Quality of Reporting of Noninferiority and Equivalence Randomized Trials

Abstract

A noninferiority or equivalence trial aims to demonstrate that the experimental treatment is not clinically worse than the comparator (an active control treatment) by more than a prespecified small amount (Δ), known as the noninferiority or equivalence margin.¹ According to the International Conference on Harmonization guidelines,² the term noninferiority is used when referring to a 1-sided trial (difference in response lower than Δ); equivalence, when referring to 2-sided trials (difference in response between −Δ and +Δ). The new treatment is expected to have noninferior or equivalent efficacy compared with the standard treatment but could have advantages in safety, convenience (eg, administration once a day instead of 3 times a day), or cost. The new treatment may also present an alternative or second-line therapy.³