And same question for a positive test: if you get a positive and then retest and get a negative, do you have a sense of how much of an overall update you should make? I’ve been treating that as ‘well, it was probably a false positive then’, but multiplying the two updates together would imply it’s probably legit?
Yeah, based on the Cochrane paper I’d interpret “one positive result and one negative result” as an overall update towards having COVID. In general, both rapid antigen tests and NAATs are more sensitive than they are specific (more likely to return false negatives than false positives.)
Though also see the “Caveats about infectiousness” section, which suggests that NAATs have a much higher false positive rate for detecting infectiousness than they do for detecting illness. I don’t have numbers for this, unfortunately, so I’m not sure if 1 positive NAAT + 1 negative NAAT is overall an update in favor or away from infectiousness.
And same question for a positive test: if you get a positive and then retest and get a negative, do you have a sense of how much of an overall update you should make? I’ve been treating that as ‘well, it was probably a false positive then’, but multiplying the two updates together would imply it’s probably legit?
Yeah, based on the Cochrane paper I’d interpret “one positive result and one negative result” as an overall update towards having COVID. In general, both rapid antigen tests and NAATs are more sensitive than they are specific (more likely to return false negatives than false positives.)
Though also see the “Caveats about infectiousness” section, which suggests that NAATs have a much higher false positive rate for detecting infectiousness than they do for detecting illness. I don’t have numbers for this, unfortunately, so I’m not sure if 1 positive NAAT + 1 negative NAAT is overall an update in favor or away from infectiousness.