Scope of epidemiological enquiry and overview of main problem areas

Epidemiology can be considered as a suite of methodologies designed to inform on aspects of health and disease in human populations. They have been designed to cope with the variability between people in the risk for diseases and their course and response to treatments. There are many aspects of epidemiological study that are challenging and the successful study requires attention to the design, conduct of the study, and analysis of the data generated. There is another view of epidemiology, which is that it is a tool for studying diseases as they occur in human populations. The focus can also be on diagnosis, outcome, and results of interventions, as well as on causes. This broader definition allows a greater scope for the kinds of question that can be addressed both by those studying the health of populations and by those whose main focus is the study of disease in patient groups.