9 ms·

Adjusted Age-Specific Case Fatality Ratio During for COVID-19 in Hubei [pdf]

129 points by tomerbd 7y ago

Gys 7y ago
> We estimated the age-specific case fatality ratio (CFR) by fitting a transmission model to data from China, accounting for underreporting of cases and the time delay to death. Overall CFR among all infections was 1.6% (1.4-1.8%) and increased considerably for the elderly, highlighting the expected burden for populations with further expansion of the COVID-19 epidemic around the globe.
- wbhart 7y ago
  It's worth pointing out that this is the CFR for the virus, SARS-CoV-2 (i.e. including asymptomatic individuals). The CFR for the disease, COVID-19, is 3.3% (2.9-3.8%). I'm not sure which it is more common to report, but the 2% estimate that was used earlier in the epidemic was for the disease rather than the virus, apparently.
  - poizan42 7y ago
    The CFR rate for the disease rather than infectius agent is not really useful for anything besides inciting panic. Consider the case where a virus only shows symptoms in 0.1% of case, but is 100% fatal when it does. You could report this as NEW EPIDEMIC 100% FATAL, WE ARE ALL GONNA DIE!!! but that hardly gives a realistic picture.
    - wbhart 7y ago
      "We are all gonna die" is a statement about the mortality rate, not the case fatality rate. This paper does not deal with the mortality rate.
  - glofish 7y ago
    That CFR is not for the disease. It is for the disease that has progressed sufficiently to be recorded (noticed).
    - wbhart 7y ago
      If I am reading it correctly, that is not what the paper says. It says that it takes into account the individuals who had the disease but were not reported/recorded. Further to that, some individuals are asymptomatic which means that not only are they not reported, but they never are. They don't get the disease. It has nothing to do with how far the disease progressed in them, because they never have it.
vackosar 7y ago
Death rate: Age 0-9: 0.0094% Age 10-19: 0.022% Age 20-29: 0.091% Age 30-39: 0.18% Age 40-49: 0.4% Age 50-59: 1.3% Age 60-69: 4.6% Age 70-79: 9.8% Age 80+: 18% TL;DR dont infect ur parents as 60-69 has 1 in 21 chance of death.
- mtsr 7y ago
  Thanks for summarizing. Plenty here are going to have parents in 70-79 (like I do) or 80+. And I really don’t like those odds.
- dforrestwilson 7y ago
  Really please don’t infect _anyone_, as it increases the likelihood that someone else’s parent or grandparent will die.
- StavrosK 7y ago
  I wouldn't gamble with a 1 in 500 chance for me either.
  - kd5bjo 7y ago
    That works out to 2000 micromorts, which compares to the accumulated baseline risk over 3 months of living: https://en.m.wikipedia.org/wiki/Micromort https://en.m.wikipedia.org/wiki/Micromort
    - StavrosK 7y ago
      I still wouldn't want to get infected.
    - yread 7y ago
      Yes, bit more dangerous than BASE-jumping. No, thanks. When was the last time you did something that had 0.2% chance to kill you? Also what this number kind of glosses over is how are the survivors doing. Half of those that get ARDS have life-long consequences. There are still 20.000 active cases in China, 1 month after the epidemic peaked there. EDIT: I took BASE jumping risk from here http://www.wingsuitfly.com/risk/4572000812 http://www.wingsuitfly.com/risk/4572000812 not from the wiki reference
d4t4 7y ago
This study makes a comparison of the age distribution in reported Covid-19 cases vs. the distribution of ages in the Chinese population. I think this approach can definitely provide insight however, there’s one assumption that this study uses which will definitely bias the fatality rates being estimated. > We chose to fix to 100% the reporting rate of infected individuals that have symptoms and are aged 80 and more, and estimate the reporting rates in other age groups relatively to that of older individuals. If further data, coming from a study in the general population, shows that this assumption is violated, this would lead to an overestimation of the CFR in our study. I find it hard to believe that 100% of cases in individuals over 80 will be reported. It seems like any estimation of fatality rate at this time is going to be guesswork without more systematic sampling of the population. I’m not trying to minimize the danger of Covid-19. It seems like caution to prevent further spread is absolutely necessary.
mhb 7y ago
Presumably age as a factor is used because it's easy to measure, but it would be nice to know the effect of comorbidity. For example, comparing otherwise healthy 60 year olds to otherwise healthy 30 year olds.
- bob33212 7y ago
  And a breakdown into specific medical factors. Diabetes, Smoker, AIDS, cancer, flu.
svara 7y ago
This model is nice in principle, but its results depend crucially on what is ultimately an educated guess of the reporting rate of symptomatic cases. This parameter can be found experimentally by testing for antibodies against the virus in a random sample of the population. This has not been done so far. As long as that's true, CFR estimates will be quite uncertain. Also really interesting in this context is how Germany is looking more and more like a huge outlier in terms of fatality. Almost 1000 cases and 0 deaths so far. Sure, that may still change, but the outbreak has been going on for a while there already.
- bjourne 7y ago
  But can you know that Germany is an outlier? Germany likely has a higher reporting rate than China so its numbers should be closer to the truth.
  - svara 7y ago
    Exactly my point ;)
  - chefkoch 7y ago
    Germany is not testing nearly enough people. There are lots of reports of people with legitimate concerns that did not find a way to get tested. Northern italy is like 2 hours by car and each weekend thousands drive there for a short trip.
    - svara 7y ago
      Something needs to explain the difference though between 939:0 in Germany and, e.g., 949:11 in France. Maybe the diagnoses in Germany are closer in time to infections? That would still point to a higher reporting rate in Germany vs. other countries.
      - usrusr 7y ago
        France has had a continuous epidemic since early on, but Germany successfully contained the first outbreak (thanks to one phone call from China at the right time), then it was all quiet for a while and only now Germany is catching up in case count, at a very high speed. This means that Frances, with a comparable total, has far more cases that are old enough to have already played out negatively.
chrononaut 7y ago
