Current Affairs

COVID-19: Testing Accuracy Information

Every week or so there is new bad information about COVID-19.

Quite frankly it is annoying.

For the past few weeks there has been a lot of people shouting about testing accuracy. People seem to think that all the tests only have a 75% or less accuracy.

The reality is that there are two kinds of tests that give you two different pieces of information and each test has significantly different accuracy.

One test is an antibody test which tells you if you’ve _had_ the disease. This test has ~<75% accuracy.

The other test is a diagnostic test which says if you currently have the disease. All the diagnostic tests used in the US have over a 90% accuracy, with the exception of one which has a specialized use case which I don’t understand.

It’s also important to note that the majority of testing in the US is diagnostic tests. So if you here that 3 million people have been diagnosed with COVID-19 then the worst case is that there were really only 2.7 million people.