Mortality rate

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Crude death rate by country (2006).

Mortality rate is a measure of the number of deaths (in general, or due to a specific cause) in a 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 rate, which refers to the number of individuals in poor health during a given time period (the prevalence rate) or the number of newly appearing cases of the disease per unit of time (incidence rate). The term "mortality" is also sometimes inappropriately used to refer to the number of deaths among a set of diagnosed hospital cases for a disease or injury, rather than for the general population of a country or ethnic group. This disease mortality statistic is more precisely referred to as "case fatality rate" (CFR).

One distinguishes:

  1. The crude death rate, the total number of deaths per year per 1,000 people. As of July 2009 the crude death rate for the whole world is about 8.37 per 1,000 per year according to the current CIA World Factbook.[1]
  2. The perinatal mortality rate, the sum of neonatal deaths and fetal deaths (stillbirths) per 1,000 births.
  3. The maternal mortality ratio, the number of maternal deaths per 100,000 live births in same time period.
  4. The 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) .
  5. The infant mortality rate, the number of deaths of children less than 1 year old per 1,000 live births.
  6. The child mortality rate, the number of deaths of children less than 5 years old per 1,000 live births.
  7. The standardised mortality ratio (SMR)- This represents 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.[2]
  8. The age-specific mortality rate (ASMR) - This refers to the total number of deaths per year per 1,000 people of a given age (e.g. age 62 last birthday).

In regard to the success or failure of medical treatment or procedures, one would also distinguish:

  1. The 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.
  2. The 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.

Note that the crude death rate as defined above and applied to a whole population can give a misleading impression. 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 for developed nations than in less-developed countries, despite life expectancy being higher in developed countries due to standards of health being better. This happens because developed countries typically have a completely different population age distribution, with a much higher proportion of older people, due to both lower recent 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.

Statistics[edit]

World historical and predicted crude death rates (1950–2050)
UN, medium variant, 2008 rev.[3]
Years CDR Years CDR
1950–1955 19.5 2000–2005 8.6
1955–1960 17.3 2005–2010 8.5
1960–1965 15.5 2010–2015 8.3
1965–1970 13.2 2015–2020 8.3
1970–1975 11.4 2020–2025 8.3
1975–1980 10.7 2025–2030 8.5
1980–1985 10.3 2030–2035 8.8
1985–1990 9.7 2035–2040 9.2
1990–1995 9.4 2040–2045 9.6
1995–2000 8.9 2045–2050 10

The ten countries with the highest crude death rate, according to the 2012 CIA World Factbook estimates, are:[4]

Rank Country Death rate
(annual deaths/1,000 persons)
1  South Africa 17.23
2  Ukraine 15.76
3  Lesotho 15.18
4  Chad 15.16
5  Guinea-Bissau 15.01
6  Central African Republic 14.71
7  Afghanistan 14.59
8  Somalia 14.55
9  Bulgaria 14.32
10  Swaziland 14.21

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:

  1. 12.6% Ischaemic heart disease
  2. 9.7% Cerebrovascular disease
  3. 6.8% Lower respiratory infections
  4. 4.9% HIV/AIDS
  5. 4.8% Chronic obstructive pulmonary disease
  6. 3.2% Diarrhoeal diseases
  7. 2.7% Tuberculosis
  8. 2.2% Trachea/bronchus/lung cancers
  9. 2.2% Malaria
  10. 2.1% Road traffic accidents

Causes of death vary greatly between first and third world countries. See list of causes of death by rate for worldwide statistics.

Scatter plot of the natural logarithm of the crude death rate against the natural log of per capita real GDP. The slope of the trend line is the elasticity of the crude death rate with respect to per capita real income. It indicates that a 10% increase in per capita real income is associated with a 1.5% 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 millions people, all causes of death combined, die each year. In 2006, more than 36 millions died of hunger or diseases due to deficiencies in micronutrients".[5]

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.[6] In industrialized nations, the proportion is much higher, reaching 90%.[6]

Use in Health Care[edit]

Early recording of mortality rate in European cities proved highly useful in controlling the plague and other major epidemics.[7] Public health in industrialized countries was transformed when mortality rate as a function of age, sex and socioeconomic status emerged in the late 19th and 20th centuries.[8][9] 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.[10] 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.[11]

See also[edit]

References[edit]

  1. ^ CIA World Factbook -- Rank Order - Death rate Search for "World".
  2. ^ Everitt, B.S. The Cambridge Dictionary of Statistics, CUP. ISBN 0-521-81099-X
  3. ^ UNdata: Crude death rate (per 1,000 population)
  4. ^ CIA World Factbook - Death Rate
  5. ^ Jean Ziegler, L'Empire de la honte, Fayard, 2007 ISBN 978-2-253-12115-2, p.130.
  6. ^ a b 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. 
  7. ^ Greenwood M. Medical Statistics from Graunt to Farr. The Fitzpatrick Lectures for the Years 1941 to1943. Cambridge: Cambridge University Press; 1948.
  8. ^ Jha P. Avoidable mortality in India: past progress and future prospects. Natl Med J India. 2002;15 Suppl 1:32-6.
  9. ^ Jha P. Reliable mortality data: a powerful tool for public health. Natl Med J India. 2001;14:129-31. PMid:11467137
  10. ^ 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. 
  11. ^ http://www.jstor.org.proxy.lib.sfu.ca/stable/pdfplus/648673.pdf?acceptTC=true

Other Sources[edit]

External links[edit]