Apple Watch Identifies SARS-CoV2 Infection and Predicts Diagnosis

https://preprints.jmir.org/preprint/26107

193 102 5 years ago

preprints.jmir.org

sebmellen2• 5 years ago

This reminds me of a great interview with two ER doctors on Amanpour (PBS) two weeks ago. Pulse oximeters can be used to help detect which patients need hospitalization before they themselves notice, with astounding results.

I really recommend the episode: https://www.pbs.org/wnet/amanpour-and-company/video/how-earl...

Here's another article on a hospital implementing the early monitoring program https://www.nny360.com/news/publicservicenews/samaritan-util....

With the oximeter, Samaritan is asking patients to keep track of its measurements twice a day and to write the readings down. Then Home Health follows up with telehealth visits, either over the phone or via Zoom on days two and four, as well as days seven and 10.

danesparza• 5 years ago

This is happening now in hospitals with Covid-19. I know, because I'm married to a nurse. Nurses call them "happy hypoxics" because they have no idea their SPO2 levels are dangerously low -- but a pulse oximeter clearly indicates they need additional oxygen.

treeman793• 5 years ago

I had a pulmonary embolism‘s was white as a ghost struggling to breathe and that dang meter said everything was fine. Even the bloodwork at the hospital said everything was fine. Lost some lung over that and took a year to recover.

nradov5• 5 years ago

The current clinical recommendation for ambulatory COVID-19 patients at home is to go to the hospital if the pulse oximeter reading drops below 94%. Accurate pulse oximeters are cheap now so it's a good item to keep in your home first aid kit.

https://covid19criticalcare.com/i-mask-prophylaxis-treatment...

thebean11• 5 years ago

Mine frequently drops to the low 90s (or even 80s) based on the Apple watch, despite normally being 98-100. I'm certainly not in good shape, but still, should I be worried?

pkaye• 5 years ago

I would say thought that if your hands are cold, warm them up before you take a pulse oximeter reading.

linuxftw• 5 years ago

More than 2 doctors have reported positive effects with certain drugs to treat the infection, but those people are lambasted. What makes this anecdotal evidence any different? Shouldn't we report this as misinformation since it didn't come from an approved source such as the CDC or WHO?

sebmellen2• 5 years ago

I think it's definitely more than anecdotal! Take a look at the video — they're running large trials at a number of hospitals already.

And I think the two doctors share your same gripe, expressing frustration at the CDC not taking action to recommend these steps earlier.

vvram• 5 years ago

This has been standard practice in India for a while now https://mumbai.apollohospitals.com/covid-19-update/stay-i-at... Package includes oximeter, test sample collection, PPE supplies and optional food drop off. Includes a zoom cal with nurse/doctor at regular touchpoint intervals to facilitate hospitalisation

pintxo• 5 years ago

Now, will Apple add this as a feature?

joshdick• 5 years ago

It's crazy to think that a tech company like Apple might have the clearest picture of the pandemic

bilekas3• 5 years ago

I don't think it's specific for apple, they did mention that the participants just had the apple watch, but from the sounds of it, any GPS hear rate monitor would help..

I think Maybe a collective app simular to Strava might be a better place to get a collection of data maybe..

eli• 5 years ago

The Oura "smart ring" maker claims it can detect early Covid from variations in temperature https://www.fiercebiotech.com/medtech/oura-study-shows-its-s...

james_pm• 5 years ago

Amongst rich people with Apple Watches, maybe.

benbristow• 5 years ago

Hardly need to be rich to have an Apple Watch, they're not that expensive for a tech product really.

bilekas3• 5 years ago

This sounds great, I am going through the PDF, there's a LOT there..

But I'm not sure how reliable that it would be just to track the position (possible infection radius to known area) And the heart rate variability.. Its interesting though! Certainly every little helps..

blakesterz• 5 years ago

Ineresting. So... Prior to the diagnosis of COVID-19 by nasal PCR, significant changes in heart rate variability (HRV), were observed demonstrating its predictive ability to identify COVID-19 infection.

So in theory watching your heart rate closely you should be able to see it coming?

(I tried to figure out exactly what to watch for and how to measure it, but couldn't figure it out, hopefully someone else can explain if anyone with a watch could do this)

bilekas3• 5 years ago

That would make me nervous, which would mess up my heart rate.. :)

ryanmarsh• 5 years ago

Increased heart rate with decreased SpO2 commonly precedes diagnosis of respiratory infection. Increased heart rate alone is often seen as a warning to run pathology labs before beginning chemotherapy which can destroy neutrophils. Something you don't want to do if the patient is in the beginning stages of an infection.

