What is a “blind” or “masked” clinical trial?
You may hear that a treatment is being tested through a “blind” or “masked” clinical trial. This means that participants don’t know whether the treatment they are receiving is the target treatment or a control treatment. If a trial is “double-blind” or “double-masked,” that means that neither the trial participants nor the investigators know who is receiving the target versus control treatments. This is done so that results will not be interpreted based on participants’ or researchers’ expectations or hopes that one treatment will be proven more effective than others. In blind/double-blind or masked/double-masked clinical trials, treatments typically are not revealed except in extreme circumstances.
