4 ms·

> Serious cases and mortality (2%) will be adjusted downwards safely in the coming weeks, as the detection of mild cases increases. There are factors that coul

> Serious cases and mortality (2%) will be adjusted downwards safely in the coming weeks, as the detection of mild cases increases. There are factors that could move that number in both directions. Yes, presumably there are many mild cases that haven't been counted. But unfortunately coronavirus deaths are probably also undercounted -- for example, https://www.washingtonpost.com/world/as-families-tell-of-pneumonia-like-deaths-in-wuhan-some-wonder-if-china-virus-count-is-too-low/2020/01/22/0f50b1e6-3d07-11ea-971f-4ce4f94494b4_story.html https://www.washingtonpost.com/world/as-families-tell-of-pne... This point I'm not sure about, because it seems bizarre that everyone would make such an obvious mistake, but: as far as I can tell, the death rate is simply calculated as [current total of recorded deaths] / [current total of recorded cases]. But when the fatal cases take quite a long time to kill (from what I've read, it tends to take a week or so from the onset of symptoms for them to become severe, and up to another two weeks for death to occur -- see https://www.straitstimes.com/asia/east-asia/reporters-notebook-life-and-death-in-a-wuhan-coronavirus-icu https://www.straitstimes.com/asia/east-asia/reporters-notebo...) and the total number of cases is rising dramatically, surely that skews the figure toward a significant underestimate?

gamblor956 7y ago
For example, using the simple methodology, SARS' death rate was only about 3%, and that was the number most media used during the outbreak. But years after the epidemic ended, once researchers had greater access to medical records, the death was determined to be 10-15%, or roughly 3-5x higher than originally reported. In the cases of NCV, there is already significant evidence of under reporting of fatalities by Chinese authorities in Wuhan (some sources suggest that up to 90% of NCV deaths in China may be unreported). And as the cruise ship stuck outside of Japan demonstrates, the virus may be far more virulent (i.e., contagious) than previously thought.
- gamblor956 7y ago
  Followup: https://www.nytimes.com/2020/02/12/world/asia/china-coronavirus-cases.html https://www.nytimes.com/2020/02/12/world/asia/china-coronavi... China just changed how it classifies NCV cases to reduce the number of cases by eliminating those who are infected but not symptomatic meaning the numbers are even less reliable than they were before. The problem with this is that a number of the superspreaders, like the British fellow that infected 11 other people, and the passenger that infected the cruise ship quarantined in Japan, were not symptomatic when they were infecting others.
Filligree 7y ago
It does, but that's a known factor which all medical professionals are aware of. The true number is unknowable until the epidemic is over, so they give the best number we've got in full knowledge that the numerical value will be wrong.
- retsibsi 7y ago
  This seems dangerous, if it leads to unwarranted complacency among those who take the number seriously. Do you know the rationale behind reporting a number known to be skewed in this way -- is the idea that it is roughly canceled out by other factors (e.g. the number of undiagnosed mild cases) that push toward an overestimate?
  - Filligree 7y ago
    That is a factor, but bluntly put, the ones who are reporting this single number aren't medical professionals. Those might still use it in conversation amongst each other, sure, but any actual analysis will be based on far more data than a single number. Fundamentally this is the press trying to boil things down to a double soundbite. As usual. The case fatality ratio is literally defined as deaths over cases, and that's not useless, but it isn't something you should spend much time thinking about either. Reality is always more complex than any single number. Probably you want to know something like "What are the odds of dying if I'm infected" -- that's a different parameter entirely.
    - retsibsi 7y ago
      I'm not so much worried about how the experts interpret this number behind closed doors, but how everyone else reacts to it. This thread began with someone confidently saying that the 2% death rate will decline as we get better data, and using that to argue against the cancellation of the MWC. I've also seen about a million thinkpieces and social media posts telling us that we're crazy to worry about this virus because the flu is so much worse -- and while they're mostly focusing on the fact that the current number of cases is small compared to seasonal flu, they might not be so dismissive if they knew that 2% could be a significant underestimate of the mortality rate. And I suspect that many (most?) countries' quarantine and related policies are affected by public opinion, rather than being a pure function of expert advice.

gamblor956 7y ago

For example, using the simple methodology, SARS' death rate was only about 3%, and that was the number most media used during the outbreak. But years after the epidemic ended, once researchers had greater access to medical records, the death was determined to be 10-15%, or roughly 3-5x higher than originally reported. In the cases of NCV, there is already significant evidence of under reporting of fatalities by Chinese authorities in Wuhan (some sources suggest that up to 90% of NCV deaths in China may be unreported). And as the cruise ship stuck outside of Japan demonstrates, the virus may be far more virulent (i.e., contagious) than previously thought.

gamblor956 7y ago
Followup: https://www.nytimes.com/2020/02/12/world/asia/china-coronavirus-cases.html https://www.nytimes.com/2020/02/12/world/asia/china-coronavi... China just changed how it classifies NCV cases to reduce the number of cases by eliminating those who are infected but not symptomatic meaning the numbers are even less reliable than they were before. The problem with this is that a number of the superspreaders, like the British fellow that infected 11 other people, and the passenger that infected the cruise ship quarantined in Japan, were not symptomatic when they were infecting others.

Filligree 7y ago

It does, but that's a known factor which all medical professionals are aware of. The true number is unknowable until the epidemic is over, so they give the best number we've got in full knowledge that the numerical value will be wrong.

retsibsi 7y ago
This seems dangerous, if it leads to unwarranted complacency among those who take the number seriously. Do you know the rationale behind reporting a number known to be skewed in this way -- is the idea that it is roughly canceled out by other factors (e.g. the number of undiagnosed mild cases) that push toward an overestimate?
- Filligree 7y ago
  That is a factor, but bluntly put, the ones who are reporting this single number aren't medical professionals. Those might still use it in conversation amongst each other, sure, but any actual analysis will be based on far more data than a single number. Fundamentally this is the press trying to boil things down to a double soundbite. As usual. The case fatality ratio is literally defined as deaths over cases, and that's not useless, but it isn't something you should spend much time thinking about either. Reality is always more complex than any single number. Probably you want to know something like "What are the odds of dying if I'm infected" -- that's a different parameter entirely.
  - retsibsi 7y ago
    I'm not so much worried about how the experts interpret this number behind closed doors, but how everyone else reacts to it. This thread began with someone confidently saying that the 2% death rate will decline as we get better data, and using that to argue against the cancellation of the MWC. I've also seen about a million thinkpieces and social media posts telling us that we're crazy to worry about this virus because the flu is so much worse -- and while they're mostly focusing on the fact that the current number of cases is small compared to seasonal flu, they might not be so dismissive if they knew that 2% could be a significant underestimate of the mortality rate. And I suspect that many (most?) countries' quarantine and related policies are affected by public opinion, rather than being a pure function of expert advice.