Switching between superiority and non-inferiority

Superiority, equivalence, and non-inferiority trials.

When the aim of the randomized controlled trial (RCT) is to show that one treatment is superior to another, a statistical test is employed and the trial (test) is called a superiority trial (test). Often a nonsignificant superiority test is wrongly interpreted as proof of no difference between the two treatments. Proving that two treatments are equal in performance is impossible with statistica...

Methodology of superiority vs. equivalence trials and non-inferiority trials.

The randomized clinical trial (RCT) is generally accepted as the best method of comparing effects of therapies. Most often the aim of an RCT is to show that a new therapy is superior to an established therapy or placebo, i.e. they are planned and performed as superiority trials. Sometimes the aim of an RCT is just to show that a new therapy is not superior but equivalent to or not inferior to a...

Editorial on hypothesis and objectives in clinical trials: superiority, equivalence and non-inferiority

Editorial Randomized clinical trial is often considered as the Gold Standard method for comparing treatment effects. In practice, taking into consideration their main objectives, the majority of clinical trials are aimed to establish the superiority of an intervention regarding to an active control or placebo [1]. Within the methodological core of these so called superiority trials, the assessm...

Statistical Considerations for Randomized Controlled Trials [RCTs] - Understanding Superiority, Equivalence and Non-inferiority Designs.

Optimal group-sequential designs for simultaneous testing of superiority and non-inferiority.

Confirmatory clinical trials comparing the efficacy of a new treatment with an active control typically aim at demonstrating either superiority or non-inferiority. In the latter case, the objective is to show that the experimental treatment is not worse than the active control by more than a pre-specified non-inferiority margin. We consider two classes of group-sequential designs that combine t...