Efficacy of a new drug or treatment is usually established through randomized clinical trials. However, specifying hypotheses remains a challenging problem for biomedical researchers. In this survey we discuss superiority, non-inferiority, and equivalence trials. These three types of trials have different assumptions on treatment effects. We compare the assumptions underlying these trials and provide sample size formulas.
一种新型药物或治疗的效果通常是通过临床随机对照试验获得的。然而，假设的设定对生物医学研究者来说仍然是具有挑战性的问题。在本调查中，我们讨论了有效性试验、非劣效性试验、和等效性试验。这三类试验对治疗效果均有不同的假设。我们比较了这些试验中的假设并提供了样本量计算公式。.
Keywords: Randomized clinical trial; margin of clinical significance; sample size calculation.