Double-blind study

What is a “double blind” study?

A double blind study is a research trial where neither you nor the study team know whether you have been assigned to the investigational drug or placebo. We do this so that we can be sure that any differences seen are due to the investigational drug and not some other factor.

Double-Blind study example

Let’s imagine that researchers are investigating the effects of a new drug. In a double-blind study, researchers interacting with participants would not know who was receiving the real drug and who was receiving a placebo. The patients wouldn’t know either because they will be taking a tablet that looks exactly like the one with active medication.

What is the advantage of a double blind study?

A double-blind study reduces the risk of biases in research. Biases can occur when a researcher influences the outcome of a study directly or otherwise. Biases can also be introduced by the patients’ expectations and/or fears.. This allows for credible, reliable, and valid research results.

Unblinding

The process of revealing the group assignment to the researchers and, sometimes, to the study subjects at the end of a trial is called “unblinding.” During the trial, the aim is to avoid any type of clue that would allow experimental subjects or investigators to unmask, in whole or in part, the allocation groups before the conclusion of the trial. The latter is called unintentional unmasking or unblinding.​