I'm not a doctor I've just been around this stuff more than I wish to. Frankly I wish the Apple watch was more aggressive in reporting anomalies to the user. Something as simple as "we noticed your heart rate always increases at this place and time" can make the user aware that something is wrong in their life... assuming it's not a gym.

whoisburbansky3• 5 years ago

The measure they’re talking about, HRV, is measuring variance of the peak to peak and trough to trough between successive heartbeats. Individual heartbeats are on the order of one or two a second, but are remarkably consistent, so this measurement of variance is usually on the order of milliseconds.

Healthy ranges are, vaguely speaking, above 80ms, with unhealthy ranges being much lower, the idea being that when you’re sick or stressed, your heart rate control falls back to the nervous system since your brain has other things to deal with, making your heartbeat more consistent, which means lower variability. This is generally not great because you want to be able to switch up the spacing between beats on the fly for better efficiency, kind of like switching gears on a car.

All of this is to say that the measurement they’re talking about is pretty tiny and you’re unlikely to be able to measure it accurately manually.

t-writescode• 5 years ago

Healthy ranges are, vaguely speaking, above 80ms

I'm not sure what's being said here is safe or appropriate. If you're doing nothing, your heart rate variance won't likely change. There's also very little that matters about it, just normals, for you.

Every Google Search I've ever done on HRV has turned up that fact: HRV is incredibly personal and personal trends matter the most.

From my own experience, my HRV is low when I'm not doing anything - and why wouldn't it be? I'm not _doing_ anything. I have no need for sudden changes when I'm typing on a keyboard.

Further, you can be as healthy as a marathon runner and have very low HRVs.

_nickwhite• 5 years ago

"Longitudinally collected HRV metrics from a commonly worn commercial wearable device (Apple Watch) can identify the diagnosis of COVID-19 and COVID-19 related symptoms."

Having first-hand experience, I can confirm that my heart rate was WAY up, and my pulse-ox was WAY down when the virus was at its worst. I used the pulse ox value to make sure I was getting in good breaths (and yes, I know there is a hefty margin of error on these consumer devices.) I use a Garmin, but the sensors are pretty much the same on Apple Watch.

It would be pretty easy for the device to tell I was sick but probably impossible to tell I had COVID-19 instead of the Flu or a bad infection or maybe pneumonia.

miskin3• 5 years ago

In my case HRV went down almost 30% before I started to have symptoms with 50% of average on the worst day. Resting heart rate went up 35% on the worst day and respiratory rate went up 18%. But only HRV was obviously changed before I started to feel symptoms and became infectious.

mandis• 5 years ago

umm speaking from personal experience (comparing garmin reading with hospital oximeter), garmin is waaaay inaccurate sometimes! Maybe it is because I always shower with it, or maybe it just loses accuracy over time. Didnt give it a second thought and just disabled the sensor.

hobom• 5 years ago

I am kind of jaded, but despite the interesting approach, I predict that this research will not end up being deployed in time to make any difference. The real world pipeline just takes too long.

secretsatan• 5 years ago

Surely more than 1 condition can cause heart rate changes? Is there a pattern they can match, or is it the most likely cause?

pwinnski• 5 years ago

From my reading, many respiratory illnesses can cause these symptoms, but right now if you have a respiratory illness at all, odd are it's COVID-19, so it's worth at least getting a PCR test. And if it's not that, you have a very serious flu or something which probably requires treatment as well.

miskin3• 5 years ago

You are right, I had similar data and same warning as I got for COVID-19 from Oura cca year ago with regular flu. It is now more important because of COVID-19, but it is also very helpful for any similar illness that one may spread.

l33tman• 5 years ago

There are lots, as what you really are measuring are subtle variations in the sympathetic and parasympathetic drives of the heart by the autonomous nerve system. This can get affected by lots of things, a quick googling provided dozens of completely different papers looking it stuff like heart disease itself, but also clinical depression etc.

sschueller• 5 years ago

https://news.ycombinator.com/item?id=26079918

victor1062• 5 years ago

Slightly OT:-

I really hope Apple Watch SPO2 is more accurate.

