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Covid 19 virus
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drussell:

--- Quote from: not1xor1 on March 25, 2020, 09:16:11 am ---SK South Korea death vs amount of cases is increasing and currently 1.379% (126/9137*100)
--- End quote ---

Of course that number is going up.  You're conveniently just totally ignoring the 5281 cases that don't have a known outcome yet.  (Well, you're not ignoring them, per se, you're actually just lumping them all in with the known recovered to calculate a meaningless percentage.)

Of the first 3856 cases in South Korea where there is an outcome, 126/3856 = 3.27%

You cannot just assume that the other active 5281 cases all miraculously recover with no more deaths.  While an epidemic is ongoing, calculating a crude CFR that way is disingenuous at best, dangerous at worst if it makes people complacent.  There is a multi-week delay between the detection of most cases and an outcome.  During exponential growth in spread it takes time for the outcome numbers to track the new cases.  You must look at the trends for forecasting, not the absolute numbers, and when calculating numbers you need to look at what set of patients actually represents your known outcomes.

If you look at the US' number right now and calculate a crude CFR, it would be 802/55243 = 1.45%
Some media has been continuing to report this kind of number, saying things like look, it's only 10x worse than the flu....  But it appears to actually be potentially closer to another order of magnitude higher.

It is still far too early in the US' outbreak to make any conclusions as to what the actual CFR there will be in any particular region.  With only 354 declared "recovered" so far nationwide, the naive calculation based on actual outcomes is currently just as meaningless, (other than to watch trends, of course.)  We know it will not end up being the current 69.4% once more cases have known outcomes.
Stray Electron:

--- Quote from: Mr. Scram on March 24, 2020, 08:41:13 pm ---
An infected person tugging at a virus soaked mask sounds like a great idea.

--- End quote ---

  An infected person out in public without a mask and sneezing on everyone sounds like a worse thing to me.

  The WHO acts like no one outside of the medical system has ever used a mask before and is clueless. There are tens of millions of people in this country alone that have been taught how to use masks in the fire departments, police departments, military, industrial welders and many other occupations.

    In every previous medical situation, the medical professionals have recommended using masks but now that the hospitals are short, suddenly they're telling everyone else NOT to use one and that suddenly they're ineffective.  Seriously?  Or are you just trying to keep all of the masks for yourself and your medical colleagues?

   I'll be happy for the rest of you not to wear a mask since it will leave more for me but given the choice I will wear one.

   A personal note, when the last polio epidemic went around in about 1960, my mother was was of the few trained nurses in our area and I well remember her going around to houses that had been quarantined to check on the people and to take them food and medicine and she always wore a mask.  No one debated the effectiveness of the masks,  you just wore one, no questions asked.
drussell:
The case fatality rate (CFR) represents the proportion of cases who eventually die from a disease.
Once an epidemic has ended, it can simply be calculated with the formula: deaths / cases.

While an epidemic is still ongoing, as it is the case with the current novel coronavirus outbreak, this formula is, at the very least, "naïve" and can be "misleading if, at the time of analysis, the outcome is unknown for a non negligible proportion of patients."

In other words, current deaths belong to a total case figure of the past, not to the current case figure in which the outcome (recovery or death) of a proportion (the most recent cases) hasn't yet been determined.

The correct formula, therefore, would appear to be:

CFR = deaths at day.x / cases at day.x-{T}
(where T = average time period from case confirmation to death)

This would constitute a fair attempt to use values for cases and deaths belonging to the same group of patients.

One issue can be that of determining whether there is enough data to estimate T with any precision, but it is certainly not T = 0 (what is implicitly used when applying the formula current deaths / current cases to determine CFR during an ongoing outbreak).

...or, you can use the known outcomes like I did for rough current calculations, knowing that accuracy will improve as more outcomes are known, etc. by just using the CFR = deaths / (deaths + recovered)

In any case, simply using deaths / total cases is essentially currently meaningless given the high rate of daily new infections and the lengthy time period before there is a known outcome.
Mr. Scram:

--- Quote from: Stray Electron on March 25, 2020, 02:39:47 pm ---  An infected person out in public without a mask and sneezing on everyone sounds like a worse thing to me.

  The WHO acts like no one outside of the medical system has ever used a mask before and is clueless. There are tens of millions of people in this country alone that have been taught how to use masks in the fire departments, police departments, military, industrial welders and many other occupations.

    In every previous medical situation, the medical professionals have recommended using masks but now that the hospitals are short, suddenly they're telling everyone else NOT to use one and that suddenly they're ineffective.  Seriously?  Or are you just trying to keep all of the masks for yourself and your medical colleagues?

   I'll be happy for the rest of you not to wear a mask since it will leave more for me but given the choice I will wear one.

   A personal note, when the last polio epidemic went around in about 1960, my mother was was of the few trained nurses in our area and I well remember her going around to houses that had been quarantined to check on the people and to take them food and medicine and she always wore a mask.  No one debated the effectiveness of the masks,  you just wore one, no questions asked.

--- End quote ---
At this point we're really going in circles. I'll refer to the previous n pages for the how and why on masks. Though it surprises me how intent people are on this "you're just keeping the masks for yourself" conspiracy. Resource management is important in the sense that masks shouldn't be wasted on ineffectual deployment, but the suggestion they're just out to hoard them for doctors is another thing. Let's please not use 1960s healthcare as any kind of example for our current situation. We don't have all the answers now so they definitely didn't have them back then.
edavid:

--- Quote from: nctnico on March 25, 2020, 01:52:40 pm ---
--- Quote from: dunkemhigh on March 25, 2020, 12:51:18 pm ---In general it's not a case of knowing better (or not). If one's intuition suggests one thing and expert advice suggests another, shouldn't one try to find out why there is that difference?

--- End quote ---
This is exactly what the WHO does! They look at the research and information from all the experts from different countries and base the information they supply on that. As usual truth is what the majority thinks is right but I rather follow advice resulting from balancing many different opinions than that of a limited group of people (government advisors included).

--- End quote ---

But doesn't e.g. South Korea have its own WHO equivalent?  Why did they come to the opposite conclusion from WHO regarding masks?

Also, you could argue that the Chinese health authorities know more about the problem than anyone, and they seem to be very pro-mask.   Again, why?

WHO has failed to establish a consensus or to make a solid case for their anti-mask statements.
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