4 ms·

The fatality rate may be 3.4% and the r0 may be 2.6 to 3.4 but it is unlikely that both are true at the same time. It depends on your assumption of undiagnosed

The fatality rate may be 3.4% and the r0 may be 2.6 to 3.4 but it is unlikely that both are true at the same time. It depends on your assumption of undiagnosed cases. We don’t know how many of those there are. But suppose you assume that all the diagnosed cases are all the cases (impossible but for the sake of the statistical argument). That is to say we tested 100% of the sick people. If that were true the fatality rate would shoot up to the high end of the estimate and the r0 would plummet. It hardly spread at all, but if a patient gets it, it is more fatal. On the other hand assume that almost everyone has it but we only tested a tiny fraction. Now the r0 sky rockets and the fatality rate plummets. Put another way, there is a trade off between the two and it is unlikely to be on the upper end of the estimates for both. What this author is saying is that it hardly spreads at all but the fatality rate is high. I.e we tested many of the cases.

wahern 7y ago
Pretty sure the fatality rate is based on the number of patients who present themselves to a doctor. I've seen estimates of influenza fatality rate of 0.2%, which corresponds with the ~61000 deaths over ~20700000 medical visits for the 2017-2018 influenza season documented here: https://www.cdc.gov/flu/about/burden/2017-2018.htm https://www.cdc.gov/flu/about/burden/2017-2018.htm The fatality rate would obviously decline with a larger denominator which includes total infected. But so would the rate for influenza. It still seems to remain the case that this virus is ~10x deadlier than the flu, unless it has a far greater r0. The possibility of variants (type-S and type-L) mentioned elsethread makes things more complicated, though.
- mrandish 7y ago
  > Pretty sure the fatality rate is based on the number of patients who present themselves to a doctor. In an ideal world that would be true, however we know that in early Wuhan they were mostly only testing people who were already hospitalized with "pneumonia symptoms" due to having limited kits and staff. Pneumonia symptoms how the most serious cases advance after going through flu symptoms. I read one analysis of the Wuhan data that showed 91% of everyone they tested had pneumonia. This changed later but a lot of the stats we're looking at are from papers with data only through the end of Jan. Almost every country has different criteria for testing a patient and you can't become a "case" until you have a positive test. The U.S. has changed testing policy three times in the last week.
- omarhaneef 7y ago
  > Pretty sure the fatality rate is based on the number of patients who present themselves to a doctor. I don’t think this is right. I believe it’s based on an estimate. Your own numbers bear me out. The flu death rate is estimated to be around 0.1% and we can come to that number by a division here: “ The overall burden of influenza for the 2017-2018 season was an estimated 45 million influenza illnesses, 21 million influenza-associated medical visits, 810,000 influenza-related hospitalizations, and 61,000 influenza-associated deaths” So 61/45000 = .14%
  - eveningcoffee 7y ago
    Actually 21 million or 45 million does not make much difference. There will be still order of magnitude between influenza and covid-19 (CFR 0.2% vs 3.4%, and mind you, 3.4% is an early estimate and subject to change in the situation where new cases are still coming in and people are still dying, if you observed then CFR for covid-19 was around 2% when it was rapidly growing in China and did rise to current level when the new cases started to slow down; many people warned that it will be much higher actually but these people were hushed down; you have to use your own analytical mind to choose what is more closer to the truth).
  - deleted 7y ago
    [deleted]

wahern 7y ago

Pretty sure the fatality rate is based on the number of patients who present themselves to a doctor. I've seen estimates of influenza fatality rate of 0.2%, which corresponds with the ~61000 deaths over ~20700000 medical visits for the 2017-2018 influenza season documented here: https://www.cdc.gov/flu/about/burden/2017-2018.htm https://www.cdc.gov/flu/about/burden/2017-2018.htm The fatality rate would obviously decline with a larger denominator which includes total infected. But so would the rate for influenza. It still seems to remain the case that this virus is ~10x deadlier than the flu, unless it has a far greater r0. The possibility of variants (type-S and type-L) mentioned elsethread makes things more complicated, though.

mrandish 7y ago
> Pretty sure the fatality rate is based on the number of patients who present themselves to a doctor. In an ideal world that would be true, however we know that in early Wuhan they were mostly only testing people who were already hospitalized with "pneumonia symptoms" due to having limited kits and staff. Pneumonia symptoms how the most serious cases advance after going through flu symptoms. I read one analysis of the Wuhan data that showed 91% of everyone they tested had pneumonia. This changed later but a lot of the stats we're looking at are from papers with data only through the end of Jan. Almost every country has different criteria for testing a patient and you can't become a "case" until you have a positive test. The U.S. has changed testing policy three times in the last week.
omarhaneef 7y ago
> Pretty sure the fatality rate is based on the number of patients who present themselves to a doctor. I don’t think this is right. I believe it’s based on an estimate. Your own numbers bear me out. The flu death rate is estimated to be around 0.1% and we can come to that number by a division here: “ The overall burden of influenza for the 2017-2018 season was an estimated 45 million influenza illnesses, 21 million influenza-associated medical visits, 810,000 influenza-related hospitalizations, and 61,000 influenza-associated deaths” So 61/45000 = .14%
- eveningcoffee 7y ago
  Actually 21 million or 45 million does not make much difference. There will be still order of magnitude between influenza and covid-19 (CFR 0.2% vs 3.4%, and mind you, 3.4% is an early estimate and subject to change in the situation where new cases are still coming in and people are still dying, if you observed then CFR for covid-19 was around 2% when it was rapidly growing in China and did rise to current level when the new cases started to slow down; many people warned that it will be much higher actually but these people were hushed down; you have to use your own analytical mind to choose what is more closer to the truth).
- deleted 7y ago
  [deleted]