Definition von Epidemiologie

The study of the occurrence and distribution of health-related events, states, and processes in specified populations, including the study of the determinants influencing such processes, and the application of this knowledge to control relevant health problems.

The primary "knowledge object" of epidemiology as a scientific discipline are causes of health-related events, states, and processes in groups and populations. In the past 90 years, the definition has broadened from concern with communicable disease epidemics to include all phenomena related  to health in populations.

Therefore, epidemiology is much more than a branch of medicine treating of epidemics. Epidemiology may also study disease in populations of animals and plants.

International Epidemiological Association. A Dictionary of Epidemiology (ed. Porta M). Oxford: Oxford University Press, 6th edition, 2014

Study includes surveillance, observation, screening, hypothesis testing, analytic research, experiments, and prediction.

Distribution refers to analysis by time, place (or space), and population.

Determinants are the geophysical, biological, behavioural, social, cultural, economic, and political factors that influence health.

Health-related events, states, and processes include outbreaks, diseases, disorders, causes of death, behaviours, environmental and socioeconomic processes, effects of preventive programmes, and use of health  and social services.

Specified populations are those with common contexts and identifiable characteristics.

Application to control ... makes explicit the aim of epidemiology: to promote, protect, and restore health, and to advance scientific knowledge.