Epidemiology - Basic Epidemiology
1. What is Epidemiology?
Epidemiology has been defined as the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to control of health problems. (Last, 1995). Epidemiology has a range of common uses in public health including attribution of causation, description of the natural history of disease, description of the health status of populations and evaluation of interventions.
Causation of disease can be linked to either genetic factors or a combination of genetic factors and environmental factors. This is illustrated in figure 1 below.
Figure 1 Causation
The course and outcome of diseases can be described as the natural history of the disease and, in this context, epidemiology can play an important part in preventative and clinical medicine. This is illustrated in figure 2 below.
Figure 2 Natural History