I've been looking at all the doom and gloom numbers associated with COVID-19. Early on there were numbers that said the sky was going to fall. Just really "hard to believe" numbers. So like a good nerd, I did my own math.
All these sites are comparing the number of deaths to number of cases on a daily basis. As a result, the number of cases are increasing at an exponential rate, but the number of deaths aren't. I believe that's because there's a certain amount of time (unknown) that it takes from the time a patient tests positive to the time that a person actually dies from it (what I refer to as Time To Death or TTD). If that TTD is for example, 8 days, there would be an 8 day lag between the number of cases testing positive and the number of deaths (it would take 8 days for people to start dying). So the number of cases will far outrun the number of deaths - which would show a continuous decrease in the % of deaths. Eventually though (if my logic is correct) at some time in the future, the number of cases will begin to flatten out (increase, but at a decreasing rate), and barring a miracle cure, the number of deaths will increase at a more rapid rate (as a % of new cases) until they catch up with the TTD delay.
I won't be surprised when we see the % of deaths start to rise for a period of time - the length of which will be defined by the length of the TTD. If the TTD is a shorter period (i.e. 3 days) that spike will come sooner. If the TTD is a longer period (i.e. 14 days) then that spike will come later. Either way, the numbers they have been writing about are wrong.
So does my theory hold water? Here's the result:
It spiked early on, but then over time it began a steady decline. I believe Italy is a great leading edge indicator. They've turned the corner - even though the daily numbers don't tell that story (today was Italy's worst day so far as deaths are concerned).
Here's the USA's numbers as of right now:
I believe these are much more accurate mortality rates. As we learn how to treat this better, these numbers will only go down IMHO.