Re:FDA just cleared a $20 Covid-19 antibody test
by kragen on Saturday March 21, 2020 @03:44PM
(#22649333)
0.01% of 1000 is 0.1 people, not 1 people, and 82รท1 is 82 and not 8, but you're right that my calculations weren't correct either. You'd get 82 false positives and 0.1 (or 0.0979) true positives, so for every true positive result, you have 820 false positives, not 82300 as I said.
With a population size of 1000 and with 0.01% of the population infected (i.e. 1 individual) with this test we'd get 82 false positives and 0.979 true positives.
For every true positive result in your population, you'll have 8 false positive results and 0,021 false negatives.