May 2017 Let’s Hear From a Colleague

Non-inferiority trials: Why, what and how?

Mara Therese P. Evangelista, MD and Nicholas Earl Huber

Most clinical trials are designed to show that an experimental intervention, such as a drug or procedure, is superior to an existing intervention (or to no intervention, if none is currently available). These designs are called superiority trials. However, sometimes an experimental intervention is not expected to be clinically superior to an existing product, but has other advantages, such as being cheaper, easier to administer, or has a better safety profile. This latter concept is important in dermatology because some drugs that are considered the standard of care may cause unwanted side effects (e.g. steroids), or are perhaps too expensive or are non-sustainable for some our patients.