What’s the chance of dying if you get COVID-19?
Exactly how deadly is COVID really? Some people have suggested it’s the same as the flu. Others have said that it’s much more serious. Unfortunately, recent studies confirmed that COVID is definitely more deadly than the flu, but maybe not as deadly as we initially thought.
Case fatality rate, or CFR, is the number of people who die from COVID divided by the number of confirmed and reported cases. CFR therefore changes based on testing; you have to be tested to be a confirmed and reported case of COVID.
Infection fatality rate, or IFR is the number of people who die from COVID divided by the number of people thought to be infected. The true IFR does not vary based on testing. Of course, it’s impossible to know the true number of people infected. Some people don’t get tested or get tested too soon, so we don’t have an official record of their infection. Thus, calculating the IFR depends on estimating the number of people in the county who are infected.
The case fatality rate, in almost all diseases, is higher than the infection fatality rate. At the beginning of the pandemic, we had limited information and could only calculate the CFR. Now, with more information and models, we can calculate the IFR. The headlines you read most likely haven’t captured the difference between these two estimates.
Putting together data from multiple countries, doctors now estimate that the IFR for COVID is 0.68%. That means that about 1 in every 150 people who catch COVID die from it. However, younger people are at lower risk of dying and older people are at much higher risk. Another study put together data from around the world and found that the IFR is very low for children and younger adults (2 in 100,000 at age 10, and 10 in 100,000 at age 25). But the IFR increases to 4 in 1,000 at age 55 (0.4%), 14 in 1,000 at age 65 (1.4%), 46 in 1,000 at age 75 (4.6%), and 150, in 1,000 at age 85 (15%).
Last update: March 25, 2021, 9:05am ET
Science review: GSN, HAY