5 ms·

So, I'm not getting why selection bias would matter here. If they are counting the total number of participants who were positive for the antibodies, and this

So, I'm not getting why selection bias would matter here. If they are counting the total number of participants who were positive for the antibodies, and this number was out of the total number of residents in the county, big deal. Why would they ask all the healthy people to come get tested? Just assume that all the untested people are negative for the antibodies. Otherwise you would get a higher infection rate count, which would of course result in a lower mortality rate for the disease.

SpicyLemonZest 7y ago
You're misunderstanding the methodology. They tested a sample and multiplied to get the overall infection rate, under the assumption that their sample was representative.
PierceJoy 7y ago
If the sample was biased, then the results cannot be generalized to the whole population. The purpose of this study was not to find positive cases to treat, it was to estimate the prevalence in the general population.
MiroF 7y ago
Sure, but that's not at all how the sampling was done. Just read the article!