One really weird thing I noticed is when they talk about the limitations they mention issues around sensitivity but there is nothing in the paper that talks about specificity issues. The combination of non-zero false positive rate, lowish real rate in the population ~1% according to the test and testing people without symptoms surely creates a problem with the results. I guess for looking at differences over time this might not be a problem because the specificity/sensitivity issues should be a constant.
One really weird thing I noticed is when they talk about the limitations they mention issues around sensitivity but there is nothing in the paper that talks about specificity issues. The combination of non-zero false positive rate, lowish real rate in the population ~1% according to the test and testing people without symptoms surely creates a problem with the results. I guess for looking at differences over time this might not be a problem because the specificity/sensitivity issues should be a constant.