Comparisons of Superiority, Non-inferiority, and Equivalence Trials.

Abstract

Efficacy of a new drug or treatment is usually established through randomized clinical trials. However, specifying hypotheses remains a challenging problem for biomedical researchers. In this survey we discuss superiority, non-inferiority, and equivalence trials. These three types of trials have different assumptions on treatment effects. We compare the assumptions underlying these trials and provide sample size formulas.