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> The real world results, as measured, showed a 0.3% false positive rate. Try as I did, I can't find a source for this claim. The best I could find was[1] whic

by nanis 5y ago

> The real world results, as measured, showed a 0.3% false positive rate. Try as I did, I can't find a source for this claim. The best I could find was[1] which seems to indicate a 1.1% false positive rate for people without symptoms (keep in mind my argument is against widespread, unconditional testing). PCR results in the real world seem to vary a lot, but a 3% false positive rate seems appropriate. > 17 people quarantined from a single positive test. That "17" is a linear constant. That is a faulty argument. You are assuming total costs of a trace/quarantine regime are linear in the number of people prevented from participating in society and productive activities. [1]: https://www.gavi.org/vaccineswork/how-likely-positive-lateral-flow-test-covid-19-be-wrong https://www.gavi.org/vaccineswork/how-likely-positive-latera...

regularfry 5y ago
First page of google searching for "lft false positive rate" gives me https://www.ox.ac.uk/news/2020-11-11-oxford-university-and-phe-confirm-lateral-flow-tests-show-high-specificity-and-are https://www.ox.ac.uk/news/2020-11-11-oxford-university-and-p... : The specificity of the test was recorded as 99.68% - the overall false positive rate was 0.32%, although this was lowered to 0.06% in a lab setting. > PCR results in the real world seem to vary a lot, but a 3% false positive rate seems appropriate. Not to me. Again, first page of google: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/methodologies/covid19infectionsurveypilotmethodsandfurtherinformation#test-sensitivity-and-specificity https://www.ons.gov.uk/peoplepopulationandcommunity/healthan... puts an _upper_ bound on the PCR false positive rate of 0.08%, and that would require all the positives in that survey to have been false. And that's a real-world result across 208,730 samples. But given the existence of LFTs and how cheap and immediate they are, I don't think anyone's talking about population-wide PCR testing anyway. > You are assuming total costs of a trace/quarantine regime are linear in the number of people prevented from participating in society and productive activities. For the proportion of the population removed at any given time? As close to linear as makes no difference, yes. Is your argument that there's a quadratic factor in network effects? You haven't explained what your cost model actually is. For your argument to work you need those costs to follow an exponential curve, and there's just no mechanism for that to happen.

by nanis 5y ago

regularfry 5y ago

First page of google searching for "lft false positive rate" gives me https://www.ox.ac.uk/news/2020-11-11-oxford-university-and-phe-confirm-lateral-flow-tests-show-high-specificity-and-are https://www.ox.ac.uk/news/2020-11-11-oxford-university-and-p... : The specificity of the test was recorded as 99.68% - the overall false positive rate was 0.32%, although this was lowered to 0.06% in a lab setting. > PCR results in the real world seem to vary a lot, but a 3% false positive rate seems appropriate. Not to me. Again, first page of google: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/methodologies/covid19infectionsurveypilotmethodsandfurtherinformation#test-sensitivity-and-specificity https://www.ons.gov.uk/peoplepopulationandcommunity/healthan... puts an _upper_ bound on the PCR false positive rate of 0.08%, and that would require all the positives in that survey to have been false. And that's a real-world result across 208,730 samples. But given the existence of LFTs and how cheap and immediate they are, I don't think anyone's talking about population-wide PCR testing anyway. > You are assuming total costs of a trace/quarantine regime are linear in the number of people prevented from participating in society and productive activities. For the proportion of the population removed at any given time? As close to linear as makes no difference, yes. Is your argument that there's a quadratic factor in network effects? You haven't explained what your cost model actually is. For your argument to work you need those costs to follow an exponential curve, and there's just no mechanism for that to happen.