3 ms·
Except that you are not picked from the whole population at large, but from a subset of it. Namely the subset that (weakly) believes they have dementia. This ch
by Phemist 11y ago
Except that you are not picked from the whole population at large, but from a subset of it. Namely the subset that (weakly) believes they have dementia. This changes the incidence rate (or likelihood function) probably by at least an order of magnitude.
- kpmah 11y agoYou're right. You have to update the probability with all the knowledge you have. Although I would say self diagnosis has a very, very high false positive rate, and if you know you're a hypochondriac that would make the probability drop, plus we don't even have a test for this that is 90% accurate. I'm not sure the difference is an order of magnitude :) I think my point stands that it doesn't make sense to test for extremely rare diseases because of a self diagnosis.