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Comment by cozzyd | Hacker News Reader

I had the opposite conclusion. There are between 10k-15k COVID-19 associated deaths in NYC, depending on how you count (the higher rate is consistent with the excess-mortality data, I believe). That by itself produces a range of ~0.56%-0.86% if you assume 21.2 % of NYC has been infected (larger range if you allow for some error on the infection rate, obviously). Moreover, we don't know what fraction of the currently-infected who will die have already died. A reasonable guess might be 50%, which would mean that the fatality rate for NYC is somewhere between 1.1 and 1.7%.

Either way, based on NYC, 0.5% might be a hard lower bound on the all-population fatality rate (of course, maybe NYC is not a representative sample for some reason)

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0.5% comes from Cuomo’s presentation [1].

Also your 50% seems very high to me. My understanding is that 50% is about the death rate of covid patients requiring ventilation, so the overall death rate of people hospitalised for covid must be well below that.

Also if you factor this timing impact, you have the same timing impact on the denominator, i.e. people who are infected but haven't developped antibodies yet.

[1] https://youtu.be/TisDYYWJgBA?t=967

[edit] in fact for the 50%, we have an idea from Cuomo's presentation charts. The gross daily hostpitalisation rate as of 10-15 days ago was about 2000-2500 per day, and the number of death now is about 500 per day, so that suggests roughly a 20-25% death rate for hospitalised people (I am sure there must be some more precise figures somewhere).

50% is not the death rate, but the fraction of those who are an infected and have died to those who are infected and who will have died (since there is some lag between infection and death).

The death rate of those requiring ventilation in NYC is closer to 88% https://jamanetwork.com/journals/jama/fullarticle/2765184

Outside the context of this virus, for adult men, the survival rate one year after mechanical ventilation might be 30 percent: https://www.ncbi.nlm.nih.gov/pubmed/8404197/

no, the death rate for ventilated covid patients is something like 80-90%. this is based on a NYC study published yesterday.

“ Moreover, we don't know what fraction of the currently-infected who will die have already died. A reasonable guess might be 50%” I lost you at reasonable guess. Why not ~1%?

The virus takes time (2-3 weeks) to kill people, and the prevalence was presumably measured within the last week.

Therefore, we have to take out the cases that occurred in the last week or two. I would suspect that 50% is on the upper end of how much the death lag could skew the results, but 20-50% doesn't seem unreasonable.

If the mean time between infection and death is 2 weeks (Mostly true), and the virus has doubled every two weeks (True in NYC), then assuming that not a single new infection takes place starting today (Obviously not true, but this is a hypothetical), then in two weeks, you would expect to have twice the deaths that you do right now.

1% would imply an unrealistically high-fatality rate, so that can't be right.

It’s not clear what kind of antibodies they’re testing for, but it can take up to 4 weeks after infection to develop detectable levels of antibodies. It takes on average ~3 weeks after infection to die. There needs to be some time lag adjustment in your calculation, which would likely result in a lower IFR.

IMO the two effects probably about cancel each other out and we’re looking at <1% IFR for the population tested (AFAIK children weren’t included).

I guess I would assume they would have corrected for any time-lag in the result, but I have not read the study in detail

Right now it's just a press release so there's not much to read. Cuomo's statement reads to me that is just demographically adjusted though.

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