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Comment by ekidd | Hacker News Reader

> fatality was highest in persons aged ≥85, ranging from 10% to 27%, followed by 3% to 11% among persons aged 65–84 years, 1% to 3% among persons aged 55-64 years, <1% among persons aged 20–54 years, and no fatalities among persons aged ≤19 years.

The problem with all of these numbers is that they assume sufficient medical care and access to an ICU.

This report here breaks down how many people need an ICU by age: https://www.statnews.com/2020/03/18/coronavirus-new-age-anal...

> In contrast, among people 20 to 44, 14% to 21% of 705 cases were admitted to hospitals and 2% to 4% to ICUs; 0.1% to 0.2% died.

If we assume that ICUs are overloaded, how many of the that 2-4% would die?

Not that this doesn't count the people who won't catch the virus because of herd immunity. There may also be some people who are immune, or who defeat the virus quickly enough to not show positive on an RNA test.

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That report just sources the same CDC report, but I think it gets some of its conclusions wrong.

It says:

>In contrast, among people 20 to 44, 14% to 21% of 705 cases were admitted to hospitals and 2% to 4% to ICUs; 0.1% to 0.2% died.

But the CDC report indicates that 12% total (of all cases) are known to have been hospitalized, and of that number, 20% were age 20-44. So that would mean that (0.12*.2=) 2.4% of people total were 20-44 and in the hospital. Now 29% of all cases were in that age group, so that would mean for the 20-44 age group there was a (2.4/29=)8.3% chance of hospitalization.

Maybe I misunderstood something there, but I think I'm right.

I think you're reading it right, assuming they do know the ages of all people hospitalized, and the total cases with known+unknown age have close to the same distribution as the cases with known age. 102 hospitalizations / 1226 total cases = 8.3%.

A huge remaining unknown is how many people were infected but not tested, which would tend to reduce that 8.3% but perhaps not to a negligible level.

Actually that's not correct. The CDC study has a lot of null data and there's some very inconsistent excluding of data while calculating these numbers. I had to work with it in Excel for awhile to reconstruct the approximate raw numbers.

Out of 4226 cases

2449 have known ages

705 were 20 to 44

~488 of that age have a known age and hospitalization status

~101 of that age were hospitalized

~14 of that age went to ICU

(14.3% of the known # of cases for that age and 20.8% of the known # of cases for that age with a known hospitalization status were hospitalized)

Check this against Figure 2 in the CDC study and you will see where the StatNews article is pulling its data from.

This is very sobering information. Please stay safe!

It says "Among 508 (12%) patients". 508 is 12% of the whole 4226, not just the 2449 with known ages. 20% (102) of those 508 were aged 20-44.

It's not known how many of the 4226 were aged 22-44, but if it's roughly the same as the 29% of known ages, that would be 1226.

102/1226 is 8.3%.

I hate to say it, but it seems the table at the bottom is overestimating the proportion of hospitalizations by ignoring 1777 patients who have an age even if it's unknown, instead of making an estimate for them.

The reason that the unknown ages were excluded from Figure 2 is because the hospitalization status is also unknown. You assumed that 0 of the unknown cases were hospitalized. Instead, you could also assume that hospitalization rates for the unknown cases are roughly the same as for the known cases. If you do that you actually get the higher of the 2 numbers in Figure 2's range. So for the 20-44 age group, that's 20.3%. If you instead assume that people with a known age, but an unknown hospitalization status were not hospitalized, then you get he lower number in the range, 14.3%.

It's a very fair point that any of these assumptions could be inflating the rates. There are a whole bunch of other factors around asymptomatic, what the eventual outcome will be in the cases that are early-stage and who gets the limited number of tests in the USA that makes it currently impossible to know the true infection fatality rate or infection hospitalization rate.

I see, you're right. What I wrongly assumed was that they were receiving spotty data about overall cases but more thorough data about cases leading to hospitalization.

I also just noticed the age brackets for the 508 known hospitalizations only add up to about 91%, so apparently 9% of those are also unknown age.

It's too bad they didn't publish this in a live form so we could see how it changes as more data comes in. Maybe they will do a follow-up using the same methods at some point.

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