Epidemiology

Epidemiology is the study of the distribution and determinants of health-related states or events (such as diseases) in specified populations, and the application of this study to control health problems. It is a major component of public health, and informs policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive health care. It is used to inform governmental public health actions with regard to infectious disease, noninfectious diseases, and environmental hazards, and play a key role in informing effective strategies for health promotion, thus improving the health of populations.