Non-inferiority statistics and equivalence studies

Equivalence and non inferiority trials

Many effective drugs, biologics and devices exist. Because of this, it is often considered unethical to undertake placebo controlled clinical trials to evaluate new treatments. Rather, randomized active control noninferiority trials have become the norm. These trials, however, are accompanied by serious issues including selecting an active comparator, identifying previously run active comparato...

Assessing Equivalence and Non-Inferiority

Equivalence and Non-inferiority Trials of CAM

For several reasons, the value of placebo-controlled trials has often been disputed (not only) in complementary/alternative medicine (CAM) (1). Many clinicians feel that giving placebos to suffering patients is unethical. In fact, the Declaration of Helsinki advocates placebo-controlled trials only for conditions for which no therapy of proven efficacy exists (2). Other frequently cited reasons...

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...