US numbers could be skewed by testing. I live in Illinois; quite a few of employers require weekly testing for unvaccinated only. Same with high schools, a large percentage of students over 12 yrs old are vaccinated in Chicago and northern suburbs, and only unvaccinated kids are subject to weekly testing. These tests have a low PPV (p…
US numbers could be skewed by testing. I live in Illinois; quite a few of employers require weekly testing for unvaccinated only. Same with high schools, a large percentage of students over 12 yrs old are vaccinated in Chicago and northern suburbs, and only unvaccinated kids are subject to weekly testing. These tests have a low PPV (positive predictive value, P(sick | positive test) ), the one in schools around me is about 50%.
So to give a bit more color... one of the school tests has a false positive rate of 1% and false negative of 3%. Assume 1% of population is sick at any given time. That number is a bit larger than the seasonal flu rate. There is an FDA calculator for PPV, but the number is not hard to compute by hand. You'll arrive at 50% probability that a person is not sick after a positive test. That didn't prevent a local doctor from going to the parent's group on facebook and claiming that the test had very little chance of false positives. Assuming vaccinated are not tested, the numbers for unvaccinated will be inflated.
US numbers could be skewed by testing. I live in Illinois; quite a few of employers require weekly testing for unvaccinated only. Same with high schools, a large percentage of students over 12 yrs old are vaccinated in Chicago and northern suburbs, and only unvaccinated kids are subject to weekly testing. These tests have a low PPV (positive predictive value, P(sick | positive test) ), the one in schools around me is about 50%.
This is absolutely correct and I am also in Ilinois.
So to give a bit more color... one of the school tests has a false positive rate of 1% and false negative of 3%. Assume 1% of population is sick at any given time. That number is a bit larger than the seasonal flu rate. There is an FDA calculator for PPV, but the number is not hard to compute by hand. You'll arrive at 50% probability that a person is not sick after a positive test. That didn't prevent a local doctor from going to the parent's group on facebook and claiming that the test had very little chance of false positives. Assuming vaccinated are not tested, the numbers for unvaccinated will be inflated.