How much do we think healthcare and hospital stability was implicitly factored into this study given that the data was focused in Hubei? Meaning, if hospitals had to turn away patients, one would think the death rate would increase. If hospitals could receive all patients, one would presume the death rate would be lower? It's clear health care systems get overloaded even with a low symptomatic case saturation per capita.[0] Related to this, what I haven't seen mentioned or discussed extensively is not only would the fatality rate increase for Covid-19 cases if hospitals are overloaded, but I would assume the fatality rate for _all other needs_ of a hospital would also increase. Does anyone know this has been assessed? (e.g., did Hubei see a notable increase in non-Covid-19 related deaths during this period?) [0] https://www.aljazeera.com/news/2020/03/coronavirus-wreaks-havoc-italy-tests-limits-health-system-200307112350888.html https://www.aljazeera.com/news/2020/03/coronavirus-wreaks-ha...
- empath75 7y ago
  Italy is seeing similar numbers if not worse.
- DocSavage 7y ago
  I think we're seeing a small case study of this in the nursing home in Washington. Out of 120 residents, 13 are dead and have been identified with COVID-19. There were 11 more who died at the nursing home since Feb 19 and haven't been tested, but they said on average 3-6 residents die per month. I think the nursing home scenario is probably a worst case given both age and underlying health concerns (unlike elderly still living in their own home or with their families). Given the Seattle area medical infrastructure, this fatality rate can't be explained by overloading of our facilities. I really disliked Fauci's comments that "the risk is low" to the American population, pointing to the rate of infection. He hedges this with some hand waving that it could change at any moment. I thought it was irresponsible to say the risk is low when they hadn't done any real testing and we've actually got outbreaks like in Kirkland. Regarding his comment that the WHO fatality rate is too high because of asymptomatic population and the denominator in reality is much higher. Fine. But he doesn't acknowledge that the numerator might be much higher as well. How many 80+ year olds, especially those with preexisting conditions, die and are assumed to have just passed from old age and the preexisting conditions. It is a characteristic of this virus that the people getting killed are the most likely ones not to raise huge red flags early. So in general, I would've preferred him to not say anything about risk until we actually get more numbers and real testing within our population. The average fatality rate hides the fact that this virus is very dangerous to the elderly.
kaiabwpdjqn 7y ago
Death rates aside, it looks like younger people are less likely to even get the disease (not especially surprising). If you exclude the really young people, even the 30 year olds would likely be under represented (I think). One implication of this may be that societies with more socially engaged older people will be more vulnerable to this. E.g. countries where people who serve as frequent touch points to strangers like frontline retail jobs are likely to be older might do worse in this circumstance.
- paulryanrogers 7y ago
  Are we sure they don't get it, or are just asymptomatic in the short term. Chicken pox is a thing parents commonly seek out for their kids around here. But in the long term the vaccine is still better at reducing long term consequences. (Got it intentionally as a child then again [unintentionally] as a teen. Had some nerve damage since. Not looking forward to shingles.)
  - kaiabwpdjqn 7y ago
    That was my point of confusion on the charts for symptomatic people. I’m assuming that the relatively high rates of non symptomatic individuals implies they’re testing people without symptoms in a somewhat random sample style
SubiculumCode 7y ago
So all our presidential candidates (sitting or otherwise) have some relatively bad odds.
- dougmwne 7y ago
  Iran's leadership is experiencing this right now.
watertom 7y ago
Until the dust settles on COVID-19 this is all speculation. I have a question about the Spanish Flu. Most reliable literature CDC, WHO lost the CFR for the Spanish Flu at 2.5. This makes no sense to me. The Spanish flu killed between 50-100 Million people, 3-6% of the world’s population, it infected about 500 Million people, so why isn’t the CFR between 10-20%?
- maxerickson 7y ago
  How does the proximate cause of death factor into the CFR? In 1918, most of the deaths were from secondary infections: https://www.nih.gov/news-events/news-releases/bacterial-pneumonia-caused-most-deaths-1918-influenza-pandemic https://www.nih.gov/news-events/news-releases/bacterial-pneu...
DataDrivenMD 7y ago
As with any statistical analysis based on a sample of the total population, there will be biases (as many have already noted). That being said, these results reflect what we’ve seen in the real world in places like Washington state, Italy, Iran, and even S. Korea. More to the point: these data underscore the importance of following the advice of public health officials. It’s fine to have an intellectual discussion about the merits of the study, but let’s make sure that we keep our eye on the prize. Each of us has a responsibility to do our part in protecting our parents, friends, and coworkers. TL;DR - This study suggests that many of us on HN will be fine no matter what. But it also demonstrates that, if left unchecked, it’s possible (if not probable) that many of us will be grieving the loss of someone we love. There’s no need to panic, and there’s no room for those who seek to be dismissive, flippant, or ignorant. Everyone will be fine if each of us focuses on doing the right thing.
acoderhasnoname 7y ago
why is the CDC not telling us where are the suspected cases and how many out there??? Do they even know that number??
longtimegoogler 7y ago
As someone who is atopic but not asthmatic, I am especially concerned. My guess is that atopic and asthmatic indivdiduals might be at higher risk. As someone in their forties, I can't think of any other potential risk that I am aware of where I might have a 1 in 50 chance of dying if I catch this (assuming an elevated risk) given that I am relatively health otherwise.
portlander12345 7y ago
Do we have enough information to do this kind estimate for serious or critical symptoms, rather than just deaths? What are the chances of somebody in a given age bracket needing breathing support?

