||These four stages
of information development take us from recognition of a health problem
through its solution. Evoking the philosophy and work of the Centers for
Disease Control and Prevention (CDC), they constitute the Public Health
Approach to problem solving. The first two stages fall under the realm of
descriptive epidemiology. Stages three and four involve analytic
epidemiology, with its capacity to evaluate both putative cause-and-effect
relationships and interventions based on this etiologic understanding.
Etiology is the science of causation.