A Goneral Procedure for Testing Equivalence

  • Published : 1998.08.01


Motivated by bioequivalence studies which involve comparisons of pharmaceutically equivalent dosage forms, we propose a more general decision rule for showing equivalence simultaneously between multiple means and a control mean. Namely, this testing procedure is concerned with the situation in that one must make decisions as to the bioequivalence of an original drug product and several generic formulations of that drug. This general test is developed by considering a spherical confidence region, which is a direct extension of the usual t-based confidence interval rule formally approved by the U.S. Food and Drug Administration. We characterize the test by the probability of rejection curves and assess its performance via Monte-Carlo simulation. Since the manufacturer's main concern is the proper choice of sample sizes, we provide optimal sample sizes from the Monte-Carlo simulation results. We also consider an application of the generalized equivalence test to a repeated measures design.



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