The current version is not accurate enough to use as a replacement for a pulse oximeter

https://www.medpagetoday.com/blogs/skeptical-cardiologist/88...

whoisburbansky3• 5 years ago

Agreed, but the article is about using HRV, not spO2

victor1062• 5 years ago

Agreed, This is tangential to that article.

screamingninja4• 5 years ago

Title is misleading IMO. The study has nothing specific to do with Apple Watch. They mentioned that they used "a commonly worn commercial wearable device (Apple Watch)" for testing. Any device with continuous heart rate monitoring will do.

zepto4• 5 years ago

They know the Apple Watch works.

They haven’t tested any other devices.

This is about the Apple Watch.

Your comment is supposition. Likely correct, but not guaranteed.

screamingninja4• 5 years ago

Your comment is supposition. Likely correct, but not guaranteed.

No, the paper was very clear that Apple Watch was used to measure Heart Rate Variability (HRV). There is absolutely no mention of any unique advantages that Apple Watch provided in the given scenario. The study is about using the HRV data from a wearable device to identify indicators of COVID-19; it is not an endorsement or an advertisement for Apple.

Abishek_Muthian• 5 years ago

Considering the proliferation of fake pulse-oximeters due the pandemic, it might be easy to go for Apple Watch if one can afford it and have access to it.

I got a FDI approved pulse-oximeter accidentally from Amazon(US)[1] after realizing almost every pulse-oximeters sold online where I live were making false claims[1].

[1] https://abishekmuthian.com/testing-fda-approved-pulse-oximet...

yoz-y• 5 years ago

Note though that the study does not use (or even mention) the oximeter. They use heart rate variability.

Edit: They probably also used the older model as the study was submitted in November and the Apple Watch with oximeter came out in September, and was seriously supply constrained.

IgorPartola• 5 years ago

Whatever happened with the MIT cough analyzer? That seemed like really promising tech that just kind of fell off the news feeds and was never mentioned again. I thought they were trying to apply for an FDA approval. Latest info is 47 days old: https://www.bbc.com/news/technology-54780460?fbclid=IwAR1bGR...

2wrist2• 5 years ago

There have been a few cyclists who use whoop and it picked up on HRV and they could see that something was not right.

Hopefully HRV gets added to the AWatch soon, if it isn't already. (C'mon Apple, deliver my device!)

It is pretty cool that we can take these measurements and hopfully make data driven decisions. Hopefully in time we can use these measures to be prescritive and be guided to make better decisions.

jjevanoorschot• 5 years ago

Heart Rate Variability is already measured throughout the day if you wear an Apple Watch. You can find the data in the Health app.

2wrist2• 5 years ago

thanks for that! I wasn't sure.

ben1040• 5 years ago

Yep. It takes a sample every few hours, but you can also get a HRV measurement on demand by running a session in the Breathe app on the watch.

It doesn't tell you anything about HRV in the Breathe app or that it took a new sample for you, but you'll find a new entry in the Health app if you go look right afterward.

vrc2• 5 years ago

This is basically how the WHOOP band works. Anyone with an Apple Watch curious to see can find your tracked HRV in the Health App on your iPhone.

However, looking at heart-rate (HR) itself will be misleading. Big swings in HR or high HR in general usually misinterpreted as having high HRV, when it's often the exact opposite. HRV is a measure of the variability of 1/(inter-beat time). So it's measuring the time-average of really small variations from a set point.

And counterintuitively, HRV is usually highest when the sympathetic (flight or fight) nervous tone and HR is lower. In those situations, the parasympathetic control dominates, and small wiggles caused by "noise on the wire" conducted directly to the heart's pacemaker via the vagus nerve increases HRV. Often times this is when HR is lower, and because higher HR or spikes in HR are often caused by increased sympathetic tone, this leads to a blunting of this "parasympathetic noise".

Source: https://journals.physiology.org/doi/full/10.1152/physiol.000...

grok22• 5 years ago

Is there something else like the WHOOP band, but sold as a standalone device (the WHOOP band is given free with a fitness subscription service!)?

vrc2• 5 years ago

I track mine on my Apple Watch which records it in the Health App. It's basic graph and I can download it if I want, but I've found tracking day-over-day/week-over-week is a good enough signal. For example, I did dry January this year and practiced meditation every day since and I've seen a step-jump up corresponding to that.

Still have to keep another record of external factors to correlate with it, though. I've heard people finding success with a 3p monitor and the Elite HRV app as well [0].

