A trial design aiming to assess whether a test product is not inferior to a comparator.
Non-inferiority is defined as efficacy that is no lower than a small pre-specified value, known as the non-inferiority margin. This margin must be specified in advance and based on clinical and statistical data; choice of non-inferiority margin can be challenging, and regulatory agencies have published extensive guidance to inform trial design.
The following page has an accessible guide to non-inferiority: What is a Non-inferiority Clinical Trial? (Quantics Biostatistics, 2018)