorporate the data collected by patients’ personal devices into their clinical workflow to provide better patient care.

One such physician is Karl A. Poterack, MD, FAMIA, medical director of applied clinical informatics at the Mayo Clinic. He notes that the healthcare market is inundated with wearable devices, with more than 400 different devices from 100 brands currently available. According to data from Futuresource Consulting, approximately 100 million wearable devices were sold worldwide in 2018, representing a growth rate of more than 18 percent from 2017. Poterack estimates that more than 50 percent of Americans use wearables to monitor their health in some capacity, including devices from Fitbit, Xiaomi, Apple, Garmin, and Samsung.

The most popular health wearables, usually a wristwatch or wristband, have multiple sensors: pedometers, accelerometers, gyroscopes, magnetometers, barometers, altimeters, GPS, and photoplethysmographs. The data is typically collected passively and continuously, including steps, energy, sleep, heart rate (HR), blood pressure, oxygen saturation, glucose, weight, and body mass index.

 

Vast pools of personal health data

With this wide variety of sensors, wearable manufacturers are collecting and analyzing massive amounts of data. Fitbit alone has gathered 7.5 billion nights of sleep data and 9 trillion minutes of HR data from 25.4 million active users in 87 countries, says Carolyn Walsh, vice president and head of sales and business development at Fitbit Health, which is based in San Francisco.

With access to aggregated health data collected from all parts of the world, the wearable device maker can provide useful population health snapshots. For example, Fitbit’s analysis of more than 100 billion hours of aggregated user data shows that resting HR decreases significantly after age 40 — and that the United States and Singapore have the highest resting heart rate.

While the data from wearables can empower patients to make healthy lifestyle changes, Poterack says that currently very little wearable device data is utilized clinically, as existing infrastructures do not facilitate the easy integration of patient data generated from wearables into EHRs.

However, he added that “wearables provide a tremendous volume of potentially useful physiologic data” for physicians. Because of that, the healthcare industry is looking at ways to address the existing systemic and attitudinal barriers to utilizing the data.

The industry is starting to recognize and acknowledge the considerations in obtaining, curating, storing, and retrieving data from wearable monitoring devices. Poterack says that the technical challenges of collecting and storing the data can be overcome as more scalable solutions emerge. As that happens, clinicians will be better equipped to find ways to analyze and make use of wearable device data to improve outcomes at both the individual and population level.

 

Chronic disease management

While many wearables on the market have overlapping functionality, some are designed for very targeted clinical use cases. Wearables that help with Type 2 diabetes management, including prescription-based continuous glucose monitoring (CGM) systems, are now available from several manufacturers. Examples include Dexcom’s G6 CGM and Abbott’s FreeStyle Libre system.

Devices that can track glucose levels day and night — without a finger-stick — and automatically relay data are poised to help patients with diabetes more easily detect patterns and trends, which can result in better diabetes management. The systems typically include a small embedded internal sensor, a reader or app that can communicate to the sensor, and software that generates shareable reports.

This category of wearables is coming to market in response to the rapid global increase in diabetes diagnoses and need for simple monitoring tools. Marc Taub, PhD, divisional vice president of product development at Abbott Laboratories, warns that the diabetes epidemic is “severe and worsening.” The World Health Organization predicts that by 2040, an estimated 642 million adults worldwide will have diabetes, up from 425 million people today with the disease.

Taub says that while these patients should monitor their glucose levels four times per day, “the reality is that because of the difficulty of finger prick tests and available self-monitoring options, patients only check levels on average 1.6 times per day, which can put them at risk for an adverse event.”

Abbott’s CGM wearable, FreeStyle Libre, uses a sensor typically embedded in a patient’s upper arm that takes glucose readings from the patient’s interstitial fluid (ISF). While blood glucose readings from a finger-stick tend to be about 5-10 minutes ahead of ISF readings, an ISF reading taken from the embedded sensor means the patient can frequently self-monitor, and most importantly, avoid finger-stick tests. The sensor filament is approximately 0.4 mm thick, and the patient swipes a reader over the sensor for a one-second scan. Each scan provides the wearer a current glucose reading, a trend arrow, and an eight-hour history.

The FreeStyle Libre 14-day reader is FDA approved and is only available with a prescription. Abbott estimates that most commercially insured patients will pay between $40 to $75 per month for the FreeStyle Libre 14-day sensors.