129 points by tomerbd 7y ago

Gys 7y ago

> We estimated the age-specific case fatality ratio (CFR) by fitting a transmission model to data from China, accounting for underreporting of cases and the time delay to death. Overall CFR among all infections was 1.6% (1.4-1.8%) and increased considerably for the elderly, highlighting the expected burden for populations with further expansion of the COVID-19 epidemic around the globe.

wbhart 7y ago
It's worth pointing out that this is the CFR for the virus, SARS-CoV-2 (i.e. including asymptomatic individuals). The CFR for the disease, COVID-19, is 3.3% (2.9-3.8%). I'm not sure which it is more common to report, but the 2% estimate that was used earlier in the epidemic was for the disease rather than the virus, apparently.
- poizan42 7y ago
  The CFR rate for the disease rather than infectius agent is not really useful for anything besides inciting panic. Consider the case where a virus only shows symptoms in 0.1% of case, but is 100% fatal when it does. You could report this as NEW EPIDEMIC 100% FATAL, WE ARE ALL GONNA DIE!!! but that hardly gives a realistic picture.
  - wbhart 7y ago
    "We are all gonna die" is a statement about the mortality rate, not the case fatality rate. This paper does not deal with the mortality rate.
- glofish 7y ago
  That CFR is not for the disease. It is for the disease that has progressed sufficiently to be recorded (noticed).
  - wbhart 7y ago
    If I am reading it correctly, that is not what the paper says. It says that it takes into account the individuals who had the disease but were not reported/recorded. Further to that, some individuals are asymptomatic which means that not only are they not reported, but they never are. They don't get the disease. It has nothing to do with how far the disease progressed in them, because they never have it.

vackosar 7y ago

Death rate: Age 0-9: 0.0094% Age 10-19: 0.022% Age 20-29: 0.091% Age 30-39: 0.18% Age 40-49: 0.4% Age 50-59: 1.3% Age 60-69: 4.6% Age 70-79: 9.8% Age 80+: 18% TL;DR dont infect ur parents as 60-69 has 1 in 21 chance of death.

