Jul 28, 2012

Blind and Double Blind—Sound Ominous?

Those terms certainly sound dangerous. But in the world of cancer clinical trials they refer to methods used to make sure experimental drugs are fairly and accurately tested. Blinded studies are also called randomized studies, although not every randomized study is blinded. Just to clear the air about eye safety, the term “blinded” originated when early participants were actually blindfolded—not likely to happen today.

In many clinical trials two or more drugs are compared in the experimental process. In order to make sure all participants are treated equally, they may not be told which of two or more treatments they are receiving—experimental drug (new), standard drug (the best now available), or maybe even a placebo (see previous entries about placebos) if no standard drug exists. This is a “blind” or “blinded” study. If you participate in a blinded study you will not know and will not be able to choose which treatment you receive. This is common in clinical trials.

It is also common for a blinded study to be a “double blinded” study. This is a second step to insure that all participants and all medical procedures are as fair and equal as possible. In a double blind study not only doesn’t the trial participant know what treatment they are receiving, but the doctors, nurses, and other personnel directly administering the trial do not know either. It is possible to be unblinded and know what one is getting - although this is rare. In general, unblinding happens only if there is a severe side effect and the care of the patient requires knowing what drug he or she is receiving.  Unblinding also happens when the clinical trial is over.

While this may seem frustrating for those involved, blinding increases the chances of determining the actual benefit (if there is one) of the experimental treatment being tested in the trial. 

Ominous? Of course not. It’s all just another part of the clinical trial process.

To put a smile on your face see Larry's latest cartoon

(c) 2012 Tom Beer and Larry Axmaker

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