Users’ guide to the surgical literature: how to assess a noninferiority trial

SUMMARY: A well-planned randomized controlled trial (RCT) is the most optimal study design to determine if a novel surgical intervention is any different than a prevailing one. Traditionally, when we want to show that a new surgical intervention is superior to a standard one, we analyze data from an RCT to see if the null hypothesis of "no difference" can be rejected (i.e., the 2 surgical interventions have the same effect). A noninferiority RCT design seeks to determine whether a new intervention is not worse than a prevailing (standard) one within an acceptable margin of risk or benefit, referred to as the "noninferiority margin." In the last decade, we have observed an increase in the publication of noninferiority RCTs. This article explores this type of study design and discusses the tools that can be used to appraise such a study.