ABSTRACT
Epidemiology is the study of the distribution of disease or physiological condition in human populations and of the factors affecting their distribution. It is important to understand that epidemiology is concerned with the study of populations not the individual. The prime objective of epidemiology is to judge whether an association between exposure and disease is in fact causal. Descriptive epidemiology is concerned with the distribution of disease, including consideration of which populations or subgroups do or do not develop a disease, in what geographic location a disease is most or least common, and how the frequency of occurrence varies over time. Health professionals can allocate resources efficiently, plan effective prevention and education programmes with the use of descriptive epidemiology. Analytical epidemiology focuses on the determinants of disease, with the ultimate goal of judging whether a particular exposure causes or prevents a specific disease.
