ABSTRACT
Epidemiology can be defined as ‘the scientific study of disease frequency, determinants of disease, and the distribution of disease in a population’. The determinants of disease considered in epidemiological studies are normally demographic parameters (age, sex, occupation, and economic status), in addition to some clinical parameters relevant for the specific disease (e.g., tobacco and alcohol consumption, and reproductive and family history) – all information that can be obtained through registers and questionnaires, whereas parameters requiring special interventions such as blood samples are normally not included in purely epidemiological studies.
