Epidemiology is the science of identifying and understanding the patterns, determinants or causes and effects of disease in human populations. The Greek term literally means “the study of what is upon the people” and it represents the major means of reporting and tracking disease in public health, informs policy decisions and evidence-based practice.
The methods used in epidemiology include; study design, population identification or study cohort ascertainment, and statistical analysis of the data. Epidemiological investigations identify the determinants or causes of disease, patterns of disease, surveillance and monitoring of disease, and comparisons of treatment effects, as examples. Some specific areas of epidemiologic research include: genetic epidemiology, environmental epidemiology and social epidemiology.
Epidemiology is a major component of public health and global medicine defined as population-based studies of health and disease, particularly relating to patterns, cause, and effect. The research in this area is focused on contributions to control and prevention of disease and health problems, and includes studies of outbreak investigation, disease screening, and disease origin. This field relies heavily on statistical analysis to explain and validate the association of a variable of interest with a particular disease.