[0] https://elitehrv.com/

pmw• 5 years ago

I've never had the WHOOP, but I use Apple Watch combined with iPhone apps to track heart metrics. I recently discovered AutoSleep and HeartWatch, which both track HRV along with other metrics.

aorth• 5 years ago

Offtopic: what is up with this website? I just clicked the link and noticed that Firefox downloaded the paper's PDF 55 times automatically before I closed the window!

kristjansson• 5 years ago

It gets points for being a novel form of broken!

auslegung• 5 years ago

Is there anything actionable for us, today, in the study? I’m not skilled in reading these, I read the first few paragraphs and knew I was over my head.

freitasm• 5 years ago

Apple Watch and any other HR monitoring watch...

stuartbman4• 5 years ago

So some big limitations, speaking as a doctor. Firstly, I'm surprised that they allowed watches on the ward. They're a huge infection risk and most places are bare below the elbows (NHS), moreso for covid. Secondly, they only looked at symptomatic covid cases (1 day before symptoms started was their prediction as far as i can tell. This is completely useless as the 24hrs before symptoms start the patient is likely to already be highly infectious, and misses the asymptomatic carriers which have an indeterminate effect on spread as well. Far better to use the semi-proven (but equally controversial) lateral flow tests and avoid these risks. In the UK, hundreds of healthcare staff have been identified as covid+ >48hrs before symptoms in this way.

rgbrenner• 5 years ago

Speaking as a non-doctor, I don't have any lateral flow test supplies or equipment. Do they sell that on Amazon?

But seriously, a test I don't have easy access to is not an alternative. A lateral flow test has no predictive value to me because I'm never going to get one before I'm actually sick.

sveme• 5 years ago

Lateral flow tests are rapid test kits to my understanding, so they should be available on Amazon if accepted by your local medical devices authority.

zamfi3• 5 years ago

But seriously, a test I don't have easy access to is not an alternative.

Do you have access to the custom Apple Watch app they used here? I don't either.

Health authorities could make either of these available to the general public -- the parent poster is making a comment about which is more valuable under the assumption of access.

You're not wrong, a test you don't have access to obviously has no predictive value for you, but right now we (the public) have access to neither, so this isn't a distinguishing factor.

Now, if you're making the argument that the Apple Watch app would be easier to distribute, then you can read the parent's criticism as "sure, but only knowing after you've potentially spread it is not very useful."

yread• 5 years ago

On the other hand Apple Watch costs like 400$ and UK just bought 400M lateral flow tests for 1.3Bn pounds

https://www.bmj.com/content/372/bmj.n287

Or you can buy it online for 250$/10 tests (if you can swallow that you're being fleeced this much)

diebeforei485• 5 years ago

Why are watches an infection risk?

BitwiseFool• 5 years ago

I assume it's because they accumulate crud and bacteria. You can wash your hands but you never really wash your watch. I also assume that because it's on your wrist every time you scratch your body or touch your face the bacteria covered watch deposits something icky on contact.

tinus_hn2• 5 years ago

You state:

they only looked at symptomatic covid cases

Which means the study cannot be used to prove or disprove this claim:

and misses the asymptomatic carriers

Why is there such a need to hastily dismiss any potential improvement?

stuartbman4• 5 years ago

Did they perform regular PCR testing on staff? No, and so they didn't detect any asymptomatic carriers. By comparison, all NHS staff are doing biweekly lateral flow tests, and hundreds of staff are detected prior to symptoms this way. This means that fewer staff are off sick/isolating, and more staff are available to care for patients.

ggm• 5 years ago

it is not unheard of for something at level x to be developed to level 2x so if it can do 24h now, with higher sample rate and better maths, what if it got to 48h in tractable time?

to the watch-in-a-ward point: valid. But, if this technique did get to 48h+ predictive quality, and was available to wearers of smart watches outside of wards would you still have hesitancy to consider it useful?

stuartbman4• 5 years ago

The utility of the test decreases with reduced risk. A 99% specific test is good when there are high levels of disease going around (e.g. covid in a hospital). In the community, rates are much lower, so the positive predictive value of the test is much lower, even with 99% specificity. My conclusion is that if you tried this in a community setting, the number of false positives would far outweigh the true positives, and lead to dismissal of alerts.

nradov5• 5 years ago

For reducing infection risk one option is to keep the watch in a pocket while working on the ward and wear a separate wireless heart rate monitor on the chest or upper arm. I don't think they did that in this study, just pointing it out as an option for healthcare workers who want to track their HRV on the job.

kelnos2• 5 years ago

Getting a warning 24 hours "early" that you might be infected is still useful. Perhaps in that 24 hours you were going to make a grocery trip and potentially infect a bunch of people, but now you won't because you got that early warning.

