Sure. Per yesterday's paper, there have been 15185 cases and 834 deaths in WA. That would be a CFR of about 5%.
Now, it says the cases are 33% above sixty, and the deaths are 91% above sixty. So that would be a CFR of 758/5011, 15%.
Contrast with below sixty. Which comes to a CFR of about .7%.
If I go with just under twenty, the paper doesn't give me enough data to calculate. They are 4% of the cases, but don't even get listed in the deaths breakdown.
Under forty, the rate is about 1.5%.
And note that more testing can drive down these numbers. But it's unlikely to do so for the elderly.
You're neglecting to include asymptomatic infections which have been theorized to be up to 80% of the infected.
So you have to add (x * 34 million, where x equals some percentage of asymptomatic infections) to your infection count....if you want to be accurate which I'm assuming that's not your priority.
This offers real estimates of the actual IFR (the likelihood of death if you have the virus in your system).
I'll refer you to table 3
The average HNer is going to likely be in the 0-54 demographic. Their IFR is anywhere from 0.004% to 0.23%.
The case fatality ratio you cite has a number of problems. Firstly, it's not true that the 'current' COVID fatality rate is 1/50. To make such a claim you need to define 'current'. You are citing the entire case fatality rate over the last year and a half. And even then, you're overstating it, since it's 1.8% by most estimates.
A current rate would mean taking a smaller window starting from today and determining the CFR. Given that cases are currently going up while deaths are flat, the current CFR is going to be lower than the global CFR you cited.
CFR is always higher, because most people with COVID will not notice they have it [1]. Thus, we need scientific modeling to determine the number.
Moreover, I am not arguing that vulnerable populations do not exist. Merely that the death rates are so non-uniformly distributed, that it really doesn't make sense to have a uniform policy on all age groups / background conditions. The data tell a lot different story.
[1] From the study: The exponential pattern of our age-specific IFR estimates is qualitatively similar to that of case fatality rates (CFRs). However, the relative magnitudes are systematically different, reflecting the extent to which asymptomatic or mildly symptomatic cases are much more common in younger adults than in middle-aged and older adults. For example, the ratio of CFR to IFR is about 15:1 for ages 30–49, about 7:1 for ages 50–69, and about 5:1 for ages 70–79 years
The US has 622K fatalities on 37M cases, which is a 1.68% CFR (and is an undercount, because some current cases that will be fatalities aren't yet.) Of course, CFR isn't a constant, it varies with current healthcare overload and the lethality of different strains, among other factors.
The population-wide total IFR could be as low as 0.26% but it would depend heavily on the demographics of the people infected.
If you infect 100 people under the age of 40 your IFR will likely be much lower than even 0.26%. If just 10 of those 100 are over 80 then it’s a totally different story.
Not all diseases have such a high spread in the mortality rate versus age as COVID, which spans effectively 0%-20%. It makes discussions on the average IFR less useful than they might otherwise be.
Even apart from undercounting of case #s, we know that the # of severe cases is 5% upper bound which is much more likely to be accurate and the deaths are a fraction of that so I would bet on the number being on the lower end than the higher end. Even a 1-2% mortality rate is fairly substantial tho -- 5-10x as deadly as flu.
The case fatality rate is the number of deaths divided by the number of known cases (positive tests).
What you are looking for is the IFR (infection fatality rate) which is not known, because of the number of infections in the 10-19 population which were asymptomatic or too mild to be tested.
It’s extremely telling, for example, that 99.9% of fatalities in Italy as of two days ago were 50+. Surely that is not because no one under 50 was infected, particularly since the younger population is more likely to be congregating at bars and clubs.
I’m happy to throw away karma to call out anyone multiplying a naive CFR by a population number every time. It’s totally incorrect to do that.
Those numbers aren't terribly useful since so many cases are mild or even asymptomatic. Most organizations are estimating 2-3% mortality, and are quick to point out that this is probably an overestimation due to the lack of testing in asymptomatic individuals.
Basically we are counting every case severe enough to cause death, but only some of the cases that aren't very severe, and that latter group is already a much bigger piece of the pie even among confirmed cases.
Again, the current CFR as calculated by the WHO is a mathematical artifact. I trust that they're accurately reporting the numbers they measured, and agree that dividing their death count by their case count yields 3.4%, but I don't agree (and don't think they said) that this is an accurate estimate of how deadly the virus is likely to be.
