How is the fatality rate for COVID-19 calculated



– How is the <1% fatality rate reported in some media for COVID-19 calculated?

Looking at the numbers as of now, there have been just over 88,000 cases and 3,001 deaths in the COVID-19 outbreak so far. This gives a fatality rate of around 3.3%. When looking at cases which have been closed (either recovered or died), the rate is closer to 7%. This seems hard to reconcile with the media reports saying the rate is below 1% and at worse maybe 2%?

In: Mathematics

Rate is calculated regionally, with the number of dead im china or taiwan you should expect more infected, which makes some believe they change their numbers

Number of deaths / number of infected people

So if you have 100 infected and 1 dead, thats a rate of 1/100 – or 1%

It is thought that most of the infected presents with none or small symptoms and therefore the patients does not seek medical attention and does not get counted. This is based on instances where they tested a select group of people that are suspected infected where it is shown that a lot of them tests positive and even spreads the infections on without having noticed any symptoms. If that is representative of the large infection centers then there are likely hundreds of thousands of people who have been infected without being part of the official statistics. The death rate is therefore likely much lower then the raw data would suggest.

For what is probably a number of reasons, the case fatality rate (# of confirmed dead due to disease / # of confirmed with the disease * 100) in Hubei province is higher than in many other locations — both in China and around the world.

The (# confirmed dead due to disease / # of confirmed recovered from the disease * 100) rate has been dropping for the past month and a half, and is NOT the case fatality rate that people are talking about.

There are likely a number of mild or asymptomatic cases that never go to the hospital and get confirmed, so they never become **cases** and are not included in the case fatality rate. So the true fatality rate is thought to be lower than the 2-4% or so that you get from just dividing the numbers.

All of that said — CFR is something people estimate while the outbreak is going on, and calculate firmly after it is over. So what you see in the media is an estimate.