Mortality Rates, Global

There are major differences today in the mortality rates of the countries of the world. Babies born in Japan or Sweden live much longer than those born in Botswana or in Lesotho Southern Africa. Why do these differences in life expectancy exist among countries? Levels of development, medical conditions, and a host of other factors are involved.

The major causes of death are not the same in countries with high and low levels of life expectancy. There have been changes over time in the major causes of death. People used to die mainly of infectious and parasitic diseases, but the major causes of death today in developed countries such as the United States are heart disease and cancer. In this entry, we discuss these and related issues.

Historical Evidence

Our knowledge of mortality levels and conditions prior to the Industrial Revolution is incomplete. We know that mortality was high then, but the availability and completeness of the death data leave a lot to be desired. According to Scheidel, age data from census records of Roman Egypt indicate an average life expectancy at birth in the 1st to 3rd centuries C.E. of between 22 and 25 years, a finding corroborated by data on tombstones in Roman North Africa. As late as the 18th century, life expectancy ranged from only 30 to 40 years in much of Europe and the United States. Males in the United States in 1901 had a life expectation at birth of 47.9 years, and females, 50.7 years.

Causes of Death

The eminent demographer Donald Bogue has noted that death is caused by a number of reasons and diseases, which require the understanding of the etiological factors of the major causes of death. Data on the causes of death, even today, are far from complete. Some deaths around the world are not even registered. In many countries, a large proportion of deaths occur outside the presence of a physician, and the cause is either unknown or incorrectly diagnosed. Often the cause of death is misrepresented or camouflaged if it is socially unacceptable, such as suicide, syphilis, or HIV/AIDS.

Moreover, international comparisons of causeof-death data are difficult because countries often differ in terminology, method of certification, diagnostic techniques, and the quality of the coding and data collection system. Nevertheless, some generalizations are possible about the general structure of cause of death in the contemporary world.

Death is a complex behavior, and there are literally many thousands of ways to die. But some causes of death occur more frequently than others. For instance, the World Health Organization reports that in 2002 there were approximately 57 million deaths in the world. The top cause of death throughout the world was cardiovascular disease; coronary heart disease accounted for 7.2 million deaths, and cerebrovascular disease and stroke accounted for another 5.5 million deaths.

People around the world, however, do not all die of the same major causes. There are differences, and these are largely due to the socioeconomic levels of the countries. The World Health Organization has developed an illustrative example. Consider a hypothetical population of 1,000 people to represent all the women, men, and children around the world who died in 2002. Of these 1,000 decedents, 138 of them will have come from rich countries, 362 from middle-income countries, and 501 from poor countries. For each group of countries, the distributions of deaths are not identical, nor are they ranked in the same way.

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