Epidemiology is the population study of health and development and of the underlying risk and protective factors. The purpose of collecting the data is to understand the causes of impairments to health and development and to provide the logic for population-wide and targeted prevention strategies. Epidemiology generally involves collecting data on all children and/or families in a specified geographical area, such as a community or local government area. The approach has been responsible for major breakthroughs in preventative medicine, for example in identifying the association between smoking and cancer.
