Demography and public health

The health and healthcare needs of a population cannot be measured or met without knowledge of its size and characteristics. Demography is the scientific study of population and is concerned both with the measurement, or estimation, of population size and structure and with population dynamics—the interplay between fertility, mortality, and migration which determines population change. These are pre-requisites for making the forecasts about future population size and structure which largely determine the health profile of a population and should underpin public health planning. This chapter presents information on demographic methods and data sources, their application to health and population issues, information on demographic trends and their implications, and the major theories about demographic change. The aim is to illustrate and elucidate the complex inter-relationship between population change and human health.