Definition: A control group is a comparison group. To understand how effective a new medication may be, researchers need to compare it to something, often a placebo or an existing medication. The people in the control group will not be given the new medication. Generally no one knows which group they are in until the trial is finished.
Control Group for Clincal Trials
By Julie Stachowiak, Ph.D., About.com
Updated: April 30, 2007
About.com Health's Disease and Condition content is reviewed by the Medical Review Board
More on MS Symptoms
MS Symtpom OverviewBladder Dysfunction and MSKeep a Symptom Log
MS Basics
Explore Multiple Sclerosis
Must Reads
About.com Special Features
Learn how you can reduce your your numbers with these nutrition and exercise tips. More >
Keep yourself, and your family, happy and healthy this fall with these tips. More >
Also from About.com:
©2009 About.com, a part of The New York Times Company.
All rights reserved.