3 ms·

No they can't. You can browse my comment history for why. Tldr we'd need to see much higher positive rates among the viral tests to support that theory, and we

No they can't. You can browse my comment history for why. Tldr we'd need to see much higher positive rates among the viral tests to support that theory, and we don't.

alkonaut 7y ago
I don’t understand. Not from your comment history either. What’s the problem disqualifying all studies? The Stockholm one is the one I’m most familiar with. It used a test with specificity over 98%. Predictive power depends on the prevalence, but as the floor of immunity you can use any PCR study for active infection. In the case of Stockholm there was 2.5% active infection over a month before the sero study that showed 10%. Obviously if a poor test with 85% or 90% specificity is used and you have low prevalence then you get a poor result. But if you can peg the floor of the prevalence at several percent and use an accurate test then what’s making the results useless? But even disregarding sero studies, you can draw some conclusions of immunity from death numbers. E.g if assuming a 0.5% IFR with 1600 dead in 2100000 you would have 15% immunity (assuming everyone infected is immune of course). IFRs so high that they yield under 5% immune (basically IFR over 1.5%) aren’t consistent with observation.
- joshuamorton 7y ago
  > 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%.

No they can't. You can browse my comment history for why. Tldr we'd need to see much higher positive rates among the viral tests to support that theory, and we don't.

alkonaut 7y ago

I don’t understand. Not from your comment history either. What’s the problem disqualifying all studies? The Stockholm one is the one I’m most familiar with. It used a test with specificity over 98%. Predictive power depends on the prevalence, but as the floor of immunity you can use any PCR study for active infection. In the case of Stockholm there was 2.5% active infection over a month before the sero study that showed 10%. Obviously if a poor test with 85% or 90% specificity is used and you have low prevalence then you get a poor result. But if you can peg the floor of the prevalence at several percent and use an accurate test then what’s making the results useless? But even disregarding sero studies, you can draw some conclusions of immunity from death numbers. E.g if assuming a 0.5% IFR with 1600 dead in 2100000 you would have 15% immunity (assuming everyone infected is immune of course). IFRs so high that they yield under 5% immune (basically IFR over 1.5%) aren’t consistent with observation.

joshuamorton 7y ago
> 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%.