ABSTRACT
INTRODUCTION Epidemiology is the study of health in relation to populations. Succinctly, it has been described as the basic quantitative science of public health. It differs from clinical medicine in that the results of epidemiological research have relevance to public health with consequences for health at the level of the population rather than the individual. It has been described as the study of the distribution and determinants of health-related states or events in specified populations and the application of this to the control of health problems.
