Mortality rate
Say it: mor-TAL-ih-tee RAYT
A mortality rate is how often death occurs in a defined population over a set period, usually given as deaths per 1,000 or 100,000 people.
Also: death rate, mortality rates
Definition
What is a mortality rate?
A mortality rate, or death rate, measures how frequently deaths occur in a defined population over a stated period, most often a year. The number of deaths is divided by the size of the population, usually estimated at the middle of the period, and multiplied by a round number such as 1,000 or 100,000 so results are easy to compare. The crude mortality rate counts deaths from all causes across a whole population.
More specific versions narrow the count. A cause-specific rate includes deaths from one cause, such as heart disease, and an age-specific rate looks at a single age group. The infant mortality rate, deaths before age one per 1,000 live births, is widely used to compare the health of nations because it reflects maternal health, sanitation and access to care. Strictly it is a ratio, since its denominator is births rather than the population alive.
Because older people die at higher rates, crude rates can mislead when populations differ in age. A region with many retirees may have a higher crude rate than a younger one even if every age group fares better there. Age-adjusted, or age-standardized, rates remove this effect. A mortality rate differs from a case fatality rate, which counts deaths only among people who have a particular disease.
Word parts
Where does the term “mortality rate” come from?
- mort-
- deathLatin mors, mortis
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Related
Terms that go with it
- Case fatality rateThe case fatality rate is the share of people diagnosed with a particular disease who die of it, a basic measure of how severe that disease is.
- MorbidityMorbidity is the state of having a disease, injury or disability, and also the amount of illness in a population, measured by incidence and prevalence.
- Life expectancyLife expectancy is the average number of further years people of a given age would live if current death rates at each age stayed the same.
- IncidenceIncidence is the number of new cases of a disease that arise in a population at risk during a specified period of time.
- EpidemiologyEpidemiology is the study of how often diseases and other health events occur in populations, what causes them and how they can be controlled.
- Public healthPublic health is the science and practice of preventing disease and injury and promoting health across whole communities rather than individual patients.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- CDC Principles of Epidemiology, Lesson 3 Section 3: Mortality Frequency Measures
- NCI Dictionary of Cancer Terms: mortality
- OpenStax Microbiology, 16.1 The Language of Epidemiologists
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