Claims of equivalence in medical research: Are they supported by the evidence?
Claims of equivalence in medical research: Are they supported by the evidence?
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DOI：
10.7326/0003-4819-132-9-200005020-00006
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发表时间：
2000-05-02
影响因子：
39.2
通讯作者：
Feinstein, AR
中科院分区：
文献类型：
--
作者：
Greene, WL;Concato, J;Feinstein, AR
背景：大多数临床研究是为了显示比较优势，但许多报告现在声称研究实体之间的等效性。这些断言可能并不总是得到所使用的方法和获得的结果的支持。目的：评估医学期刊中临床或治疗等效性声明的合理性和支持。数据来源：MEDLINE检索1992年至1996年发表的文章。研究选择：从标题或摘要中包含“等效性”一词或包含“医学主题标题治疗等效性”的1209篇引文中，我们排除了1121项报告非原创研究的研究，纯实验室或其他非人类研究，以及等效性不是主要要求的研究。其余88个合格的论文进行了评估，为五个方法attributes.Data合成：只有45（51%）的88份报告是专门针对研究等效性，其他人要么试图显示优越性或没有说明一个研究目的。被视为“等同”的数量差异范围为：直接递增为0%至21%，比例差异为0%至76%。仅在23%的报告中设定了等效性边界，并通过适当的统计检验进行了确认。在67%的报告中，在比较优效性检验失败后宣布等效，在10%的报告中，未对等效性声明进行统计学评价。只有33%的报告提前计算了确认结果所需的样本量。样本量为每组20例或更少的25%的reports.Conclusions：许多临床等效性研究不设置等效性的界限。声称“不同”或“相似”往往不是通过对数据进行深思熟虑的检查，而是通过统计显著性的检验，这些检验往往被误用或伴随着样本量不足。这些方法上的缺陷可能导致错误的声明，不一致和对患者的伤害。
Background: Most clinical studies are done to show comparative superiority, but many reports now claim equivalence between the investigated entities. These assertions may not always be supported by the methods used and the results obtained.Purpose: To assess the justification and support for claims of clinical or therapeutic equivalence in medical journals.Data Sources: A search of MEDLINE for articles published from 1992 through 1996.Study Selection: From 1209 citations that contained the word equivalence in the title or abstract or contained the Medical Subject Heading therapeutic equivalency, we excluded 1121 studies reporting nonoriginal research, purely laboratory or other nonhuman research, and studies in which equivalence was not the main claim. The remaining 88 eligible papers were evaluated for five methodologic attributes.Data Synthesis: Only 45 (51%) of the 88 reports were specifically aimed at studying equivalence; the others either tried to show superiority or did not state a research aim. The quantitative distinctions regarded as "equivalent" ranged from 0% to 21% for direct increments and from 0% to 76% for proportionate differences. An equivalence boundary was set and confirmed with an appropriate statistical test in only 23% of reports. In 67% of reports, equivalence was declared after a failed test for comparative superiority, and in 10%, the claim of equivalence was not statistically evaluated. The sample size needed to confirm results had been calculated in advance for only 33% of reports. Sample size was 20 patients per group or fewer in 25% of reports.Conclusions: Many studies of clinical equivalence do not set boundaries for equivalence. Claims of "difference" or "similarity" are often made not by thoughtful examination of the data but by tests of statistical significance that are often misapplied or accompanied by inadequate sample sizes. These methodologic flaws can lead to false claims, inconsistencies, and harm to patients.