ABSTRACT
If the effect of an experimental therapy on an endpoint is either better than or not too much worse than the effect of a control therapy on that same endpoint, the experimental therapy’s effect is said to be noninferior to the effect of the control therapy. It is common to say that the experimental therapy is noninferior to the control therapy. A clinical trial comparing an experimental arm with a control arm to determine whether the experimental arm is noninferior to the control arm is often called a “non-inferiority trial.” The phrase “at least equivalent as” has also been used instead of “noninferior.” We will use “noninferior” throughout this book.
