3 ms·

> IFRs so high that they yield under 5% immune (basically IFR over 1.5%) aren’t consistent with observation. But they are. The IFR in places like China, South

> IFRs so high that they yield under 5% immune (basically IFR over 1.5%) aren’t consistent with observation. But they are. The IFR in places like China, South Korea, and NZ that have things mostly under control at this point, the CFR is consistently above 2% (and as high as 5%), and those places are and were doing significant viral testing, so wouldn't have missed 50% or 150% of the infected. So a CFR of 2% or 1.5% isn't unreasonable (unless you're relying on sero studies as "observation"). Unless you're assuming that there's a huge swath of people (like the significant majority) of Covid-19 cases that are entirely asymptomatic (and we don't have any reason to believe this, we have upper bounds on pre-symptomatic cases at like 50% from randomized viral presence studies, and the asymptomatic numbers should be notably lower), the IFR and CFR should be reasonably close, in places that have things under control and that makes 1.5% IFR more likely than .5%. > In the case of Stockholm there was 2.5% active infection over a month before the sero study that showed 10%. Source for this? Sweden has 26,322 confirmed cases today. You're saying that 24000 of those were confirmed in Stockholm well over a month ago?

alkonaut 7y ago
These are sampled PCR tests, the 2.5% was 18 positive in a sample or something like that. (https://www.folkhalsomyndigheten.se/contentassets/7bd5627f82a84590bc2992784234b88b/forekomsten-covid-19-region-stockholm-26-mars3-april-2020.pdf https://www.folkhalsomyndigheten.se/contentassets/7bd5627f82...) The same high specificity sero test that estimated 10% in the Stockholm pop., found 20% with antibodies among hospital staff in one hospital (https://lakartidningen.se/aktuellt/nyheter/2020/04/en-av-fem-pa-danderyd-har-haft-covid-19/ https://lakartidningen.se/aktuellt/nyheter/2020/04/en-av-fem...) > Unless you're assuming that there's a huge swath of people (like the significant majority) of Covid-19 cases that are entirely asymptomatic I'm not. 50% sounds reasonable. But in Sweden, only people who are ill enough to be admitted to hospital have been tested so far (especially around the time of the earlier studies - now it's expanding to more general testing) and other than those it has been mostly hospital staff. So the missing number is all asymptomatic AND all the cases that aren't severe enough to require emergency care. And that's a significant number. I thought there was a broad consensus now that is centering in on IFR of 0.3% in many places while others seem to have higher numbers like 0.5% or 0.8%. I haven’t seen many reports that suggest over 1%. CFR doesn’t really make any sense if you only ever confirm a fraction of the cases.
- joshuamorton 7y ago
  > These are sampled PCR tests, the 2.5% was 18 positive in a sample or something like that. (https://www.folkhalsomyndigheten.se/contentassets/7bd5627f82... https://www.folkhalsomyndigheten.se/contentassets/7bd5627f82...) > But in Sweden, only people who are ill enough to be admitted to hospital have been tested so far (especially around the time of the earlier studies - now it's expanding to more general testing) and other than those it has been mostly hospital staff. So the missing number is all asymptomatic AND all the cases that aren't severe enough to require emergency care. And that's a significant number. Right, but I'm not talking about sweden, I'm talking about places that were doing more significant testing. > The same high specificity zero test found 20% with antibodies among hospital staff in one hospital This would be unsurprising. There have been studies showing that certain at risk groups have very high prevalence (meat packers, homeless, etc.). These can't really be generalized across the broader population. We can infer that, for example, the hospitalization rate in NYC and San Francisco and Stockholm will be similar per-case, and per fatality, and draw conclusions from there. Those conclusions don't lead to 10 or 20% of the population infected anywhere. They might lead to 5% infected in the worst hit areas (NYC, Lombardy, etc.). Edit: I take this back partially: Stockholm apparently could reasonably be hit as hard as NYC at the moment, so it could also be at a 5% infection rate. Sweden as a whole almost certainly isn't though. > I thought there was a broad consensus now that is centering in on IFR of 0.3% in many places while others seem to have higher numbers like 0.5% or 0.8%. I haven’t seen many reports that suggest over 1%. CFR doesn’t really make any sense if you only ever confirm a fraction of the cases. I haven't seen this. It's certainly possible, but low estimates I'd seen were .5%, centered closer to .8 or 1%.
tripletao 7y ago
Or here's a study of NYC pregnant women (who were in hospital for delivery, not for coronavirus) that found 13.7% positive by PCR (not antibodies, active infection): https://www.nejm.org/doi/full/10.1056/NEJMc2009316 https://www.nejm.org/doi/full/10.1056/NEJMc2009316 Verity et al. estimated IFR around 0.6% back in March, based on stuff like the Diamond Princess, again no antibody tests: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30243-7/fulltext https://www.thelancet.com/journals/laninf/article/PIIS1473-3... This is broadly consistent with the latest serology. NYC implies a bit worse if we divide excess deaths by antibody positives (though they haven't published their methodology as far as I know). Preprints from many European countries imply a bit better. And ~0.2% of NYC is dead from coronavirus by now. So if less than 5% of the city has had it, you think IFR is >4% there? And you think NYC's announced serology data is ~15% false positives? Even though the total positive rate--which would include both true and false positives--in serology studies in most other cities (which haven't been hit nearly as hard as NYC) is far less than 15%? This makes no sense at all. The simple explanation for Korea's high CFR is that for a disease where most countries have failed to trace ~100% of the cases, they're failing to trace about half. I think I've seen their public health authorities speculate exactly that, though I can't find the link now. Inciting public panic is a different kind of harm from inciting public complacency, but it's harm nonetheless. I urge you to correct the misinformation you've posted above. ETA: And really any single IFR is inherently misleading for this disease--the IFR climbs so steeply with age that it will vary greatly with population age structure, and with whether the disease disproportionately hits the most vulnerable (like when it spreads in nursing homes) or least (which should be our goal, since if we're unable to avoid herd immunity from recovered cases before a vaccine comes then that will cost the fewest deaths). But that's what was discussed above, so I stuck with it.
- joshuamorton 7y ago
  > And ~0.2% of NYC is dead from coronavirus by now You're confusing NYC and NY State numbers. .1% of NYC is dead from Covid at the moment. Which leads to an IFR of 2%, an IFR which falls in line, if a bit above those expected in South Korea etc. > Inciting public panic is a different kind of harm from inciting public complacency, but it's harm nonetheless. I urge you to correct the misinformation you've posted above. I agree. Can you explain what about what I've said might incite a public panic? I believe all I've said is that everything I've said can be traced back to two basic assumptions: - I think it's reasonable to believe that the IFR is among the high end of expert estimates - Naive reading of many serology studies leads to the conclusion that something like 80% of Covid cases are completely asymptomatic. This is likely untrue and believing it leads to dangerous conclusions. > Even though the total positive rate--which would include both true and false positives--in serology studies in most other cities (which haven't been hit nearly as hard as NYC) is far less than 15%? Indeed, in most it is. And then there's the study that showed 60% positive serology in a city in France, and 30% positive serology in Massachusetts. So yeah a 10% or 12% false positive rate in a serology study is completely feasible, given that the French study probably had a 40% false positive rate or something equally ridiculous.

