Epidemiology

Epidemiology is a discipline or methodology concerned with (a) understanding factors, so called, that influence health and disease states and (b) psychological characteristics/behaviors (such as personality or parenting) and functioning (academic success, income)—together described as outcomes from here on. The ultimate objective of epidemiology is to provide an evidence base to inform which interventions could lead to improved [Page 756]population outcomes. To reach this objective, epidemiologists must carefully draw inferences from complex observations of populations. At the heart of this process are several theoretical and logical underpinnings, methodologies, and statistical approaches, which are described with examples in the following sections.