Child mortality is typically defined as the number of deaths of children under five years of age in a given year per one thousand children in this age group. The age parameters, however, may vary among different reports. Some reports might include only children between the ages of one and four years, while others might include all minor children. It is imperative to note the operational definition employed in a report before making comparisons with other reported data.
The utility of child mortality as a health indicator depends upon the population context in which it is used. For example, in a developed country, where the leading global causes of child mortality are not as prevalent, the rates of specific causes of child mortality could be used in the prioritization of prevention programming (e.g., geared toward motor vehicle passenger safety). In a developing country, however, child mortality rates may play a more significant role as an indicator of broader health, and of environmental and social issues, such as malnutrition, water sanitation, poverty, and access to health systems.
From a statistical perspective, it is important to note that child mortality may drastically skew life expectancy measures. For example, the reported life expectancy at birth for a population with a high child mortality rate may be significantly shorter than a population with a low child mortality rate—even though the life expectancy at five years of age might be similar between the two populations.
THOMAS C. QUADE
Last, John M., ed. (1995). A Dictionary of Epidemiology, 3rd edition. New York: Oxford University Press.