Open Label Trials definition
An open label trial is a research study involving medication, the identity of which is known to the patient.
Open label clinical trials
In most well-designed clinical studies, the patient does not know which of two (or more) alternative treatments he or she is receiving. The purpose of this secrecy is to keep patient biases from inadvertently affecting the results.
For example: subjects who think that they are receiving a promising experimental drug may receive some psychological benefit from this knowledge and actually appear to improve -- even if the drug itself is not effective (see also Placebo Effect).
Except in very rare cases, a well-designed study will avoid open-label trials and instead keep the patients "blind" with respect to which treatment they are receiving.
The most preferred design is a double-blind procedure in which neither the patients nor the researchers know which patients have been assigned to which treatments, thus avoiding any inadvertent biases on the part of either patients or researchers.
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain.