Smartwatches can track COVID-19 symptoms, study finds
University of Michigan researchers found that new signals embedded in heart rate indicated when individuals were infected with COVID-19 and how ill they became.
If a COVID-19 infection develops, a wearable device may eventually be able to clue you in. A study at the University of Michigan found that a smartwatch can monitor how symptoms progress.
The study evaluated the effects of COVID-19 with various factors derived from heart-rate data. This method also could be employed to detect other diseases, such as influenza and the common cold, at home or when medical resources are limited, such as during a pandemic or in developing countries.
Tracking students and medical interns across the country, the University of Michigan researchers found that new signals embedded in heart rate indicated when individuals were infected with COVID-19 and how ill they became.
For instance, they discovered that individuals with COVID-19 experienced an increase in heart rate per step after the onset of their symptoms. Meanwhile, people who reported a cough as one of their COVID-19 symptoms had a much more elevated heart rate per step than those without a cough.
“We previously developed a variety of algorithms to analyze data from wearable devices. So, when the COVID-19 pandemic hit, it was only natural to apply some of these algorithms to see if we can get a better understanding of disease progression,” says Caleb Mayer, a doctoral student in mathematics at the University of Michigan and a co-first author of the study.
People may not internally sense COVID-19’s direct impact on the heart, but “heart rate is a vital sign that gives a picture of overall health," says Daniel Forger, a University of Michigan professor.
Millions of people are tracking their heart rate through wearable devices. This information is already generating a tremendous amount of data for researchers to analyze, says co-author Daniel Forger, professor of mathematics and research professor of computational medicine and bioinformatics at the University of Michigan.
“Heart rate is affected by many different physiological signals,” Forger explains. “For instance, if your lungs aren’t functioning properly, your heart may need to beat faster to meet metabolic demands. Your heart rate has a natural daily rhythm governed by internal biological clocks.” While people may not internally sense COVID-19’s direct impact on the heart, he adds that “heart rate is a vital sign that gives a picture of overall health.”
Among the total of 2,164 participants who enrolled in the student study, 72 undergraduate and graduate students contracted COVID-19, providing wearable data from 50 days before symptom onset to 14 days after. The researchers also analyzed this type of data for 43 medical interns from the Intern Health Study by the Michigan Neuroscience Institute and 29 individuals (who are not affiliated with the university) from the publicly available dataset.
Participants could wear the device on either wrist. They also documented their COVID-19 symptoms, such as fever, shortness of breath, cough, runny nose, vomiting, diarrhea, body aches, loss of taste, loss of smell, and sore throat.
Experts not involved in the study found the research to be productive. “This work is pioneering and reveals exciting new insights into the many important ways that we can derive clinically significant information about disease progression from consumer-grade wearable devices,” says Lisa A. Marsch, director of the Center for Technology and Behavioral Health and a professor in the Geisel School of Medicine at Dartmouth College. “Heart-rate data are among the highest-quality data that can be obtained via wearables.”
Beyond the heart, she adds, “Wearable devices are providing novel insights into individuals’ physiology and behavior in many health domains.” In particular, “this study beautifully illustrates how digital-health methodologies can markedly enhance our understanding of differences in individuals’ experience with disease and health.”
Previous studies had demonstrated that COVID-19 affects cardiovascular functions. Capitalizing on this knowledge, the University of Michigan endeavor took “a giant step forward,” says Gisele Oda, a researcher at the Institute of Biosciences at the University of Sao Paulo in Brazil and an expert in chronobiology—the science of biological rhythms. She commends the researchers for developing a complex algorithm that “could extract useful information beyond the established knowledge that heart rate increases and becomes more irregular in COVID patients.”
Wearable devices open the possibility of obtaining large-scale, long, continuous, and real-time heart-rate data on people performing everyday activities or while sleeping. “Importantly, the conceptual basis of this algorithm put circadian rhythms at the center stage,” Oda says, referring to the physical, mental, and behavioral changes that follow a 24-hour cycle. “What we knew before was often based on short-time heart rate measured at any time of day,” she adds, while noting that heart rate varies between day and night and also changes with activity.
However, without comparison to a control group of people having the common flu, it is difficult to determine if the heart-rate signals are unique to COVID-19 or also occur with other illnesses, says John Torous, an assistant professor of psychiatry at Harvard Medical School who has researched wearable devices. In addition, he points to recent data showing that many wearables, which work by beaming light through the skin, may be less accurate in people with darker skin due to variations in light absorption.
While the results sound interesting, they lack the level of conclusive evidence that would be needed to transform how physicians care for patients. “But it is a good step in learning more about what these wearables can tell us,” says Torous, who is also director of digital psychiatry at Beth Israel Deaconess Medical Center, a Harvard affiliate, in Boston. A follow-up step would entail replicating the results in a different pool of people to “help us realize the full value of this work.”
