Got a Cold? Your Smartwatch Can Detect It Before You Do

Wearable devices have increasingly been used over the last few years to signal to people when they might have a health issue. Some smartwatches, for example, can detect when the wearer has a heart rate that’s too high or too low, or when their sleep patterns are off.

Now, new research has found that wearable devices may be able to detect when someone is sick, even before they develop symptoms.

That’s the major takeaway from a new September study published in JAMA Network Open. For the study, researchers had 31 people wear Empatica’s E4 wristband.

That smart device recorded information on the participants’ heart rate, skin temperature, movement, and how much electrical activity was on their skin. They were then infected with either the H1N1 influenza virus or rhinovirus. 

Once the study participants were exposed to their respective viruses, they were asked to report their daily symptoms. Researchers also measured how much of the virus they shed on a daily basis.

The data collected by the wearables was used in an algorithm that predicted how likely someone would be infected and how severe their illness may be.

The researchers compared the participants’ data after they were infected with their pre-infection measurements and found that the wearables were able to detect those who developed an infection and didn’t develop an infection with 92% accuracy for those who were exposed to H1N1.

Those who were exposed to rhinovirus had an 88% detection rate with the wearables. The devices could even tell the difference between mild and moderate infections 24 hours before participants developed symptoms, with 90% accuracy for H1N1 and 89% accuracy for rhinovirus.

“This study suggests that the use of wearable devices to identify individuals with presymptomatic acute viral respiratory infection is feasible,” the researchers wrote. “Because wearable devices are common in the general population, using them for infection screening may help limit the spread of contagion.”

The researchers also made comparisons to detecting SARS-CoV-2, the virus that causes COVID-19.

“In the midst of the global SARS-CoV-2 pandemic, the need for novel approaches like this has never been more apparent, and future work to validate these findings in individuals with other respiratory infections, such as COVID-19, may be critical given the highly variable and potentially severe or even fatal presentation of SARS-CoV-2 infection,” they wrote.

Other Research Links Wearables to Early Detection

This isn’t the first study to analyze how smart devices could help detect an early illness in patients.

“There’s been a strong interest in harnessing all the data that’s available to wearables in order to help detect subtle differences in physiology that could be used to diagnose illnesses at a very early stage,” Amesh A. Adalja, MD, infectious disease expert and a senior scholar at the Johns Hopkins Center for Health Security, tells Verywell. “I do think that this type of work is very exciting and likely will come to fruition eventually.”

One study, published in the journal Nature Medicine, in October of last year, developed an app that collected smartwatch and activity tracker data from over 30,000 people to see whether it could detect early symptoms of COVID-19. 

Of those study participants, 3,811 reported having symptoms, and 54 tested positive for COVID-19. The researchers found that the smartwatch was able to pick up a change in symptoms like sleep habits and activity levels with an 80% accuracy.

Another study, published in the journal Scientific Reports, in December 2020 had participants wear smartwatches that continuously monitored their temperature, along with their reported symptoms.

Researchers found that the devices were able to detect increases in bodily temperature in those participants that lined up with what they reported. It’s worth noting, though, that these studies didn’t detect that people were sick before they developed symptoms—they simply confirmed those symptoms were happening.

What Happens Next

Research is continuing to see how much smart technology and wearables can help detect illnesses.

Duke University, for example, has an ongoing study called Covidentify that is actively recruiting people to see if the data from your smartphone and smartwatch can help determine whether or not you have a COVID-19 infection.

Adalja says it’s plausible that wearables could one day be used for the early detection of infections. “When someone has an infection, there are changes in heart rate characteristics and other physiological measures that can be a clue that an infection is present,” he says. “Some of these changes are hard to detect because they may be minute.”

"[The challenge with wearables] will be in distinguishing between different viruses that have similar clinical presentations," Adaja adds. “Technically speaking, there’s no reason why this couldn’t be done for a whole host range of infections.”