Epidemiology 2: Compared to what? Finding controls for case-control studies

• Published in: The Lancet (British edition) Vol. 365; no. 9468; p. 1429
• Main Authors: Grimes, David A, Schulz, Kenneth F
• Format: Journal Article
• Language: English
• Published: London Elsevier Limited 16.04.2005
• Subjects: Case studies; Clinical trials; Comparative studies; Emergency medical services; Epidemiology; Human subjects; Risk exposure

Use of control (comparison) groups is a powerful research tool. In case-control studies, controls estimate the frequency of an exposure in the population under study. Controls can be taken from known or unknown study populations. A known group consists of a defined population observed over a period,...