Saturday, 12 July 2014 10:57



Demography is the study of the growth, change, and structure of the human population. Changes in a population's size and structure are caused by changes in the birthrate, the death rate, and the net migration rates. Demographic research focuses on why people have the number of children they do; on factors that affect death rates; and on the reasons for immigration, emigration, and geographic mobility. Understanding a society's demography is an essential tool in determining current and future public health needs.


The infant mortality rate (IMR) is the ratio of the number of deaths among children less than one year old during a given year to the number of live births during the same year. An infant must adapt to a rapidly changing environment, and death may occur if this adaptation is not successful. Traditionally, this has been expressed by stating that the most dangerous times in the life of a human being are "the first day, the first week, the first month, the first year," in that order. In many regions of the world, the risk of dying within the first year of life will only be matched at the ages of eighty and beyond.

The death of an infant is often dependent on external factors, especially in developing countries. Poor water quality, an inadequate food supply, substandard health services, and a high level of infectious diseases such as malaria all contribute to a high


The death-rate, usually standardized by age and sex, to facilitate comparisons between areas and social groups. It provides a measure of health risks, improvements in the quality of health care, and the comparative overall health of different groups in the population. It is thus used as a reliable indicator of social and economic change, and of comparative standards of living, as well as by epidemiologists who are interested in monitoring the risk of death from infectious diseases and other causes. A variety of mortality rates are used, each with its own purpose, with the overall national death-rate used as the starting-point for comparisons between areas and social groups in a society.