Updated May 11, 2013.

Definition:

A mortality rate represents the risk of dying from a given disease or exposure (for example, to radiation or harmful chemicals), assessed for a given population over a specific period of time.

According to the US National Library of Medicine, a mortality rate is usually calculated using the following formula:

10ⁿ (Number of deaths during a specific period) / (Number of people at risk of dying during the same period)

n is usually 3 or 5, indicating death rates per 1,000, or 100,000 people.

Example: The US National Institutes of Health (NIH) reports that in 1975, the mortality rate for cancer was 199 deaths for every 100,000 persons. By 2007, the mortality rate was 178 deaths for every 100,000 persons.

• How is a mortality rate different from mortality?
• More on Mortality Rate Data

<sub>Source:

Cancer. US National Institutes of Health Fact Sheet. Accessed February 22, 2013.
http://report.nih.gov/nihfactsheets/viewfactsheet.aspx?csid=75

International Union of Pure and Applied Chemistry (IUPAC) Glossary of Terms used in Toxicology. US Department of Health and Human Services Public Information Sheet. Accessed February 22, 2013.
http://sis.nlm.nih.gov/enviro/iupacglossary/glossarym.html</sub>

Also Known As: Death rate