sTeamTraen wrote: ↑Thu Dec 10, 2020 5:54 pm
monkey wrote: ↑Thu Dec 10, 2020 4:26 pm
I don't think you're wrong, but could it be useful in that you could use it to get people tested before they develop symptoms or get spready? It doesn't have to be good at finding The Covids or discriminating between illnesses, just find candidates for testing earlier than they would normally. That seems useful to me. Kind of like how it works already, having two symptoms means you should get a test, but does not mean you have The Covids. The two symptom method would have a high false negative rate if you were using that for diagnosis, but it's useful for determining who needs a test.
But the number of tests available is also a finite resource (and reaching saturation in some places right now), so if every FitBit owner got a signal saying "get a test" and turned up to demand one, you would have a new problem.
If r is greater than 1, for every person that is positve, you have to do more than one test, because you have to test the people they passed it on to too. If you can get them tested before they do the spreading, you can get them to isolate before they do the spreading, lowering r, so fewer tests needed. If r is less than one, testing capacity shouldn't be a problem, because it should be improving relative to the disease prevalence. If the false positive rate is high, that may mean there are more tests needed, so there'll be a threshold for that, but the specificity may not need to be that good for this to be useful. That'll depend on how much earlier you can detect the disease.
Also, I didn't mean to suggest that it could be done based on this data, they'd have to do an actual test on how good it is at predicting and work out what the false positive rate would be. Just thought that this might have potential, and shouldn't just be dismissed before more work is done.
But yeah, it might be pointless too, especially as I don't think too many people wear these things, and they might not be a useful subset of the population to target with your resources.