Apple Watch Can Detect Covid-19 a Week Early, Study Finds

In the early days of the pandemic, dozens of researchers launched studies trying to see whether wearables of all sorts could potentially identify covid-19 before symptoms began. In one such study, researchers from Mount Sinai discovered that the Apple Watch was capable of detecting the onset of covid-19 up to seven days before current testing methods.

The study, which was published in the Journal of Medical Internet Research, studied the impact of covid-19 on several hundred healthcare workers at Mount Sinai Health System between April and September of last year. All participants wore an Apple Watch and answered daily surveys about symptoms via an app. The researchers then observed changes in the participants’ heart rate variability (HRV), which measures the changes in heartbeat and is an indicator of your autonomic nervous system.

The interesting takeaway from this particular study is that firstly, subtle changes in a person’s HRV helped researchers identify and predict whether that person might be infected with or have symptoms of covid-19 a week before they were ever tested via a nasal swab. That’s big, as covid-19 can be contagious before any symptoms manifest. A week’s heads up is so far among the longest lead times we’ve seen reported. Another tidbit was that HRV patterns returned to normal 7-14 days after diagnosis, to the point where they weren’t statistically different from uninfected participants.

“This technology allows us not only to track and predict health outcomes, but also to intervene in a timely and remote manner, which is essential during a pandemic that requires people to stay apart,” said study co-author Zahi Fayad, PhD, said in a press release.

This is in line with the idea that wearables might be a useful tool in triaging testing, as well as potentially identifying illnesses in pre-symptomatic stages. Several other researchers have also identified HRV as a potential metric for detecting infections, while others have also pointed to respiratory rate and body temperature as potential signifiers as well. And while studies are currently being conducted with the Apple Watch, Fitbits, and Garmin devices, among others, the wearable that’s gotten the most press with regard to covid-19 remains the Oura Ring. The Oura Ring was the wearable of choice for the NBA in its reopening efforts, and some promising preliminary research found it could detect covid-19 up to three days before symptoms appeared with 90% accuracy. That said, it bears reminding that whatever headlines you read, none of the aforementioned wearables are capable of officially diagnosing covid-19. Also, just because this study focused on the Apple Watch, it doesn’t necessarily mean other wearables wouldn’t be capable of the same thing.

It’s also been about a year since many of these studies launched, and we’ll likely see some more findings released in the coming weeks and months. However, whatever findings do come to light, it’s possible that consumers won’t see “early illness detection” features on their personal wearables during this pandemic. That would require some degree of FDA clearance, which is typically a slow process. Even so, it’s also possible that these findings will help doctors better manage future flu outbreaks or even remotely monitor patients.