That assumes the death rate is actually 1%. In the hypothetical where 40%+ have been infected, I think it’s be safe to assume the death rate might be lower than we suspect it is.
1% might be the case fatality rate, but it's likely at least an order of magnitude higher than the real mortality rate. With estimates of asymptomatic / minor symptoms people above 80%, most infections are not being recorded as cases.
Right. Really this study is just confirming (with higher error bars than we'd like) what we already strongly suspected.
Note that as others are pointing out, that 0.5% isn't really extrapolated correctly. The tested case deaths are looking like they're only 70% of the total or so. Also using a current death count with contemporary infection counts is a mismatch, because it forgets that ~35% of the people currently in the hospital won't ever leave, which is about 5k more deaths.
So a better calibrated CFR might be 1% or so, which is even closer to the range we've all been assuming.
The ABS clearly sets out their method for calculating CFR, which is covid deaths divided by confirmed infections.
Yes, that is only a proxy for the overall all infection fatality rate. However, given the contact tracing, testing, and medical systems have been quite robust in Australia, it shouldn't be too far off the mark.
Furthermore, the 3% figure only applies to the population as a whole. According to the ABS, CFR climbs to over 30% for people 80 and over. Similarly, a recent American study found it to be about 21% [1].
So, back to the original point, it should be very easy to find a mortality signal in a RCT, which included that cohort.
We've had nearly 3 million cases with over 130k fatalities. If the numbers are being grossly underreported, then it's certainly possible the mortality rate is < 1%, but given the numbers we have now, our mortality rate is closer to 4.5%.
This article does a better job than most, but I think still only half-asses the thought process necessary to logically reason about COVID.
The naive or “known” CFR is the fatality rate to-date divided by the number of positive tests to date.
For example, China at one point decided to consider a large number of people as positive cases based on purely clinical symptoms because they didn’t have the test capacity or specificity to definitively diagnose them. Which is why their case count gapped up one day.
The CFR after all cases have concluded is an upper bound on the IFR. There seems to be no true consensus on the percentage of asymptomatic or very mild cases which would not seek treatment or even testing. This number (which is basically unknowable during an outbreak) is a multiplier on the case count, and acts to reduce the true IFR.
Lastly, as we’ve seen quite clearly... How bad it is depends almost entirely upon the person, or at a higher level, the demographics of the people who are infected.
Italy as of March 11;
> Of the patients who died, 42·2% were aged 80–89 years, 32·4% were aged 70–79 years, 8·4% were aged 60–69 years, and 2·8% were aged 50–59 years (those aged >90 years made up 14·1%). The male to female ratio is 80% to 20% with an older median age for women (83·4 years for women vs 79·9 years for men).
Likewise, the outbreak in a WA nursing home was devastating to an elderly population where they would see 5-10 patients die in an average month.
IMO the path forward is either successful containment—which seems extremely unlikely given the transmission characteristics, but apparently China was able to do it? But where you constantly have to be watching for pockets of reemergence and clamp them down.
Or, if we can keep the virus away from high-risk populations while it spreads “like a flu” through the majority of the population, then you will see herd immunity kick in which ultimately works like a vaccinated population to prevent further outbreak and protect the at-risk population from ever becoming infected.
The 1-3% is an average among all age groups. You clearly have not looked at the data. For example, in Italy the CFR is somewhere around 14% for elderly. Everyone else is lower such that the nominal death rate, being an average among all groups,.has been consistently running around 8%.
Obviously when this matures that rate will go lower because the denominator will grow but the denominator that people care about is the one we have now: who is sick enough to need a test because if I get sick, and thus become part of that denominator, the current rate gives me a good picture of my chances. Was the parent comment slightly hyperbolic, maybe. But you are way underselling the seriousness of this disease and the rationality of being scared of it.
Now, it says the cases are 33% above sixty, and the deaths are 91% above sixty. So that would be a CFR of 758/5011, 15%.
Contrast with below sixty. Which comes to a CFR of about .7%.
If I go with just under twenty, the paper doesn't give me enough data to calculate. They are 4% of the cases, but don't even get listed in the deaths breakdown.
Under forty, the rate is about 1.5%.
And note that more testing can drive down these numbers. But it's unlikely to do so for the elderly.
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