It is important to note that this research was conducted in university settings during the early phases of the pandemic, with remote learning in full swing amid strict isolation and quarantine mandates in effect. The findings demonstrate that physiological monitoring can be performed using consumer-grade wearable sensors, allowing research to continue without in-person contact, says Sung Won Choi, a professor of pediatrics at the University of Michigan who is principal investigator of the student study.
“The worldwide COVID-19 pandemic interrupted a lot of activities that relied on face-to-face interactions, including clinical research,” Choi says. “Mobile technology proved to be tremendously beneficial during that time, because it allowed us to collect detailed physiological data from research participants remotely over an entire semester.” In fact, the researchers did not have any in-person contact with the students involved in the study. “Everything was done virtually," Choi explains. "Importantly, their willingness to participate in research and share data during this historical time, combined with the capacity of secure cloud storage and novel mathematical analytics, enabled our research teams to identify unique patterns in heart-rate data associated with COVID-19.”
Nicole Gularte in Feb 2019 at her three-month follow up visit after her successful CAR T-cell therapy last fall at Penn.
[Editor's Note: This is the final video of a five-part series titled "The Future Is Now: The Revolutionary Power of Stem Cell Research." Produced in partnership with the Regenerative Medicine Foundation, and filmed at the annual 2019 World Stem Cell Summit, this series illustrates how stem cell research will profoundly impact human life.]
Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.
The Troubling Reason I Obsessively Researched My Pregnancy
A pregnant woman in her third trimester.
At the end of my second trimester of pregnancy, I answered a call from an unknown number.
To be pregnant is to exist on a never-ending receiving line of advice, whether we want it or not.
"I know your due date is approaching," said a stranger at the other end of the line, completely freaking me out. She identified herself as being from Natera, a company that my doctor had used for genetic testing I had consented to months ago.
"Excuse me?" I said.
"Have you considered cord-blood banking?" she said.
"No, I'm not doing that," I said. I had read enough about cord-blood banking, the process of saving stem cell-containing blood from your baby's umbilical cord, to understand that my family was in the vast majority of those that would with extremely high likelihood derive no medical benefit from it. Of course, in the societally sanctioned spending spree that accompanies new parenthood, plenty of companies are happy to charge anyone hundreds if not thousands of dollars plus annual storage fees to collect and manage your cord blood.
"Why not? Have you considered all the bene—"
"I'm not doing it and I don't want to explain my decision," I said before hanging up. I would later learn I neglected to check a miniscule box on my testing consent forms at the doctor to opt out of solicitations. Still, I was angry that I was being telemarketed unnecessary and costly medical services by someone who had been trained to immediately call my judgment into question. I was annoyed that my doctor's office would allow such intrusions at all. When I asked my OB about it at my next visit, she told me there's no way Natera would have gotten my information from them. Apparently even she didn't realize what was on those forms.
The incident with Natera did nothing to heighten my trust of the medical establishment during my pregnancy. I was hardly alone. Almost every mom I knew had expressed a similar sentiment.
"I don't trust doctors," read the text of a loved one when I told her I would probably get an epidural after my doctor recommended getting one because, she said, it can help relax the pelvic muscles during labor. But this friend, a highly educated woman who had had done her research and had two unmedicated births, believed firmly otherwise. "Look it up," she said. Thus commenced more of the furious Googling I found myself doing multiple times a day since deciding I wanted to become pregnant.
To be pregnant is to exist on a never-ending receiving line of advice, whether we want it or not. Information presents to us from Google's never-out-of-reach search bar, friends and family eager to use our pregnancies as an excuse to recall their own, and the doctor's office, where the wisdom of medical professionals neatly comingles with brochures and free samples from myriad companies that would really, really like our business as new moms. Separating the "good" advice from the rest is a Herculean task that many pregnant women manage only with vigorous fact-finding missions of their own.
The medical community in America is poorly equipped to help women navigate the enormous pressures that come with birth and transitioning to motherhood.
Doing my research during pregnancy felt like a defense against the scary unknowns, overabundance of opinions, and disturbing marketing schemes that come with entering parenthood. The medical community in America is poorly equipped to help women navigate the enormous emotional and societal pressures that come with birth and transitioning to motherhood. Too much of what pregnant women experience at the doctor has to do with dated ideas about our care, mandated by tradition or a fear of being sued rather than medical necessity. These practices, like weigh-ins at every appointment or medically unnecessary C-sections (which are estimated to account, horrifically, for almost 50 percent of all C-sections performed in the U.S.), only heighten anxiety.
Meanwhile, things that might alleviate stress – like having thorough discussions about the kinds of interventions we might be asked to accept at the hospital during labor and delivery – are left to outside educators and doulas that insurance plans typically don't cover. The net effect isn't better health outcomes for mom and baby, but rather a normalized sense of distrust many American women feel toward their OBGYNs, and the burden of going to every appointment and the delivery room on the defensive. Instead of being wed to dated medical practices and tangled in America's new motherhood industrial complex, shouldn't our doctors, of all people, be our biggest advocates?
