Understanding equivalence and noninferiority testing

Abstract

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.

Figure 1

Two one-sided test procedure (TOST) and the equivalence margin in equivalence/noninferiority testing.

Figure 2

Results of traditional two-sided and two one-sided test (TOST) (δ = 5) procedures to compare MMR vaccination coverages between white and minority group children (adapted from Barker,7).