Digital health data provide insights into Long COVID

Through its Digital Health Program, RECOVER leveraged a special way of collecting data to learn more about Long COVID—while also providing an opportunity for study participants to monitor their own health data.

Digital health is a broad, rapidly growing area of research that uses technology to gather information about people’s health. Many digital health studies, like RECOVER’s Digital Health Program, use wearable devices made for consumers, such as fitness trackers and smart watches (often simply called wearables). When people use wearables, sensors collect information about their bodies and their bodies’ activities, such as information on sleep quality, physical activity, heart rate, and breathing.

The RECOVER Digital Health Program invited people who were participating in RECOVER’s observational studies to wear study-provided wearables on their wrists. These wearables provided health data both to study participants and to researchers. In total, nearly 4,500 people enrolled in the program and connected a wearable device to the study.

“Digital health data brings information that we’re not getting from lab results within the adult observational study, and the data can tell us about how Long COVID might be affecting peoples’ daily lives,” said Dr. Solveig Sieberts, principal investigator of RECOVER’s digital health data resource and Director of Digital Health at Sage Bionetworks. “With wearables, you can collect data every day, as opposed to clinic visits, which are less frequent and give us only a limited number of measures.” 

RECOVER is one of many studies that has incorporated digital health into its research. “Wearables are the future of monitoring health,” said RECOVER researcher Dr. Sairam Parthasarathy, adding that wearables help make research more convenient for participants because they do not have to go into the clinic for study visits.

Dr. Sieberts added that one of the benefits of using wearables in research is their ability to collect valuable information over time, which enables researchers to see patterns and variations. “We get such rich, deep data from wearables, and because we can collect information in a continuous manner, we can also see fluctuations over time,” she explained.

Other benefits of using wearables in research include improved flexibility for study participants and the ability to conduct studies more quickly and efficiently. Because each study participant is able to contribute so many data points, a smaller group of participants is required to prove a scientific point, explained Dr. Parthasarathy.

Continuous data collection from those who opted in to the Digital Health Program resulted in a combined total of more than 2.6 million days of activity and/or sleep data.

What digital health data can tell us about Long COVID

RECOVER researchers developed their Digital Health Program studies after considering the types of information that wearable devices can capture most reliably. They grouped this information into 2 categories: cardiorespiratory data (information related to the heart and breathing) and sleep data. The teams are currently developing 2 manuscripts—one focused on each group of data.

Cardiorespiratory data include information about:

• A person’s heart rate.
• Changes in a person’s heart rate (which can tell researchers information about symptoms that impact the autonomic nervous system, such as a heart rate that is too fast, or dizziness).
• A person’s blood oxygen saturation (a measure of the balance of oxygen in the blood).
• A person’s physical activity (such as how many steps they take).
• The intensity of a person’s physical activity. 

Sleep data include information about:

• How long a person spends sleeping.
• The quality of their sleep, such as how much REM sleep they get. (REM, or rapid eye movement, is a part of the sleep cycle that is important for physical and mental recovery.)

Both physical activity and sleep are important measures of overall health, explained Dr. Parthasarathy. They can also provide insights about Long COVID. “These measures can indicate Long COVID symptoms that may be prevalent and impacting a person’s quality of life,” he said. 

For example, if researchers see that a person is taking very few steps throughout the day, that person may be experiencing Long COVID symptoms such as fatigue or finding it challenging to complete daily activities. In the long term, decreased step count can have a negative impact on health, leading to problems such as weaker bones and muscles, or heart disease. 

“Wearables give us access to early signals, which we can then capitalize on to make things better for patients, such as better diagnosing them or monitoring their disease course or response to medications they’re taking,” Dr. Parthasarathy said.

Digital health work strengthened by collaboration

RECOVER’s digital health research is made possible by a team of experts from different fields who work together. Dr. Sieberts’s group leads the data processing, which means that they turn raw data into information that can be studied, check that the data are high quality, and share them with RECOVER researchers. 

The research team includes RECOVER researchers who specialize in different types of medicine. Dr. Jerry Krishnan, a RECOVER researcher and pulmonologist (a doctor who specializes in lung disorders), leads the team looking at cardiorespiratory data. Dr. Parthasarathy, an expert on sleep disorders, leads the team examining sleep data. 

The team also includes people with lived experience. Dr. Julia Moore Vogel, who is a researcher outside of RECOVER, also lives with Long COVID. She serves as the lead RECOVER Patient Representative and first author on the cardiorespiratory manuscript. “She has been really helpful in this effort to even ensure we are looking at these data in the most effective way and asking questions that matter to patients,” Dr. Krishnan said.

RECOVER Representatives, who are a part of the writing team for all RECOVER research publications, also contribute lived experience and expertise as they help to develop the Digital Health Program draft research papers.

Looking toward the future

Although RECOVER’s Digital Health Program recently closed and has completed data collection, study participants can continue tracking their health data on their own.

There is much for researchers to learn from the data collected—even beyond the findings of the 2 papers currently being developed. All digital health data from adult participants that can be studied will be made available to other researchers through the BioData Catalyst®, an online database where researchers can find, share, and study medical research data. 

Dr. Sieberts suggested that future RECOVER research might explore how digital health data can look different among people with different symptom patterns and Long COVID presentations.

“We are scratching the tip of the iceberg (with these initial studies),” said Dr. Parthasarathy. “There is more work to be done, and findings from our Long COVID data could also be scalable to other chronic medical conditions.”