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 printable version
Age-standardized mortality rates by cause (per 100 000 population)
Rationale for use
The numbers of deaths per 100 000 population are influenced by the age distribution of the population. Two populations with the same age-specific mortality rates for a particular cause of death will have different overall death rates if the age distributions of their populations are different. Age-standardized mortality rates adjust for differences in the age distribution of the population by applying the observed age-specific mortality rates for each population to a standard population.
Definition
The age-standardized mortality rate is a weighted average of the age-specific mortality rates per 100 000 persons, where the weights are the proportions of persons in the corresponding age groups of the WHO standard population.
The WHO World Standard Population was based on the average world population structure for the period 2000-2025 as assessed every two years by the United Nations Population Division (UNPD) for each country by age and sex. Estimates from the UNDP 1998 assessment (being the latest one at the time the WHO Standard Population was chosen) based on population censuses and other demographic sources, adjusted for enumeration errors were used. The use of an average world population as well as a time series of observations removes the effects of historical events such as wars and famine on population age composition. WHO Standard Population is defined to reflect the average age structure of the world's population over the next generation, from the year 2000 to 2025.
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Age standardization of rates: a new WHO standard [pdf 50kb]
From Ahmad O, Boschi-Pinto C, Lopez AD, Murray CJL, Lozano R, Inoue M. Age standardization of rates: a new WHO standard. Geneva, World Health Organization, 2001
Associated terms
None.
Data sources
Death registration data for 112 WHO Member States, sample registration systems (India, China), available data on child and adult mortality from censuses and surveys, together with population-based epidemiological studies, disease registers and notifications systems for the estimation of mortality for 21 specific causes of death.
Methods of estimation
Life tables specifying all-cause mortality rates by age and sex for 192 WHO Member States were developed for 2002 from available death registration data, sample registration systems (India, China) and data on child and adult mortality from censuses and surveys.
Cause-of-death distributions were estimated from death registration data for 107 countries, and data from population-based epidemiological studies, disease registers and notifications systems for selected specific causes of death. Causes of death for populations without useable death-registration data were estimated using cause-of-death models together with data from population-based epidemiological studies, disease registers and notifications systems for 21 specific causes of death.
Disaggregation
By age and sex.
References
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Discussion Paper 31: Age Standardization of Rates: A New WHO Standard [pdf 50kb]
Ahmad O, Boschi-Pinto C, Lopez AD, Murray CJL, Lozano R, Inoue M. Age standardization of rates: a new WHO standard. Geneva, World Health Organization, 2001 (GPE Discussion Paper No. 31).
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Global burden of disease and risk factors
Lopez AD, Mathers CD, Ezzati M, Murray CJL, Jamison DT. Global burden of disease and risk factors.New York, Oxford University Press, 2006.
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Uncertainty and data availability for the global burden of disease estimates 2000–2002
Mathers CD. Uncertainty and data availability for the global burden of disease estimates 2000–2002. Geneva, World Health Organization, 2005 (Evidence and Information for Policy Working Paper).
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Counting the dead and what they died from: an assessment of the global status of cause of death data
Mathers CD, Ma Fat D, Inoue M, Rao C, Lopez AD. Counting the dead and what they died from: an assessment of the global status of cause of death data. Bulletin of the World Health Organization, 2005, 83:171–177.
Database
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WHO Mortality Database: Tables
WHO Mortality Database. The data available on this web site comprise deaths registered in national vital registration systems, with underlying cause of death as coded by the relevant national authority.
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Estimates of death rates for 2002 by cause for WHO Member States [xls 3.03Mb]
Estimates of death rates for 2002 by cause for WHO Member States. The Excel spreadsheet contains estimates of numbers, crude rates and age-standardized rates, as well as information on data sources and levels of evidence
Comments
Uncertainty in estimated all-cause mortality rates ranges from around ±1% for high-income countries to ±15–20% for sub-Saharan Africa, reflecting large differences in the availability and quality of data on mortality, particularly for adult mortality. Uncertainty ranges are generally larger for estimates of death rates from specific diseases. For example, the relative uncertainty for death rates from ischaemic heart disease ranges from around ±12% for high-income countries to ±25–35% for sub-Saharan Africa. The relatively large uncertainty for high-income countries reflects a combination of uncertainty in overall mortality levels, in cause-of-death assignment, and in the attribution of deaths coded to ill-defined causes.
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