mtsr 7y ago
Thanks for summarizing. Plenty here are going to have parents in 70-79 (like I do) or 80+. And I really don’t like those odds.
dforrestwilson 7y ago
Really please don’t infect _anyone_, as it increases the likelihood that someone else’s parent or grandparent will die.
StavrosK 7y ago
I wouldn't gamble with a 1 in 500 chance for me either.
- kd5bjo 7y ago
  That works out to 2000 micromorts, which compares to the accumulated baseline risk over 3 months of living: https://en.m.wikipedia.org/wiki/Micromort https://en.m.wikipedia.org/wiki/Micromort
  - StavrosK 7y ago
    I still wouldn't want to get infected.
  - yread 7y ago
    Yes, bit more dangerous than BASE-jumping. No, thanks. When was the last time you did something that had 0.2% chance to kill you? Also what this number kind of glosses over is how are the survivors doing. Half of those that get ARDS have life-long consequences. There are still 20.000 active cases in China, 1 month after the epidemic peaked there. EDIT: I took BASE jumping risk from here http://www.wingsuitfly.com/risk/4572000812 http://www.wingsuitfly.com/risk/4572000812 not from the wiki reference

d4t4 7y ago

This study makes a comparison of the age distribution in reported Covid-19 cases vs. the distribution of ages in the Chinese population. I think this approach can definitely provide insight however, there’s one assumption that this study uses which will definitely bias the fatality rates being estimated. > We chose to fix to 100% the reporting rate of infected individuals that have symptoms and are aged 80 and more, and estimate the reporting rates in other age groups relatively to that of older individuals. If further data, coming from a study in the general population, shows that this assumption is violated, this would lead to an overestimation of the CFR in our study. I find it hard to believe that 100% of cases in individuals over 80 will be reported. It seems like any estimation of fatality rate at this time is going to be guesswork without more systematic sampling of the population. I’m not trying to minimize the danger of Covid-19. It seems like caution to prevent further spread is absolutely necessary.

mhb 7y ago

Presumably age as a factor is used because it's easy to measure, but it would be nice to know the effect of comorbidity. For example, comparing otherwise healthy 60 year olds to otherwise healthy 30 year olds.

bob33212 7y ago
And a breakdown into specific medical factors. Diabetes, Smoker, AIDS, cancer, flu.

svara 7y ago

This model is nice in principle, but its results depend crucially on what is ultimately an educated guess of the reporting rate of symptomatic cases. This parameter can be found experimentally by testing for antibodies against the virus in a random sample of the population. This has not been done so far. As long as that's true, CFR estimates will be quite uncertain. Also really interesting in this context is how Germany is looking more and more like a huge outlier in terms of fatality. Almost 1000 cases and 0 deaths so far. Sure, that may still change, but the outbreak has been going on for a while there already.

bjourne 7y ago
But can you know that Germany is an outlier? Germany likely has a higher reporting rate than China so its numbers should be closer to the truth.
- svara 7y ago
  Exactly my point ;)
- chefkoch 7y ago
  Germany is not testing nearly enough people. There are lots of reports of people with legitimate concerns that did not find a way to get tested. Northern italy is like 2 hours by car and each weekend thousands drive there for a short trip.
  - svara 7y ago
    Something needs to explain the difference though between 939:0 in Germany and, e.g., 949:11 in France. Maybe the diagnoses in Germany are closer in time to infections? That would still point to a higher reporting rate in Germany vs. other countries.
    - usrusr 7y ago
      France has had a continuous epidemic since early on, but Germany successfully contained the first outbreak (thanks to one phone call from China at the right time), then it was all quiet for a while and only now Germany is catching up in case count, at a very high speed. This means that Frances, with a comparable total, has far more cases that are old enough to have already played out negatively.

chrononaut 7y ago

How much do we think healthcare and hospital stability was implicitly factored into this study given that the data was focused in Hubei? Meaning, if hospitals had to turn away patients, one would think the death rate would increase. If hospitals could receive all patients, one would presume the death rate would be lower? It's clear health care systems get overloaded even with a low symptomatic case saturation per capita.[0] Related to this, what I haven't seen mentioned or discussed extensively is not only would the fatality rate increase for Covid-19 cases if hospitals are overloaded, but I would assume the fatality rate for _all other needs_ of a hospital would also increase. Does anyone know this has been assessed? (e.g., did Hubei see a notable increase in non-Covid-19 related deaths during this period?) [0] https://www.aljazeera.com/news/2020/03/coronavirus-wreaks-havoc-italy-tests-limits-health-system-200307112350888.html https://www.aljazeera.com/news/2020/03/coronavirus-wreaks-ha...

