Noninferiority clinical trials are designed to determine whether an intervention is not worse than a comparator by a prespecified difference, known as the noninferiority margin (ΔNI). These trials are useful when comparing standard therapies with novel treatments that may be easier to use, are less costly, or have fewer adverse effects.¹ The number of noninferiority trials is increasing; however, particularly compared with superiority trials, the interpretation of noninferiority trials is not straightforward. Superiority trials can be classified as positive or negative based on whether the null hypothesis can be rejected (ie, P < .05). In contrast, noninferiority trials can be interpreted as noninferior, inconclusive, or not noninferior according to the location of the 95% CIs in relation to the prespecified margin (Figure). Inconclusive and not noninferior results are often both presented as “negative” results (eg, failure to meet noninferiority criteria). This can lead readers to erroneously interpret an inconclusive trial as showing evidence that the novel treatment is worse, while in reality the findings are indeterminate and further research is required to determine noninferiority.

非劣效性临床试验旨在通过一种预先确定的差异（即非劣效性余量（ΔNI））来确定一项干预措施是否不比对照者差。当将标准疗法与可能更易于使用，成本更低或副作用更少的新型疗法进行比较时，这些试验非常有用。¹非劣效性试验的数量正在增加；但是，特别是与优势试验相比，非劣效试验的解释并不简单。根据是否可以拒绝原假设（例如，P <.05）。相反，根据95％CI相对于预定边缘的位置，非劣效性试验可解释为劣等，不确定或非劣等（图）。不确定的结果和非劣质的结果通常都表示为“阴性”结果（例如，不满足非劣质性标准）。这可能会导致读者错误地解释一项无结果的试验，因为该试验显示出证据表明这种新型治疗方法较差，而实际上，研究结果尚不确定，需要进一步的研究来确定非劣效性。