What is epidemiology?
epidemiology is The study of the various factors influencing the occurrence, distribution, prevention and control of disease, injury and other health-related events in a defined population. Epidemiology utilizes biology, clinical medicine, and statistics in an effort to understand the etiology (causes) and course of illness and/or disease. The ultimate goal of the epidemiologist is, not merely to identify underlying causes of a disease, but to apply findings to disease prevention and health promotion.
source: A GLOSSARY OF TERMS FOR COMMUNITY HEALTH CARE AND SERVICES FOR OLDER PERSONS. World Health Organization, 2004.