| 唐金陵,杨祖耀,毛琛.大型随机对照试验:精准流行病学研究的典范与陷阱[J].Chinese journal of Epidemiology,2017,38(10):1299-1304 |
| 大型随机对照试验:精准流行病学研究的典范与陷阱 |
| The use and pitfalls of large randomized controlled trials |
| Received:May 23, 2017 |
| DOI：10.3760/cma.j.issn.0254-6450.2017.10.001 |
| KeyWord: 研究设计 临床试验 大型随机对照试验 偏倚 样本量 |
| English Key Word: Study design Clinical trial Large randomized controlled trial Bias Sample size |
| FundProject:国家自然科学基金（81273171） |
| Author Name | Affiliation | E-mail | | Tang Jinling | Division of Epidemiology, School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR 999077, China | jltang@cuhk.edu.hk | | Yang Zuyao | Division of Epidemiology, School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR 999077, China | | | Mao Chen | Division of Epidemiology, School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR 999077, China | |
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| Abstract: |
| 现代流行病学是医学应用型研究的方法论，是在人群中定量地研究有关健康、疾病和医疗服务实践问题一般规律的科学和艺术。流行病学研究结果的准确度主要取决于研究的设计类型，精确度主要取决于样本量大小。大型随机对照试验是最精、最准的流行病学研究设计类型，但是由于伦理的限制，只能用于评估医学干预效果。一项研究需要的设计严谨性和样本量与预期效果的大小成反比：效果越小，所需的研究设计就越严谨，需要的样本量就越大。因此，只有当疗效比较小时，才需要大型随机对照试验，当疗效十分明显时，中小型随机对照试验甚至观察性研究就足以证明其有效性。从研究阶段上看，它是确认性、终结性研究，而不是提出假设的原创性研究。然而，研究的价值最终取决于研究问题的意义和原创性，而不是研究方法和P值的大小。过度推崇大型随机对照试验会引发：①对中、小疗效干预的过度强调；②对确认性研究的过度重视，以及对项目大小和经费多少而不是科学问题的追逐，进而弱化原创性研究工作；③增加研究资源、医学活动和患者利益被制药公司绑架的风险。 |
| English Abstract: |
| Modern epidemiology is the art and science of investigating quantitatively regularities or general laws regarding applied healthcare issues. The validity of epidemiological studies is primarily determined by the study design and the precision by the sample size. Large randomized controlled trial (RCT) is thus the most rigorous and most precise epidemiological study design. Due to ethical concerns, RCTs can however be used only to evaluate medical interventions. Rigorousness of study design and sample size required for a study are inversely related to the anticipated size of effect to be evaluated:the smaller the effect, the more rigorous the study design and larger the sample size are required. Thus, large RCTs are necessary and called upon when and only when the effectiveness to be proved is relatively small; large effectiveness can be verified with small or medium-sized RCTs or even observational studies. In the stages of scientific research, large RCTs are confirmatory rather than original investigations on new hypotheses, whereas the value of a study is ultimately determined by the importance and novelty of the research question rather than methodology and the P value. Overemphasis on large RCTs has been causing:1) overemphasis on interventions of small or moderate effect; 2) overemphasis on confirmatory studies and on size of study and funding and weakening original creative work; 3) increasing the risk of research resources, medical activities, and patients' well-being being hijacked by pharmaceutical companies. |
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