24 June 2019 - Non-inferiority trials imply a trade-off between a loss in efficacy of a standard treatment in exchange for other benefits of a new therapy (eg, easier to use, less costly, fewer adverse effects). 

Non-inferiority studies are increasingly used for comparisons of novel treatments with standard active controls. However, this design is complex; clinicians, patients, and even investigators often have difficulty fully grasping this methodology. 

The importance of anticipated benefits is often not explicitly characterised, and the threshold for the necessary trade-off, called the non-inferiority margin (ΔNI), is sometimes chosen arbitrarily without integrating patient values and preferences.

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