Good studies are "controlled." In a controlled study some participants are given the treatment and others—the "control" group—are given either a placebo or another treatment, or, less optimally, left untreated altogether.
"Uncontrolled" studies, in which everyone is given the treatment, are highly unreliable for many reasons. One problem is that it is impossible to know how well participants would have done without any treatment at all. Additionally, individuals who know they are being treated may naturally begin to pay more attention to their disease and take better care of themselves.
Last reviewed April 2009 by
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.