## How can you differentiate between superiority and non-inferiority clinical trial?

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.

**Can you show superiority in a non-inferiority trial?**

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 superiority clinical trials?

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 a non-inferiority clinical trial?**

A study that tests whether a new treatment is not worse than an active treatment it is being compared to. Non-inferiority trials are sometimes done when a placebo (an inactive treatment) cannot be used.

## Can a non-inferiority trial show equivalence?

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. An equivalence boundary should be set before the trial. This is the definition of what would be the minimum important difference between the treatments.

**What is equivalence clinical trial?**

In an equivalence trial, the statistical test aims at showing that two treatments are not too different in characteristics, where “not too different” is defined in a clinical manner. Finally, in a non-inferiority trial, the aim is to show that an experimental treatment is not (much) worse than a standard treatment.

### Is non-inferiority the same as equivalence?

**What is an equivalence trial?**

Equivalence trials compare a new treatment for a disease or condition with an existing treatment—usually the standard one. Treatments that have already been shown to be effective are referred to as active controls when used as a control treatment in a trial (a is true).

## What is a equivalence trial?

**What is a non-inferiority limit?**

In fact a non- inferiority trial aims to demonstrate that the test product is not worse than the comparator by more than a pre-specified, small amount. This amount is known as the non-inferiority margin, or delta (∆).

### How do you calculate sample size for non-inferiority trials?

The sample size required for a non-inferiority clinical trial can be calculated using the formula in Figure 1 [5],[6]. Table 4 gives common Normal deviates for different percentiles. For example, for β = 0.1, we would have x = 0.1 and Z1-x = 1.282, while for α = 0.05, we would have x = 0.025 and Z1-x = 1.96.

**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 …