Design and interpretation of non-inferiority studies: A clinician’s perspective

Excerpt

The placebo-controlled, randomized clinical trial has long been considered the gold standard for establishing the efficacy of a new drug or treatment.1 Well validated statistical methods for the design, analysis, and interpretation of these studies exist, and clinicians are, in general, comfortable reading, interpreting, and applying data from these types of clinical trials into clinical practice. In these studies, investigators attempt to demonstrate the superior efficacy (superiority) of the new drug or treatment over placebo. However, frequently, there are scenarios which prohibit the use of a placebo-controlled, randomized clinical trial. In these situations, investigators are forced to compare the experimental therapy to an established treatment, referred to as an active comparison group, rather than placebo. Although investigators may choose to attempt to demonstrate superiority of the experimental treatment over the active comparison, in recent years, there has been an increase in the number of clinical trials that simply attempt to demonstrate the non-inferiority of this new therapy.1-8 In this manuscript, I will summarize the role, design, and interpretation of this type of a clinical trial. …