Basic Statistics PSA:
Fixating on the case fatality rate without considering incidence is myopic; this is how the mathematics breaks down.
Say we compare two countries, lets call them Sensibleland and Deludedland, both countries have populations of 1,000,000
1/n
Fixating on the case fatality rate without considering incidence is myopic; this is how the mathematics breaks down.
Say we compare two countries, lets call them Sensibleland and Deludedland, both countries have populations of 1,000,000
1/n
A disease called 2020Sucks suddenly breaks out and we want to know which country has dealt with the disease better. So we look at the case fatality rate (CFR), say Sensibleland has a CFR = 30% whereas Deludedland's CFR = 5%. Has Deluldedland handled the disease better?
2/n
2/n
Trick question, you need to know the incidence.
Say that 10% of Sensiblelands population caught 2020Sucks in a year, giving an incidence rate of 10%/year.
Out of Sensiblelands entire population, 100,000 caught the disease. Out of those 100,000, 30,000 die making Cfr= 30%
3/n
Say that 10% of Sensiblelands population caught 2020Sucks in a year, giving an incidence rate of 10%/year.
Out of Sensiblelands entire population, 100,000 caught the disease. Out of those 100,000, 30,000 die making Cfr= 30%
3/n
Deludedland on the other hand has an incidence of 100%, meaning their entire population catch 2020Sucks.
Out of the 1,000,000 who catch the disease, 5% die, making the death count 50,000.
4/n
Out of the 1,000,000 who catch the disease, 5% die, making the death count 50,000.
4/n
So despite Deludedland having a lower CFR, more people die from 2020Sucks in Deludedland compared to Sensibleland due to higher incidence rates. Despite that, the statistically semi-literate celebrate how Deludedland's low CFR means that less people are dying from 2020Sucks.
5/n
5/n
People who understand Bayesian statistics see through the BS.
6/ n
6/ n
