> 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."
> Do you have access to the custom Apple Watch app they used here? I don't either.
That's pretty immaterial when discussing theoretical effectiveness. Obviously, getting wide use depends upon it getting packaged up into an app listed on the app store, and some sort of awareness push.
That needs to be done once, by the app's authors. For lateral flow tests, to have similar effectiveness, that means that literally every Apple watch wearer (just to assume a similar population size) needs to get themselves a supply of tests (and keep getting new tests when they run out), and remember to perform the test every day. That is a much higher hurdle to jump than getting this app onto people's watches (assuming their study is correct and can be independently verified!). I also expect the supply of test kits is not robust enough to handle that kind of demand.
> 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."
Reducing spread potential by 24 hours when you've perhaps been spreading it for a week already isn't exactly a game changer, but it's still useful, especially if the only thing people have to do is install an app on their watch. Expecting everyone to obtain rapid test kits and test themselves daily is in general a non-starter.
> That needs to be done once, by the app's authors.
Except...it also needs FDA approval as a diagnostic, etc., which is probably easier said than done.
Obviously it's easier to distribute an app than lateral flow tests -- but the latter are much more effective too.
Clearly, we should do both, and...
> Reducing spread potential by 24 hours when you've perhaps been spreading it for a week already isn't exactly a game changer, but it's still useful, especially if the only thing people have to do is install an app on their watch. Expecting everyone to obtain rapid test kits and test themselves daily is in general a non-starter.
This totally depends on your goals. For the individual with limited outside exposure, is knowing 24h before you feel symptoms useful? Absolutely.
For a hospital or other institution (school?), who can order in bulk, and then mandate, lateral flow tests every day before work starts and observe their correct use (without having to rely on self-reported app results), the tests seem much more useful.
The data is all readily available in the default Apple health app.
Yes, to make these same predictions you'd have to do some statistics as described in the paper, but no special app is required.
(And that's why this finding is interesting: they have the data available from patients before they were sick, because every new Apple Watch records this data out of the box.)
Yes, the finding is definitely interesting because it suggests that we could make this available very broadly (i.e., anyone with an appropriate Apple Watch) without needing to ship a bunch of hardware.
But the limitations are worth noting: you may already have infected people by the time this detects your illness. That isn't true for lateral flow tests, making the latter more useful as a preventative testing tool (again, in the absence of access differences).
However, I don't understand what you're trying to say with this claim:
> Yes, to make these same predictions you'd have to do some statistics as described in the paper, but no special app is required.
"Do some statistics" is approximately as impossible as "order lateral flow test reagents" to the general public -- a consumable version of either the process described in this paper, or the lateral flow kits mentioned earlier, needs to be produced by someone skilled here, in order for this to be useful to the general public.
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."