ABSTRACT
One of the foundation stones of public health is epidemiology. The science of epidemiology is concerned with the states of health and disease in natural populations. Epidemiology is the study of the distribution and determinants of disease in human populations. In public health, planned epidemiological studies are used to address specific questions about health and disease in populations and the factors that influence them. The main source of demographic data within the United Kingdom is the census. The original rationale for the census was the notion that the knowledge of a country must inform the basis of legislation and diplomacy. In the United Kingdom, it is compulsory to register births and deaths. These registrations are an important routine data source for planning, policymaking and describing the health of the population. While mortality data are vital for public health use, they give an incomplete picture of disease within the population.