empath75 7y ago
Italy is seeing similar numbers if not worse.
DocSavage 7y ago
I think we're seeing a small case study of this in the nursing home in Washington. Out of 120 residents, 13 are dead and have been identified with COVID-19. There were 11 more who died at the nursing home since Feb 19 and haven't been tested, but they said on average 3-6 residents die per month. I think the nursing home scenario is probably a worst case given both age and underlying health concerns (unlike elderly still living in their own home or with their families). Given the Seattle area medical infrastructure, this fatality rate can't be explained by overloading of our facilities. I really disliked Fauci's comments that "the risk is low" to the American population, pointing to the rate of infection. He hedges this with some hand waving that it could change at any moment. I thought it was irresponsible to say the risk is low when they hadn't done any real testing and we've actually got outbreaks like in Kirkland. Regarding his comment that the WHO fatality rate is too high because of asymptomatic population and the denominator in reality is much higher. Fine. But he doesn't acknowledge that the numerator might be much higher as well. How many 80+ year olds, especially those with preexisting conditions, die and are assumed to have just passed from old age and the preexisting conditions. It is a characteristic of this virus that the people getting killed are the most likely ones not to raise huge red flags early. So in general, I would've preferred him to not say anything about risk until we actually get more numbers and real testing within our population. The average fatality rate hides the fact that this virus is very dangerous to the elderly.

kaiabwpdjqn 7y ago

Death rates aside, it looks like younger people are less likely to even get the disease (not especially surprising). If you exclude the really young people, even the 30 year olds would likely be under represented (I think). One implication of this may be that societies with more socially engaged older people will be more vulnerable to this. E.g. countries where people who serve as frequent touch points to strangers like frontline retail jobs are likely to be older might do worse in this circumstance.

paulryanrogers 7y ago
Are we sure they don't get it, or are just asymptomatic in the short term. Chicken pox is a thing parents commonly seek out for their kids around here. But in the long term the vaccine is still better at reducing long term consequences. (Got it intentionally as a child then again [unintentionally] as a teen. Had some nerve damage since. Not looking forward to shingles.)
- kaiabwpdjqn 7y ago
  That was my point of confusion on the charts for symptomatic people. I’m assuming that the relatively high rates of non symptomatic individuals implies they’re testing people without symptoms in a somewhat random sample style

SubiculumCode 7y ago

So all our presidential candidates (sitting or otherwise) have some relatively bad odds.

dougmwne 7y ago
Iran's leadership is experiencing this right now.

watertom 7y ago

Until the dust settles on COVID-19 this is all speculation. I have a question about the Spanish Flu. Most reliable literature CDC, WHO lost the CFR for the Spanish Flu at 2.5. This makes no sense to me. The Spanish flu killed between 50-100 Million people, 3-6% of the world’s population, it infected about 500 Million people, so why isn’t the CFR between 10-20%?

maxerickson 7y ago
How does the proximate cause of death factor into the CFR? In 1918, most of the deaths were from secondary infections: https://www.nih.gov/news-events/news-releases/bacterial-pneumonia-caused-most-deaths-1918-influenza-pandemic https://www.nih.gov/news-events/news-releases/bacterial-pneu...

DataDrivenMD 7y ago

As with any statistical analysis based on a sample of the total population, there will be biases (as many have already noted). That being said, these results reflect what we’ve seen in the real world in places like Washington state, Italy, Iran, and even S. Korea. More to the point: these data underscore the importance of following the advice of public health officials. It’s fine to have an intellectual discussion about the merits of the study, but let’s make sure that we keep our eye on the prize. Each of us has a responsibility to do our part in protecting our parents, friends, and coworkers. TL;DR - This study suggests that many of us on HN will be fine no matter what. But it also demonstrates that, if left unchecked, it’s possible (if not probable) that many of us will be grieving the loss of someone we love. There’s no need to panic, and there’s no room for those who seek to be dismissive, flippant, or ignorant. Everyone will be fine if each of us focuses on doing the right thing.

acoderhasnoname 7y ago

why is the CDC not telling us where are the suspected cases and how many out there??? Do they even know that number??

longtimegoogler 7y ago

As someone who is atopic but not asthmatic, I am especially concerned. My guess is that atopic and asthmatic indivdiduals might be at higher risk. As someone in their forties, I can't think of any other potential risk that I am aware of where I might have a 1 in 50 chance of dying if I catch this (assuming an elevated risk) given that I am relatively health otherwise.

portlander12345 7y ago

Do we have enough information to do this kind estimate for serious or critical symptoms, rather than just deaths? What are the chances of somebody in a given age bracket needing breathing support?