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Randomization Strategies

Kepler, Christopher K. MD, MBA

doi: 10.1097/BSD.0000000000000523

An understanding of randomization is important both for study design and to assist medical professionals in evaluating the medical literature. Simple randomization can be done through a variety of techniques, but carries a risk of unequal distribution of subjects into treatment groups. Block randomization can be used to overcome this limitation by ensuring that small subgroups are distributed evenly between treatment groups. Finally, techniques can be used to evenly distribute subjects between treatment groups while accounting for confounding variables, so as to not skew results when there is a high index of suspicion that a particular variable will influence outcome.

Thomas Jefferson University & Rothman Institute, Philadelphia, PA

The author declares no conflict of interest.

Reprints: Christopher K. Kepler, MD, MBA, Thomas Jefferson University & Rothman Institute, 925 Chesnut Street, 5th Floor, Philadelphia, PA 19103 (e-mail:

Received January 27, 2017

Accepted January 31, 2017

© 2017 by Lippincott Williams & Wilkins, Inc.