How the WHOOP fitness wearable uses Data Science to help you detect a pre-symptomatic COVID-19 infection
The case of professional golfer Nick Watney and how WHOOP saved the PGA Tour
When Nick Watney woke up on the morning of June 19, 2020, the RBC Heritage Golf Championship’s second tournament day, he went through his typical morning routine. As he checked his phone, he recognized that something was off. For about 1 year he had been using the WHOOP fitness strap to track his strain, recovery and sleep based on the wearable’s advanced technology that includes sensors measuring heart rate and motion. It has become a tool of his performance management system, including the analysis of sleep quality every morning through the metrics shown by the WHOOP app.
Specifically, one metric he inspected that Friday morning, the respiratory rate, made him wondering. The respiratory rate is the amount of breaths taken per minute during sleep and is calculated by the WHOOP sleep coach function besides several other metrics like the hours spent in the different sleep phases.
Although Watney felt a bit tired the afternoon before due to an early wake-up call for his first tournament round, his general physical condition seemed to be fine. But now the respiratory rate was off — by a lot. Whereas Watney’s values typically were in a tight range around 14 breaths per minute (bpm) for the whole time since he had started using WHOOP, the value detected by Watney on that morning was 18bpm. As WHOOP analysis shows that individual respiratory rate has a standard deviation of around 0.5bpm, a pretty tight corridor around the average, there was definitely something going on.
“In studying 25,000 WHOOP members, we learned that respiratory rate changes very little on a night-to-night basis. We found that the average WHOOP member’s standard deviation was about half of a breath per minute. This is something that had never been documented before, what normal, night-to-night variation in healthy people is in their respiratory rates.” (Emily Capodilupo, VP of Data Science, WHOOP)
Although such a dramatic increase could have had other reasons (like e.g. air quality, altitude, smoking or drinking), nothing of this really applied to Watney, so the result was definitely worrying. Especially, since he heard about detected COVID-19 infections by the help of the wearable’s data and the company’s intensified research activities around respiratory rate.
Watney took a mandatory COVID-19 test earlier in the week as part of the PGA Tour’s newly introduced protocol that allowed for continuance of professional tournaments under increase hygiene and security measures.
Although tested and non-symptomatic, he now took the initiative to contact the tour’s medical staff again to discuss his concerns of potentially having contracted COVID-19. The tour officials went through the checklists with Watney, but declared him ready for competitive play and send him to warm-up. However, he was tested again as a safety measure. During his warm-up session on the practice range, where he had been social distancing, Watney received the test result to learn that the test came back positive. He was instructed to immediately leave property and quarantine, which he did.
Nick Watney’s case was among the first COVID-19 cases on the PGA Tour since the resume of competitive play after the first lockdown in spring 2020. By his responsible behavior Nick Watney bewared lots of fellow players and staff around him from the danger of getting infected as well. Clearly blown away by this experience and the capabilities of WHOOP the PGA Tour organization procured more than 1,000 WHOOP straps for players, staff and media representatives to support the security measures the Tour brought in place to continue with professional golf tournaments under a contact-reduction and regular testing protocol.
Effectiveness of WHOOP respiratory rate tracking validated by peer-reviewed research
Since outbreak of the Corona virus, WHOOP has received lots of user input around the linkage of COVID-19 infections to increased respiratory rate.
“Just over three months ago, I woke up to a message from a colleague showing me that one of our members had posted on social media about contracting COVID-19, and how his vital signs, as measured by WHOOP, had changed. One of the most dramatic differences we saw was in his respiratory rate. Not only did it jump an extraordinary amount, but his respiratory rate started rising during incubation before he realized he was sick.” (E. Capodilupo, WHOOP)
Originally, the respiratory rate had not even been part of the metrics shown to the customer through the app. As this metric should normally be fairly constant, it does not provide much interaction value for users on a daily basis. But with the pattern of elevated rates arising in connection to COVID-19 infections, the metric has clearly proven it’s value for health tracking and COVID-19 prevention, so WHOOP included it in the app’s sleep tracker category.
To intensify the research efforts behind the pattern, WHOOP partnered up with Australia’s Central Queensland University to eventually understand if this was just coincidence or if respiratory rate could be a valid indicator of COVID-19. On June 22nd, WHOOP shared their research insights and submitted a research paper for peer review and publication on “the utility of wearable technology in providing early warning signs of potential COVID-19 infections” — truly a remarkable achievement and first-of-its kind submission for a commercial provider of wearable technology. In early December, the peer reviewed research piece has been published in the journal Plos One under the title Analyzing Changes in Respiratory Rate to Predict the Risk of COVID-19 Infection.
“Over the past few months, WHOOP members have shared via our Journal feature their diagnoses of COVID-19, as well as many instances where suspected cases of COVID-19 resulted in negative tests. Using that data, we were able to derive an algorithm capable of identifying 80% of symptomatic COVID-19 cases simply from examining changes in respiratory rate from each member’s personal baseline. That’s pretty amazing.” (Will Ahmed, CEO, WHOOP)
During their research efforts the team was able to specify the pattern, which seems so indicative for a COVID-19 infection and can indeed be picked up by the wearable’s sensors. It is when the respiratory abruptly increases from the baseline, breaks out of the typical range and, specifically, if this continues over a couple of nights, it can be a sign for a COVID-19 infection. The 2-day increase of respiratory rate seems like the distinguishing factor compared to sighs of other illnesses (i.e. the flu).
“What is particularly unique about COVID-19 is its long incubation period. So we believe that the reason why we’re seeing this pattern of the gradually increasing respiratory rate over the course of a couple nights is because what we’re actually seeing is the incubation. The infection is setting up shop, for lack of a better term, in your lungs prior to when you would actually consciously feel symptomatic, but that efficiency loss is there so the respiratory rate starts to rise to compensate.” (E. Capodilupo, WHOOP)
How to include WHOOP data into your personal safety measures
It is pretty clear that the tracking of respiratory rate with WHOOP cannot fully replace testing and vaccination. However, it can be a useful early warning system that something might be up and a trigger for getting tested, as an elevation in respiratory rate can be an acute sign of an infection. Especially, since continuous testing for the public is a complicated and cost intensive effort, the WHOOP wearable provides a practical solution for increased safety.
“The best way to think about how to use something like this is to know that this elevated respiratory rate can be an acute sign that you do have COVID and you should use that as an invitation to get tested and be that much more conscientious about your social distancing and not having any unnecessary contact with anybody. But we’re actually not at a point right now that if your respiratory rate is constant that I would say carte blanche to go do whatever you want, you don’t have COVID. We just haven’t seen enough, and certainly not with this paper, of what happens with people who are totally asymptomatic. It’s possible they would have a similar pattern, but we don’t know that yet.” (E. Capodilupo, WHOOP)
Wrap-up: WHOOP respiratory rate tracking
Using respiratory rate tracking provided by WHOOP provides various benefits and by all means a very practical approach to increased medical safety during COVID-19 times.
By adding the WHOOP wearable as an additional tool to individual security measures against COVID-19 you get access to non-invasive and early detection of a potential infection, potentially ahead of the curve while symptoms are not yet an indicator.
With recent admission of vaccines the current transition phase WHOOP can be a valuable addition to bridge the gap until herd immunity and for a safer return to office and accelerated “back-to-normal”.
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Disclaimer Whoop.com: The products and services of WHOOP are not medical devices, are not intended to diagnose COVID-19, the flu or any other disease, and should not be used as a substitute for professional medical advice, diagnosis or treatment. All content available through the products and services of WHOOP is for general informational purposes only.