We search for the determinants of health outcomes, first, by relying on descriptive epidemiology to generate hypotheses about associations between exposures and outcomes. Analytic studies are then undertaken to test specific hypotheses. Samples of subjects are identified and information about exposure status and outcome is collected. The essence of an analytic study is that groups of subjects are compared in order to estimate the magnitude of association between exposures and outcomes.
In their book entitled "Epidemiology Matters" Katherine Keyes and Sandro Galea discuss three fundamental options for studying samples from a population as illustrated in the video below (duration 8:30).
After successfully completing this section, the student will be able to:
- Describe the difference between descriptive and scientific/analytic epidemiologic studies in terms of information/evidence provided for medicine and public health.
- Define and explain the distinguishing features of a cohort study.
- Describe and identify the types of epidemiologic questions that can be addressed by cohort studies.
- Define and distinguish among prospective and retrospective cohort studies using the investigator as the point of reference.
- Define and explain the distinguishing features of a case-control study.
- Explain the distinguishing features of an intervention study.
- Identify the study design when reading an article or abstract.