Claiming that something is useless because it doesn't cover all cases seems a little weird to me. It's a tool in the toolbox that can reduce the possibility of spread in a limited set of cases.

Using lateral flow tests requires everyone to purchase a big supply of them and use one every day. This watch-based warning just requires you to have an Apple watch and run a new app on it (which I hope they'll make publicly available), and it'll just let you know without any extra action taken. Your average Apple watch user is probably pretty likely to take the simple step of installing a new app; they're not going to buy a supply of lateral flow tests (which they probably don't even know much about or haven't even heard of) and test themselves every day.

rimliu• 5 years ago

Yup. I was lucky the person whom I contracted COVID from informed me the moment they got the test result. I was on my way to work, just about to leave the car. Turned around and went back home. Developed symptoms the same evening. It was a lucky coincidence that was Monday so I've stayed home the whole weekend and had no contacts for a couple of days I was likely already infectious. (The person I got it from only developed symptoms two days after our contact). People who do contact tracking only on Wednesday. So my contact informing me saved three days worth of my potential contacts from getting COVID from me.

stuartbman4• 5 years ago

I can only comment on the study in front of me, and not the use cases that 'might have been'. In this case, they tested in a healthcare setting as there is a presumed higher risk of catching covid amongst participants. Would the same false positive rate be true in the community, where transmission is much lower? We don't know because that wasn't the experiment. The study authors claim that this is useful in the healthcare setting- I'm saying that it's useless because there are better tools in the arsenal (lateral flow tests), and watches are an infection risk.

Closi• 5 years ago

This is completely useless as the 24hrs before symptoms start the patient is likely to already be highly infectious, and misses the asymptomatic carriers which have an indeterminate effect on spread as well.

Nothing is a one-shot-solve-all solution to Covid. If Apple watches can detect it and prompt people to go get a full test, that’s great. I’ve got an ongoing theory that a lot of the spread is by people who ignore their symptoms because ‘they have a cough but it’s not a covid cough’ or ‘they haven’t lost their smell so it can’t be covid’ so the more things that can prompt you to get a test and isolate the better.

BjoernKW• 5 years ago

A "bare below the elbows" policy makes sense and there indeed are studies corroborating that pathogens can accumulate on wristwatches.

However, having worked as a paramedic I'm wondering how you would actually measure a patient's heart rate without a watch and with no additional equipment around.

Not every patient will be on cardiac monitoring, after all.

Yes, there are those nurse watches you can attach to your shirt or white coat but in order to take a proper look at those they have to be touched as well, which kind of defeats the purpose.

germinalphrase2• 5 years ago

I wish I could buy a watch that continuously monitored my hydration levels. So many health concerns are directly impacted by hydration.

Edit: My comment meant to recognize that while this tech doesn’t yet exist, it would be helpful as people end up in the hospital all the time for medical problems that are exacerbated by dehydration. Simply saying “drink water when you’re thirsty” is beside the point.

uncledave2• 5 years ago

Use the Apple Watch. It reminds you to stand up every hour. Go pee then. If it’s not clear then drink a glass of water. Works for me.

germinalphrase2• 5 years ago

I don’t really have a desk job, so a timed reminder wouldn’t be as useful to me as actual data.

nradov5• 5 years ago

If you're thirsty then drink some water. We have no reliable clinical evidence that drinking extra water when you're not thirsty causes improved health.

So far no one has succeeded in building a reliable, wearable, non-invasive hydration sensor.

https://www.dcrainmaker.com/2019/11/lvls-hydration-sensor-ri...

eightysixfour• 5 years ago

Oura Ring also ran a study on this (which I was a part of). It is interesting because in 2019 I had a severe cold and the Oura Ring gave me a very low "Readingess" score in the 2 days leading up to it, despite me feeling fine and getting good sleep. I had never had readiness scores so low prior to that or since, so I don't believe it was any sort of confirmation bias.

Quantified health is going to bring about some amazing QOL improvements that we're still only beginning to understand and it is one of the areas I am most bullish about for sure.

14• 5 years ago

This does not surprise me one bit. I have a child and every time he gets sick his heart rate rises. The last time I noticed the heart rate first and called his mom telling her I think he is getting sick. The next day he had a fever.

floatingatoll• 5 years ago

I’ve been donating my heart data to the Scripps study in this space, too. Glad to see someone nailed down the link in at least one instance.

Apple Watch Identifies SARS-CoV2 Infection and Predicts Diagnosis

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