As soon as I found out I was pregnant, I devoured Expecting Better, by Emily Oster, an economist who embarked on her own fact-finding mission during her first pregnancy, predicated on the belief that the advice OBGYNs have been giving pregnant women for decades is out of date and unnecessarily restrictive. The book includes controversial stances, like that having small amounts of alcohol while pregnant is OK. (More recent research has called this view into question.) Oster writes that for the vast majority of pregnant women, it's perfectly fine to lie on your back, do sit-ups, and eat Brie — all things I was relieved to learn I wouldn't have to give up for nine months, despite the traditional advice, which my doctor also gave to me.
Oster recommends hiring a doula, based both on research and personal experience. It's a worthwhile investment for those who can afford it: according to one study, 20.4 percent of laboring women with doulas had C-sections compared with 34.2 percent of women without them. A doula can do many things for a pregnant client, including helping her write a birth plan, massaging her back in labor, and cheering her on, which is especially useful for women who plan to labor without pain medication. Use of doulas is on the rise; according to DONA International, the world's largest and oldest doula association, the number of doulas who have been certified to date is over 12,000, up from 2,000 in 2002.
But the most significant role a doula plays is that of patient advocate in the hospital. This is a profound commentary on the way the medical establishment handles childbirth, a medical event that 86 percent of women aged 40 to 44 had gone through as of 2016. Recognizing the maternal mortality crisis in the U.S., where women are far more likely to die as a result of childbirth than anywhere else in the developed world and black women are three times more likely to die in childbirth than white women, a few states now allow Medicaid to cover doulas. Can you imagine feeling the need to hire an independent non-medical care provider to help you run interference with your doctors and nurses for something like an appendectomy?
I wouldn't have been aware of all the imminent interventions during my labor if my doula hadn't told me about them. Things happen fast in the hospital and doctors and nurses may rush patients to consent before proceeding with things like breaking their water or hooking them up to an IV of Pitocin. Only because my husband and I had spent six hours in birth class — a suggestion by my doula — did I realize that I was empowered to say "no" to such procedures.
Expecting more trustworthy advice to come from my doctor than books or Google or even a doula hardly seems unreasonable.
Of course, we all feel immense pressure to become good parents, and questioning conventional medical wisdom is a natural response to that pressure. "Looking around at the world and saying, who am I as a parent? What is important to me? Who are the wise people? What do I think wisdom is? What is a good decision? If you're a certain type of introspective person, if you're really asking those questions, that's going to include like taking a second look at things that doctors, for example, say," says Koyuki Smith, a doula and birth educator.
Expecting more trustworthy advice to come from my doctor than books or Google or even a doula hardly seems unreasonable. Yet my doctor's office seemed more concerned with checking off a list of boxes rather than providing me with personalized care that might have relieved my understandable anxiety about my first birth. When I still hadn't gone into labor around the time of my due date, my doctor encouraged me to be induced because my baby appeared to be large. I declined but scheduled an induction to "hold my spot" around the 42-week mark.
When I asked what medication would be used for an induction if I had one and she said Cytotec, I told her I had read that drug could cause serious complications, but she dismissed my concerns after I told her they stemmed from a book I read on natural childbirth. The FDA's page on Cytotec isn't exactly reassuring.
The nurse who took me in triage after I went into labor a week past my due date practically scolded me for waiting to go into labor naturally instead of opting for induction sooner. My doula told her while I was struggling to speak through labor pains to get off my case about it. I hadn't even become a mom and I was already doing so many things "wrong." Because I had done my own reading, I felt confident that my choices weren't harming my baby or me.
Becoming a mom would be less daunting if the medical community found a way to help women navigate the pressures of motherhood instead of adding to them. "Our culture at large doesn't support women enough in the complicated emotions that are a part of this process," said Alexandra Saks, a reproductive psychologist and author of What No One Tells You: A Guide to Your Emotions From Pregnancy to Motherhood. "I hope that every practitioner that works with women around reproductive health prioritizes her emotions around her experience."
For many of us, that will mean doctors who help us understand the pros and cons of conventional advice, don't use their offices as marketing channels, and don't pressure women into medically unnecessary inductions. Moms should also receive more attention after delivery both in the hospital and after they get home; a single, quick postpartum visit at six weeks is not an adequate way to care for women recovering from the trauma of childbirth, nor is it an adequate way to ensure women are emotionally supported during the transition. While several people interrogated me about my mental health at the hospital and my doctor's office just before and after birth, if I had been concerned about postpartum depression, I can't imagine feeling comfortable enough in those moments to tell strangers filling out obligatory worksheets.
It also means figuring out how to talk to patients who are prone to Googling their pregnancies with gusto every single day. It would be impossible for many women to shun independent research during pregnancy altogether. But it would also be nice if our doctors didn't add to our impulse to do it.