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What is non-inferiority design?
By definition, a non-inferiority trial aims to demonstrate that the test product is not worse than the comparator by more than a small pre-specified amount. This amount is known as the non-inferiority margin, or delta. Clinicians must know who has chosen the margin, and why.
What is a non-inferiority test?
A study that tests whether a new treatment is not worse than an active treatment it is being compared to. Non-inferiority trials are sometimes done when a placebo (an inactive treatment) cannot be used.
How is non-inferiority determined?
The noninferiority margin is determined by halving the control effect, based on a historical placebo-controlled trial.
When to use a non inferiority trial design?
The non-inferiority trial design has gained popularity within the last decades to compare a new treatment to the standard active control. In contrast to superiority trials, this design is complex and is based on assumptions that cannot be validated directly.
When do you include a non inferiority margin?
A non-inferiority trial has the same principle, but an additional non-inferiority margin is included. This margin quantifies when the new therapy is considered to be non-inferior to the standard therapy.
When is a statistical test for noninferiority inconclusive?
Paradoxically, both noninferiority and inferiority are demonstrated if the statistical test for noninferiority is met but the confidence interval is above 1. The results are inconclusive if the confidence interval includes the noninferiority margin and does not exclude 1, a finding that suggests an underpowered comparison.
What are the major components of noninferiority study design?
The following major components of noninferiority study design are listed in Table 1. First, the foundation of the noninferiority trial is one or more prior randomized trials evaluating the superiority of the active control over placebo.