Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of deaths per 1,000 individuals per year; thus, a mortality rate of 9.5 (out of 1,000) in a population of 1,000 would mean 9.5 deaths per year in that entire population, or 0.95% out of the total. It is distinct from "morbidity", a term used to refer to either the prevalence or incidence of a disease, and also from the incidence rate (the number of newly appearing cases of the disease per unit of time).
Related measures of mortality
Other specific measures of mortality include:
- Crude death rate – the total number of deaths per year per 1,000 people. As of 2014 the crude death rate for the whole world is 7.89 per 1,000 (down from 8.37 per 1,000 in 2009) according to the current CIA World Factbook. Note that the crude death rate can be misleading. The crude death rate depends on the age (and gender) specific mortality rates and the age (and gender) distribution of the population. The number of deaths per 1,000 people can be higher in developed nations than in less-developed countries, despite a higher life expectancy in developed countries due to better standards of health. This happens because developed countries typically have a much higher proportion of older people, due to both lower birth rates and lower mortality rates. A more complete picture of mortality is given by a life table, which shows the mortality rate separately for each age. A life table is necessary to give a good estimate of life expectancy.
- Perinatal mortality rate – the sum of neonatal deaths and fetal deaths (stillbirths) per 1,000 births.
- Maternal mortality ratio – the number of maternal deaths per 100,000 live births in same time period.
- Maternal mortality rate – the number of maternal deaths per 1,000 women of reproductive age in the population (generally defined as 15–44 years of age).
- Infant mortality rate – the number of deaths of children less than 1 year old per 1,000 live births.
- Child mortality rate: the number of deaths of children less than 5 years old per 1,000 live births.
- Standardized mortality ratio (SMR) – a proportional comparison to the numbers of deaths that would have been expected if the population had been of a standard composition in terms of age, gender, etc.
- Age-specific mortality rate (ASMR) – the total number of deaths per year per 1,000 people of a given age (e.g. age 62 last birthday).
- Cause-specific mortality rate – the mortality rate for a specified cause of death.
- Cumulative death rate: a measure of the (growing) proportion of a group that die over a specified period (often as estimated by techniques that account for missing data by statistical censoring).
- Case fatality rate (CFR) – the proportion of cases of a particular medical condition that lead to death.
- Early mortality rate – the total number of deaths in the early stages of an ongoing treatment, or in the period immediately following an acute treatment.
- Late mortality rate – the total number of deaths in the late stages of an ongoing treatment, or a significant length of time after an acute treatment.
Mortality may also be expressed in terms of survival. Thus, the survival rate is equivalent to "1 minus the cumulative death rate" (with "death from all causes", for example, being expressed in terms of overall survival). Censored survival curves that incorporate missing data by using the Kaplan–Meier estimator can sometimes be compared using statistical tests such as the log-rank test or the Cox proportional hazards test.
The ten countries with the highest crude death rate, according to the 2014 CIA World Factbook estimates, are:
|Rank||Country|| Death rate |
(annual deaths/1,000 persons)
|8||Central African Republic||14.11|
See list of countries by death rate for worldwide statistics.
According to the World Health Organization, the ten leading causes of death in 2002 were:
- 12.6% Ischaemic heart disease
- 9.7% Cerebrovascular disease
- 6.8% Lower respiratory infections
- 4.9% HIV/AIDS
- 4.8% Chronic obstructive pulmonary disease
- 3.2% Diarrhoeal diseases
- 2.7% Tuberculosis
- 2.2% Trachea/bronchus/lung cancers
- 2.2% Malaria
- 2.1% Road traffic accidents
According to Jean Ziegler (the United Nations Special Rapporteur on the Right to Food for 2000 to March 2008), mortality due to malnutrition accounted for 58% of the total mortality in 2006: "In the world, approximately 62 millions people, all causes of death combined, die each year. In 2006, more than 36 million died of hunger or diseases due to deficiencies in micronutrients".
