Epidemiology is a science of disease occurrence, focusing on disease as stochastic phenomenon. Analyses of large data sets allows an epidemiologist to uncover regularities easily missed in everyday observations.
The traditional definition of epidemiology focuses on causal relations between risk factors and disease occurrence. Historically, epidemiology was concerned mostly with communicable diseases, but modern epidemiology also covers non-communicable diseases, health care interventions. Epidemiology covers both descriptive studies (such as natural disease history and prognosis, surveillance and trends disease incidence) and analytic approaches (e.g. disease etiology and effectiveness of interventions, including randomized trials).
Epidemiologically relevant questions are related to methodology, such as study design, measurement of health and illness as well as their determinants. The classical challenge is distinguishing genuine causal effects from artefactual correlations. The epidemiological concept of causality is based on a probabilistic view: instead of necessary and sufficient causes, epidemiology deals with degrees of probability. Epidemiological research has a wide field of applications from clinical medicine to health policy.
In addition to relations of risk factors with diseases, epidemiology also includes issues relevant for clinical decision-making. Clinical epidemiology covers research questions from evaluation of diagnostic tests and disease prognosis to effectiveness of health services.
At Tampere University, epidemiological research covers cancer etiology and screening, infectious diseases and vaccinations, early nutrition and type 1 diabetes, maternal health and lifestyle, urological disorders and health effects of radiation