Am writing to get inputs on an important statistical issue relating to understanding the pandemic. Would like inputs from anyone in the world who has worked on it. It relates to the error rates of various tests being used to detect #Covid19 #CoronaVirus 1/n

There is now a wide variety of tests being used worldwide. Is there an authentic study of their error rates (i.e. false positives & negatives)? When applied over large numbers, even small error rates can balloon out. How good are the confirmation tests? 2/n

This is not a trivial technical issue. Let me illustrate the point with a simplified example. Let us say there is a test that is 99% accurate (incidentally this is far more accurate than most Covid19 tests) and it gives a false positive 1% of the time. 3/n

When used in a population with 1/1000 infection rate, it will likely find the infected person. But it will also show 10 false positives. In short, only 1/11 is actually infected after testing positive. Here the confirmatory test is critical to weed out the false positives 4/n

This is why we need to know the error rates (both +ve & -ve).Also, need to know how many are being subjected to an independent confirmatory test, and the accuracy of that test. Have been scanning the net & asking experts for credible data but cannot find it,so asking for help 5/n

Of course, am trying to pull this information from official channels - but sometimes social media may just get me there faster by connecting me to the right researcher 6/n