An important characteristic of an infectious disease, particularly one caused by a unique pathogen like SARS-CoV-2, is its severity, the last word measure of which is its ability to cause death. Fatality rates help us understand the severity of a disease, identify at-risk populations, and evaluate quality of healthcare.
There are two measures accustomed assess the proportion of infected individuals with fatal outcomes. The primary is infection fatality ratio (IFR), which estimates this proportion of deaths among all infected individuals. The second is case fatality ratio (CFR), which estimates this proportion of deaths among identified confirmed cases.