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Last Edited: 6/2/2001

What is epidemiology?

Epidemiology is the study of the occurrence and causes of health effects in human populations. An epidemiological study often compares two groups of people who are alike except for one factor, such as exposure to a chemical or the presence of a health effect. The investigators try to determine if what factors are associated with the health effect of interest. The major types of epidemiologic studies are analytical studies and descriptive studies.