What is the difference between a non-inferiority trial and a superiority trial?
A superiority trial is designed to show that a new treatment is better than an active control or placebo. A non-inferiority trial is different as it is designed not to show that treatments are equal, or ‘not different’, but that the new treatment is not unacceptably worse than, or ‘non-inferior’ to, an active control.
Can non-inferiority trials show superiority?
In a non-inferiority trial, the focus is on the lower bound margin, what happens at the upper end is not of primary concern in this type of trial design. One can also declare superiority in a non-inferiority trial if the lower limit of CI of the new treatment is above the non-inferiority margin and above zero.
What is a superiority trial?
A superiority trial is designed to detect a difference between treatments. The first step of the analysis is usually a test of statistical significance to evaluate whether the results of the trial are consistent with the assumption of there being no difference in the clinical effect of the two treatments.
What is the difference between non-inferiority and equivalence trials?
Non-inferiority trials aim to show that the new drug is no worse than standard treatment. Equivalence trials aim to show the new treatment is no better and no worse. This is the definition of what would be the minimum important difference between the treatments.
What is superiority and inferiority?
inferiority complex. A superiority complex is an exaggerated sense of self-worth. It hides real feelings of mediocrity. An inferiority complex is an overstated feeling of weakness. It often hides true motives, such as aspirations for power.
What is a Phase 3 superiority trial?
Most phase III trials aim to demonstrate the superiority of a new treatment in comparison with control; however, phase III trials may also assess whether a more convenient, less toxic, or more affordable intervention is at least as efficacious as an existing standard of care, and these are called non-inferiority trials …
What is an acceptable noninferiority margin?
In order to demonstrate non-inferiority, the recommended approach is to pre-specify a margin of non- inferiority in the protocol. After study completion, a two-sided 95% confidence interval (or one-sided 97.5% interval) for the true difference between the two agents will be constructed.
What is inferiority trial?
If the intent of a study is to demonstrate that an experimental treatment is not substantially worse than a control treatment, the study is known as a noninferiority trial.
What is superiority margin?
There is a percentage above 70% at which the difference between the two treatments is no longer considered ignorable. The difference between these two percentages is called the margin of superiority.
What is the difference between inferiority feelings and the inferiority complex?
Most people have heard of inferiority complexes. Adler explained there was an important difference between inferiority feelings, which are universal and serve as a positive motivating force, and inferiority complexes, which are relatively rare and tend to paralyze people rather than motivating them.
What phase is a non-inferiority trial?
A non-inferiority phase III trial requires a roughly four times larger sample size than that of a similar standard superiority trial. Because of the large required sample size, we often face feasibility issues to open a non-inferiority trial.
What is the difference between non-inferiority and superiority trials?
Non-inferiority studies are used to show that a minimum level of efficacy has been achieved. In comparison studies with a current therapy, non-inferiority is used to demonstrate that the new therapy provides at least the same benefit to the patient. Superiority trials are always used when comparisons are made to placebo or vehicle treatments.
Are superiority and non-inferiority phase 3 trials two sides of the same coin?
Guidelines and statistical practice should abandon the sharp division between superiority and non-inferiority phase 3 non-regulatory trials and be more closely aligned to the clinical and public health questions that motivate the trial. Superiority and non-inferiority: two sides of the same coin? Trials.
What is a superiority test in a randomized controlled trial?
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.
Does a nonsignificant superiority test prove no difference between treatments?
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 statistical tools; at most, one can show that they are equivalent.