Monday, April 20, 2020

Real COVID-19 Death Rate

In my last post, we did research on COVID-19 death rate based on the ratio between the number of deaths and the number of confirmed cases. However, this method is inherently flawed. Some infected people did not show up at a hospital or a testing station to get tested. As a result, the death rate is exaggerated.

Blood antibody tests on randomly sampled residents in Santa Clara, California in early April shows that the number of people infected is 55 to 85 times more than confirmed cases (https://www.cnn.com/2020/04/17/health/santa-clara-coronavirus-infections-study/index.html). Thus, the real death rate for people who infected with coronavirus is between 0.1% and 0.17% which are similar to that of flu.

We use the following charts to illustrate two ways of calculating death rates.

COVID-19 Death Rate (Flawed) = Number of Deaths/ Number of Confirmed Cases

COVID-19 Death Rate (Real) = Number of Deaths/Number of Infected
As we can see, the chance of COVID-19 bullet hitting the bullseye, i.e., causing death, is much slimmer that appears based on confirmed cases alone.

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