Death Rates Are Hard to Calculate:
One of the points that has been noted by many astute epidemiologists is that we can never know the true death rate (total # dead divided by the total # of individuals infected) from any infectious epidemic or pandemic. The problem is that unless we were to test the entire population for the infectious disease of concern, we will not be able to know the true total number of individuals who are infected.
In the case of COVID-19, we only know the total number of confirmed cases of infection and total number of dead attributed to the virus (see the Johns Hopkins site).
When we calculate the death rate, we will get an artificially high number. If everyone was tested, we would likely see a much higher number of infected individuals than we know now due to the limited testing that has been done to date.
Additionally, each city, state and country will have different age populations, varying degrees of health and lifestyle, environmental issues, genetic and epigenetic differences, access to high quality health care, etc. Each of these variables factor into the probability of dying from diseases, including COVID-19.
Another factor that is very important is the ability of the local healthcare system to treat the most severely ill patients. Under the best of circumstances (no hospital overcrowding, adequate ICU beds and ventilators, etc.), many of the severely ill patients will be able to be treated and survive. If however, the growth rate of the cases shoots up to much the number of severely ill patients will overwhelm the capacity of the healthcare system to treat them and many who would normally survive will die. This is why we are trying to flatten the curve of infections, so we can minimize the numbers of cases presenting to hospitals at once.
Recognizing these variables exist, we can only roughly estimate death rates in a population.
Calculator to Determine Your Risk of Dying From a COVID-19 Infection (Version 2):
I have taken the published data from China and built this into a model to help predict the probability of dying from COVID-19.
To calculate your probability of dying from a COVID-19 infection, you will need to know the total # of confirmed infections and the total # of deaths in your locale. I recommend using your country #’s (see the Johns Hopkins Site) instead of your city or state, to increase the statistical power of the model.