Re:Stanford Student Claims to Run Bootleg Covid-19 Testing Lab
by astrophysician on Friday March 20, 2020 @09:27AM
(#22637329)
Really? That test is meaningless. It screws up the numbers, and you might as well do a complete quarantine anyway, since you need to not just quarantine but isolate anyone who’s positive.
Let’s say there’s 100,000 people in the US with covid right now (like 10x the measured number)
FPR =0.5
TPR = 1
Disease rate = 1e5/3.3e8 = 3e-4
P(you have covid| test is positive) = 3e-4/(0.5(1-3e-4) + 3e-4) = 0.06%!!
This is less than useless. Now instead of tracking the disease you are completely overwhelmed with false positives and the result is exactly the same — everyone stay home.
Let’s say there’s 100,000 people in the US with covid right now (like 10x the measured number)
FPR =0.5 TPR = 1
Disease rate = 1e5/3.3e8 = 3e-4
P(you have covid| test is positive) = 3e-4/(0.5(1-3e-4) + 3e-4) = 0.06%!!
This is less than useless. Now instead of tracking the disease you are completely overwhelmed with false positives and the result is exactly the same — everyone stay home.