In an equivalence trial, what is the primary objective?

In an equivalence trial, the primary objective is to demonstrate that the effects of two treatments are similar enough that they can be considered equivalent within a predefined margin. This means showing that there are no statistically significant differences in the responses to the treatments being compared.

The focus is on establishing that the new treatment is not significantly worse than the standard treatment, allowing for conclusions that the two can be used interchangeably in practice. Such a design is essential when a new treatment aims to offer similar efficacy with possibly different safety or administration profiles.

While investigating safety profiles, evaluating long-term outcomes, and proving superiority are essential aspects of clinical research, they do not define the specific goal of equivalence trials. Hence, the core aim is the assessment of similarity rather than superiority or detailed safety evaluations.