Currently, and especially in this COVID-19 outbreak, the death rate divulged during an outbreak is calculated as:

total # of deaths ÷ total # of cases

What bugs me is that the 2nd term of the expression (which include ongoing cases) follows a geometric progression over time, whereas deaths and remissions (closed cases) take, as divulged, 14 days in average to occur after diagnosis.

14 steps in a geometric progression mean a lot, and given an optimistic cases increase of 10% a day (in the COVID-19 outbreak it's much higher), this gives a 280% increase in that period.

And since the total # of deaths originate from a total # of cases that is around 14 days older, what's the meaning of the expression?

If the expression tries to reflect the chance of dying after getting diagnosed positive for the virus, it is completely misleading, since the 1st term and the 2nd term reflect different points in time regarding the diagnosis, and the 2nd is much higher (280% in the example) than it should be. Thus the correct expression should be

total # of deaths ÷ total # of closed cases

because both terms refer semantically to the same universe of cases (deaths + remissions = closed cases).

Both expressions will inevitably converge to the same result (after the outbreak all cases will be closed cases), but the latter will get to the actual rate much faster, because the former has an implicit time delay.

So WTH is the former being used?

total # of deaths ÷ total # of cases

What bugs me is that the 2nd term of the expression (which include ongoing cases) follows a geometric progression over time, whereas deaths and remissions (closed cases) take, as divulged, 14 days in average to occur after diagnosis.

14 steps in a geometric progression mean a lot, and given an optimistic cases increase of 10% a day (in the COVID-19 outbreak it's much higher), this gives a 280% increase in that period.

And since the total # of deaths originate from a total # of cases that is around 14 days older, what's the meaning of the expression?

If the expression tries to reflect the chance of dying after getting diagnosed positive for the virus, it is completely misleading, since the 1st term and the 2nd term reflect different points in time regarding the diagnosis, and the 2nd is much higher (280% in the example) than it should be. Thus the correct expression should be

total # of deaths ÷ total # of closed cases

because both terms refer semantically to the same universe of cases (deaths + remissions = closed cases).

Both expressions will inevitably converge to the same result (after the outbreak all cases will be closed cases), but the latter will get to the actual rate much faster, because the former has an implicit time delay.

So WTH is the former being used?

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