Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
Mortality rate is a measure of the number of deaths (in general, or due to a specific cause) in some population, scaled to the size of that population, per unit time. Mortality rate is typically expressed in units of deaths per 1000 individuals per year; thus, a mortality rate of 9.5 in a population of 100,000 would mean 950 deaths per year in that entire population. It is distinct from morbidity rate, which refers to the number of individuals who have contracted a disease during a given time period (the incidence rate) or the number who currently have that disease (the prevalence rate), scaled to the size of the population.
- The crude death rate, the total number of deaths per 1000 people.
- The perinatal mortality rate, the sum of neonatal deaths and fetal deaths (stillbirths) per 1,000 births.
- The maternal mortality rate, the number of maternal deaths due to childbearing per 100,000 live births.
- The infant mortality rate, the number of deaths of children less than 1 year old per thousand live births.
- The child mortality rate, the number of deaths of children less than 5 year old per thousand live births.
- The standardised mortality rate (SMR) or age-specific mortality rate (ASMR) - This refers to the total number of deaths per 1000 people of a given age (e.g. 16-65 or 65+).
In regard to the success or failure of medical treatment or procedures, one would also distinguish:
- 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.
- 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 of people can give a misleading impression. For example, the number of deaths per 1000 people can be higher for developed nations than in less-developed countries, despite standards of health being better in developed countries. This is because developed countries have relatively more older people, who are more likely to die in a given year, so that the overall mortality rate can be higher even if the mortality rate at any given age is lower. A more complete picture of mortality is given by a life table which summarises mortality separately at each age. A life table is necessary to give a good estimate of life expectancy.
The ten countries with the highest infant mortality rate are:
- Angola 192.50
- Afghanistan 165.96
- Sierra Leone 145.24
- Mozambique 137.08
- Liberia 130.51
- Niger 122.66
- Somalia 118.52
- Mali 117.99
- Tajikistan 112.10
- Guinea-Bissau 108.72
According to the World Health Organisation, the 10 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% Malaria
- 2.2% Trachea/bronchus/lung cancers
- 2.1% Road traffic accidents
Causes of death vary greatly between developed and developing countries. See List of causes of death by rate for worldwide statistics.
Factors affecting a country's death rate
- Age of country's population
- Nutrition levels
- Standards of diet and housing
- Access to clean drinking water
- Hygiene levels
- Levels of infectious diseases
- Levels of violent crime
- Number of doctors
Sources and references
- CIA World Factbook -- Rank Order - Death rate
- Mortality - The Medical Dictionary by Medterms
- "10 Leading Causes of Death, United States" from the Center for Disease Control
- Edmond Halley, An Estimate of the Degrees of the Mortality of Mankind (1693).
- Birth rate
- Compensation law of mortality
- Gompertz-Makeham law of mortality
- Iatrogenesis - more than 200 000 deaths yearly in USA
- Life expectancy
- List of causes of death by rate
- List of countries by death rate
- Maximum life span
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