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Antibody tests are not as accurate as RT-PCR, but the sensitivity that was observed here was 91% and 99% specificity when compared to confirmed COVID cases. I j
by Medicalidiot 6y ago
Antibody tests are not as accurate as RT-PCR, but the sensitivity that was observed here was 91% and 99% specificity when compared to confirmed COVID cases. I just want to point out that these researchers are using the corrects tests to do this.
- jacquesm 6y agoThey use the correct tests, but they use them on a group that isn't even close to a random sample of the population, which is what you'd need to do to get to their conclusion.
- Medicalidiot 6y agoI'm not going to comment on that because I have a basic understanding of public health and epidemiology on the diagnostic side of things. Why do you think that this isn't a "good" random sample?
- mlyle 6y agoIt's not a random sample; it's a convenience sample of people who responded to Facebook ads.
- Medicalidiot 6y agoWhat about Facebook ads doesn't mean that they're an adequate sample? Is there a confounding factor that you have in mind?
- mlyle 6y agoMany confounding factors. Socioeconomic factors that can't be fixed with stratified sampling (access to transportation, usage of Facebook, etc.. conversely the willingness of a $10 amazon gift card to motivate people to participate will vary). People who are concerned about possible past exposure to COVID-19 may have a different probability to respond. Of course, the bigger issue is that we can't rule out that the antibody tests have a false positive rate that can explain the whole result. We need serology tests in places with a higher positive rate to know. Basically, 50 positive results out of 3330 is a really small signal. Just a small false positive rate or sampling issue could explain all the positive results.