Journal of General Internal Medicine

, Volume 26, Issue 2, pp 192–196 | Cite as

Understanding Equivalence and Noninferiority Testing

  • Esteban Walker
  • Amy S. Nowacki


Increasingly, the goal of many studies is to determine if new therapies have equivalent or noninferior efficacies to the ones currently in use. These studies are called equivalence/noninferiority studies, and the statistical methods for their analysis require only simple modifications to the traditional hypotheses testing framework. Nevertheless, important and subtle issues arise with the application of such methods. This article describes the concepts and statistical methods involved in testing equivalence/noninferiority. The aim is to enable the clinician to understand and critically assess the growing number of articles utilizing such methods.


equivalence margin TOST hypotheses testing 


Conflict of Interest

None disclosed.


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Copyright information

© Society of General Internal Medicine 2010

Authors and Affiliations

  1. 1.Department of Quantitative Health SciencesCleveland ClinicClevelandUSA

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