alkonaut 7y ago

These are sampled PCR tests, the 2.5% was 18 positive in a sample or something like that. (https://www.folkhalsomyndigheten.se/contentassets/7bd5627f82a84590bc2992784234b88b/forekomsten-covid-19-region-stockholm-26-mars3-april-2020.pdf https://www.folkhalsomyndigheten.se/contentassets/7bd5627f82...) The same high specificity sero test that estimated 10% in the Stockholm pop., found 20% with antibodies among hospital staff in one hospital (https://lakartidningen.se/aktuellt/nyheter/2020/04/en-av-fem-pa-danderyd-har-haft-covid-19/ https://lakartidningen.se/aktuellt/nyheter/2020/04/en-av-fem...) > Unless you're assuming that there's a huge swath of people (like the significant majority) of Covid-19 cases that are entirely asymptomatic I'm not. 50% sounds reasonable. But in Sweden, only people who are ill enough to be admitted to hospital have been tested so far (especially around the time of the earlier studies - now it's expanding to more general testing) and other than those it has been mostly hospital staff. So the missing number is all asymptomatic AND all the cases that aren't severe enough to require emergency care. And that's a significant number. I thought there was a broad consensus now that is centering in on IFR of 0.3% in many places while others seem to have higher numbers like 0.5% or 0.8%. I haven’t seen many reports that suggest over 1%. CFR doesn’t really make any sense if you only ever confirm a fraction of the cases.

