Wearable health-tracking devices like Fitbit and Apple Watch may help detect early signs of COVID-19 infections, as well as provide better insights into patients' long-term recovery from the disease, according to a paper published July 7 in JAMA Network Open.
The paper examines study results from the Digital Engagement and Tracking for Early Control and Treatment trial, spearheaded by researchers at the Scripps Research Translational Institute in La Jolla, Calif. More than 37,000 people enrolled in the study, which collected wearables data from March 25, 2020, to Jan. 24, 2021.
Participants downloaded the MyDataHelps research app and consented to share health data from their Fitbit, Apple Watch or other wearable device as well as report any illness symptoms to the app and results of any COVID-19 tests. The researchers found that when they combined wearable data with self-reported symptoms, they could detect COVID-19 cases more accurately than when they only analyzed symptoms.
After the results of the first trial, the Scripps researchers launched a new study focusing on a subset of 875 Fitbit wearers who reported having a fever, cough, body aches or other symptoms of respiratory illness and were tested for COVID-19, according to a July 7 New York Times report. Of the group, 234 tested positive for the virus, while the rest were believed to have other kinds of infections.
The study found that individuals from both groups slept more and walked less after getting sick while their resting heart rates were higher, according to the report. These changes were more pronounced in people with COVID-19, Jennifer Radin, MD, a Scripps epidemiologist leading the DETECT trial, told the Times.
The researchers also found that about nine days after participants with COVID-19 first began reporting symptoms, their heart rates dropped. After the drop, which was not observed in participants with other illnesses, their heart rates rose again and remained heightened for months. On average, it took 79 days for their resting heart rates to return to normal, compared to four days for those in the non-COVID-19 group.
The prolonged heart-rate elevation may be a sign that COVID-19 disrupts the autonomic nervous system, which manifests in symptoms such as heart palpitations and dizziness, according to the report. Participants' sleep and activity levels also returned to their baselines more slowly in individuals with COVID-19, compared to those with other ailments.
A limitation of the study, according to the researchers, was that they did not ask the participants to continue reporting their symptoms in the weeks and months after they first felt ill; however, the team plans to ask volunteers to do that in future research, according to the Times.