Use in health care
Early recording of mortality rate in European cities proved highly useful in controlling the plague and other major epidemics. Public health in industrialised countries was transformed when mortality rate as a function of age, sex and socioeconomic status emerged in the late 19th and 20th centuries. This track record has led to the argument that inexpensive recording of vital statistics in developing countries may become the most effective means to improve global health. Gathering official mortality statistics can be very difficult in developing countries, where many individuals lack the ability or knowledge to report incidences of death to National Vital Statistics Registries. This can lead to distortion in mortality statistics and a wrongful assessment of overall health. Studies conducted in northeastern Brazil, where underreporting of infant mortality is of huge concern, have shown that alternative methods of data collection, including the use of "popular Death Reporters" (Members of the community who are active in traditional death rituals of the child and the family grieving process), have been very successful in providing valid, qualitative mortality statistics, effectively reducing underreporting.
- Compensation law of mortality
- Gompertz-Makeham law of mortality
- List of causes of death by rate
- List of countries by birth rate
- List of countries by death rate
- Maximum life span
- Mortality displacement
- Risk adjusted mortality rate
- Vital statistics
- Medical statistics
- Weekend effect
- Porta, M, ed. (2014). "Death rate". A Dictionary of Epidemiology (5th ed.). Oxford: Oxford University Press. p. 69. ISBN 978-0-19-939005-2.
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- Everitt, B.S. The Cambridge Dictionary of Statistics, CUP. ISBN 0-521-81099-X
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- Porta, M, ed. (2014). "Case fatality rate". A Dictionary of Epidemiology (5th ed.). Oxford: Oxford University Press. p. 36. ISBN 978-0-19-939005-2.
- Rothman, KJ (2012). Epidemiology: An Introduction. Oxford: Oxford University Press. pp. 49–50. ISBN 978-0-19-975455-7.
- Last, JM, ed. (2008). "Survival rate". A Dictionary of Epidemiology (4th ed.). Oxford: Oxford University Press. p. 240. ISBN 978-0-19-971815-3.
- UNdata: Crude death rate (per 1000 population)
- CIA World Factbook – Death Rate
- Jean Ziegler, L'Empire de la honte, Fayard, 2007 ISBN 978-2-253-12115-2, p.130.
- Aubrey D.N.J, de Grey (2007). "Life Span Extension Research and Public Debate: Societal Considerations" (PDF). Studies in Ethics, Law, and Technology. 1 (1, Article 5). doi:10.2202/1941-6008.1011. Retrieved August 7, 2011.
- Greenwood, Major (2014) . Medical Statistics from Graunt to Farr: The Fitzpatrick Lectures for the Years 1941 and 1943. Cambridge: Cambridge University Press. ISBN 978-1-107-65290-3.
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- Jha, Prabhat (2012). "Counting the dead is one of the world's best investments to reduce premature mortality". Hypothesis. 10 (1). doi:10.5779/hypothesis.v10i1.254.
- "Flesh, Blood, Souls, and Households: Cultural Validity in Mortality Inquiry". Medical Anthropology Quarterly. 5 (3): 204–220. September 1991. doi:10.1525/maq.1991.5.3.02a00020. JSTOR 648673.
- Crude death rate (per 1,000 population) based on World Population Prospects The 2008 Revision, United Nations. Retrieved 22 June 2010
- Rank Order – Death rate in CIA World Factbook
- Mortality in The Medical Dictionary, Medterms. Retrieved 22 June 2010
- "WISQARS Leading Causes of Death Reports, 1999 – 2007", US Centers for Disease Control Retrieved 22 June 2010
- Edmond Halley, An Estimate of the Degrees of the Mortality of Mankind (1693)
|Wikimedia Commons has media related to Birth and death rates.|
- DeathRiskRankings: Calculates risk of dying in the next year using MicroMorts and displays risk rankings for up to 66 causes of death
- Data regarding death rates by age and cause in the United States (from Data360)
- Complex Emergency Database (CE-DAT): Mortality data from conflict-affected populations
- Human Mortality Database: Historic mortality data from developed nations
- Google – public data: Mortality in the U.S.