thumb|400px|Mortality rate of countries, deaths per thousand

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", which is 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). As of 2024, the global crude death rate stood at 7.76, marking a 2.35% rise compared to 2023. In a generic form,

Crude death rate, per 100,000 population

  1. Ischaemic heart disease, 126
  2. Stroke, 77
  3. Chronic obstructive pulmonary disease, 41
  4. Lower respiratory infections, 40
  5. Alzheimer's disease and other dementias, 27
  6. Trachea, bronchus, and lung cancers, 23
  7. Diabetes mellitus, 21
  8. Road injury, 19
  9. Diarrhoeal diseases, 19
  10. Tuberculosis, 17

Mortality rate is also measured per thousand. It is determined by how many people of a certain age die per thousand people. Decrease of mortality rate is one of the reasons for increase of population. Development of medical science and other technologies has resulted in the decrease of mortality rate in all the countries of the world for some decades. In 1990, the mortality rate of children under five years of age was 144 per thousand, but in 2015 the child mortality rate was 38 per thousand.

Other specific measures of mortality include:

{| class="wikitable sortable"

|+Measures of mortality

!width=250pt|Name!!Typical definition

|-

|Perinatal mortality rate||The sum of fetal deaths (stillbirths) past 22 (or 28) completed weeks of pregnancy plus the number of deaths among live-born children up to 7 completed days of life, divided by number of births.

|-

|Maternal mortality rate||Number of deaths of mothers assigned to pregnancy-related causes during a given time interval, divided by the number of live births during the same time interval.

|-

|Standardized mortality ratio (SMR)||The ratio of the number of deaths in a given (index) population to the number of deaths expected, a form of indirectly (as opposed to directly) standardized rates, where the categories are usually "defined by age, gender and race or ethnicity". The numerator is calculated as <small><math>\sum n_iR_i</math></small>, where "<small><math>n_i</math></small> is the number of persons in category <small><math>i</math></small> of the index population and <small><math>R_i</math></small> is the corresponding category-specific event rate in a standard population."

|-

|Age-specific mortality rate (ASMR)||The total number of deaths per year at a specific age, divided by the number of living persons at that age (e.g. age 62 at last birthday)

|-

|Infection fatality rate (IFR)||The proportion of infected cases of a particular medical condition that lead to death. Similar to CFR, but adjusted for asymptomatic and undiagnosed cases.

|}

For any of these, a "sex-specific mortality rate" refers to "a mortality rate among either males or females", where the calculation involves both "numerator and denominator... limited to the one sex".

Census data and vital statistics

Ideally, all mortality estimation would be done using vital statistics and census data. Census data will give detailed information about the population at risk of death. The vital statistics provide information about live births and deaths in the population. Often, either census data and vital statistics data is not available. This is common in developing countries, countries that are in conflict, areas where natural disasters have caused mass displacement, and other areas where there is a humanitarian crisis

Orphanhood surveys estimate mortality by questioning children are asked about the mortality of their parents. It has often been criticized as an adult mortality rate that is biased for several reasons. The adoption effect is one such instance in which orphans often do not realize that they are adopted. Additionally, interviewers may not realize that an adoptive or foster parent is not the child's biological parent. There is also the issue of parents being reported on by multiple children while some adults have no children, thus are not counted in mortality estimates.

Mortality statistics

Causes of death vary greatly between developed and less developed countries; see also list of causes of death by rate for worldwide statistics.

{|class="wikitable" style="float:right; margin: 0.5em 0 0.5em 1em; text-align:left"

|+ World historical and predicted crude death rates (1950–2050) <br /><small>UN, medium variant, 2012 rev.</small>

|-

!Years!!CDR!!Years!!CDR

|-

|1950–1955|| align="center" |19.1||2000–2005|| align="center" |8.4

|-

||1955–1960|| align="center" |17.3||2005–2010|| align="center" |8.1

|-

||1960–1965|| align="center" |16.2||2010–2015|| align="center" |8.1

|-

||1965–1970|| align="center" |12.9||2015–2020|| align="center" |8.1

|-

||1970–1975|| align="center" |11.6||2020–2025|| align="center" |8.1

|-

||1975–1980|| align="center" |10.6||2025–2030|| align="center" |8.3

|-

||1980–1985|| align="center" |10.0||2030–2035|| align="center" |8.6

|-

||1985–1990|| align="center" |9.4||2035–2040|| align="center" |9.0

|-

||1990–1995|| align="center" |9.1||2040–2045|| align="center" |9.4

|-

||1995–2000|| align="center" |8.8||2045–2050|| align="center" |9.7

|}

thumb|right|upright=1.35|Scatter plot of the [[natural logarithm (ln) of the crude death rate against the natural log of per capita GDP. The slope of the trend line is the elasticity of the crude death rate with respect to per capita income. It indicates that as of the date of the basis data set, an increase in per capita income tends to be associated with a decrease in the crude death rate. Source: World Development Indicators.]]

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 million 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".

Of the roughly 150,000 people who die each day across the globe, about two thirds—100,000 per day—die of age-related causes. In industrialized nations, the proportion is much higher, reaching 90%. Indian economist and philosopher Amartya Sen has stated that mortality rates can serve as an indicator of economic success and failure.

Historically, mortality rates have been adversely affected by short term price increases. Studies have shown that mortality rates increase at a rate concurrent with increases in food prices. These effects have a greater impact on vulnerable, lower-income populations than they do on populations with a higher standard of living.

Preventable mortality

These rates are especially pronounced for children under 5 years old, particularly in lower-income, developing countries. These children have a much greater chance of dying of diseases that have become mostly preventable in higher-income parts of the world. More children die of malaria, respiratory infections, diarrhea, perinatal conditions, and measles in developing nations. Data shows that after the age of 5 these preventable causes level out between high and low-income countries.

See also

  • Biodemography
  • Compensation law of mortality
  • Demography
  • Gompertz–Makeham law of mortality
  • Life table
  • List of causes of death by rate
  • List of countries by birth rate
  • List of countries by death rate
  • List of countries by life expectancy
  • Maximum life span
  • Medical statistics
  • Micromort
  • Mortality displacement
  • Risk adjusted mortality rate
  • Vital statistics
  • Weekend effect
  • World population

References

Sources

  • 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)
  • 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
  • Deaths this year
  • OUR WORLD IN DATA: Number of deaths per year, World