What is a cohort design?

An observational design where patients are selected on the basis of an exposure variable. Contrast this with a case control design. Here is an example:

• In Beral et al (1999), general practitioners in the United Kingdom recruited 23,000 women who were using oral contraceptives and a similar number of women who were not using oral contraceptives. The researchers followed both groups of women for 25 years and noted how many died.

This webpage was written by Steve Simon on 2002-10-11, edited by Steve Simon, and was last modified on 2008-07-08. This page needs minor revisions. Category: Definitions, Category: Research designs.