joshuamorton 7y ago
> These are sampled PCR tests, the 2.5% was 18 positive in a sample or something like that. (https://www.folkhalsomyndigheten.se/contentassets/7bd5627f82... https://www.folkhalsomyndigheten.se/contentassets/7bd5627f82...) > But in Sweden, only people who are ill enough to be admitted to hospital have been tested so far (especially around the time of the earlier studies - now it's expanding to more general testing) and other than those it has been mostly hospital staff. So the missing number is all asymptomatic AND all the cases that aren't severe enough to require emergency care. And that's a significant number. Right, but I'm not talking about sweden, I'm talking about places that were doing more significant testing. > The same high specificity zero test found 20% with antibodies among hospital staff in one hospital This would be unsurprising. There have been studies showing that certain at risk groups have very high prevalence (meat packers, homeless, etc.). These can't really be generalized across the broader population. We can infer that, for example, the hospitalization rate in NYC and San Francisco and Stockholm will be similar per-case, and per fatality, and draw conclusions from there. Those conclusions don't lead to 10 or 20% of the population infected anywhere. They might lead to 5% infected in the worst hit areas (NYC, Lombardy, etc.). Edit: I take this back partially: Stockholm apparently could reasonably be hit as hard as NYC at the moment, so it could also be at a 5% infection rate. Sweden as a whole almost certainly isn't though. > I thought there was a broad consensus now that is centering in on IFR of 0.3% in many places while others seem to have higher numbers like 0.5% or 0.8%. I haven’t seen many reports that suggest over 1%. CFR doesn’t really make any sense if you only ever confirm a fraction of the cases. I haven't seen this. It's certainly possible, but low estimates I'd seen were .5%, centered closer to .8 or 1%.

tripletao 7y ago

Or here's a study of NYC pregnant women (who were in hospital for delivery, not for coronavirus) that found 13.7% positive by PCR (not antibodies, active infection): https://www.nejm.org/doi/full/10.1056/NEJMc2009316 https://www.nejm.org/doi/full/10.1056/NEJMc2009316 Verity et al. estimated IFR around 0.6% back in March, based on stuff like the Diamond Princess, again no antibody tests: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30243-7/fulltext https://www.thelancet.com/journals/laninf/article/PIIS1473-3... This is broadly consistent with the latest serology. NYC implies a bit worse if we divide excess deaths by antibody positives (though they haven't published their methodology as far as I know). Preprints from many European countries imply a bit better. And ~0.2% of NYC is dead from coronavirus by now. So if less than 5% of the city has had it, you think IFR is >4% there? And you think NYC's announced serology data is ~15% false positives? Even though the total positive rate--which would include both true and false positives--in serology studies in most other cities (which haven't been hit nearly as hard as NYC) is far less than 15%? This makes no sense at all. The simple explanation for Korea's high CFR is that for a disease where most countries have failed to trace ~100% of the cases, they're failing to trace about half. I think I've seen their public health authorities speculate exactly that, though I can't find the link now. Inciting public panic is a different kind of harm from inciting public complacency, but it's harm nonetheless. I urge you to correct the misinformation you've posted above. ETA: And really any single IFR is inherently misleading for this disease--the IFR climbs so steeply with age that it will vary greatly with population age structure, and with whether the disease disproportionately hits the most vulnerable (like when it spreads in nursing homes) or least (which should be our goal, since if we're unable to avoid herd immunity from recovered cases before a vaccine comes then that will cost the fewest deaths). But that's what was discussed above, so I stuck with it.

joshuamorton 7y ago
> And ~0.2% of NYC is dead from coronavirus by now You're confusing NYC and NY State numbers. .1% of NYC is dead from Covid at the moment. Which leads to an IFR of 2%, an IFR which falls in line, if a bit above those expected in South Korea etc. > Inciting public panic is a different kind of harm from inciting public complacency, but it's harm nonetheless. I urge you to correct the misinformation you've posted above. I agree. Can you explain what about what I've said might incite a public panic? I believe all I've said is that everything I've said can be traced back to two basic assumptions: - I think it's reasonable to believe that the IFR is among the high end of expert estimates - Naive reading of many serology studies leads to the conclusion that something like 80% of Covid cases are completely asymptomatic. This is likely untrue and believing it leads to dangerous conclusions. > Even though the total positive rate--which would include both true and false positives--in serology studies in most other cities (which haven't been hit nearly as hard as NYC) is far less than 15%? Indeed, in most it is. And then there's the study that showed 60% positive serology in a city in France, and 30% positive serology in Massachusetts. So yeah a 10% or 12% false positive rate in a serology study is completely feasible, given that the French study probably had a 40% false positive rate or something equally ridiculous.