Specifying the target difference in the primary outcome for a randomised controlled trial: guidance for researchers
Specifying the target difference in the primary outcome for a randomised controlled trial: guidance for researchers
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DOI：
10.1186/s13063-014-0526-8
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发表时间：
2015-01-15
期刊：
影响因子：
2.5
通讯作者：
Vale, Luke D.
中科院分区：
文献类型：
--
作者：
Cook, Jonathan A.;Hislop, Jenni;Vale, Luke D.
背景：随机对照试验设计的核心是计算所需参与者的数量。这通常是通过指定目标差异并计算相应的样本量来实现的，这可以保证试验将具有所需的统计功效（在计划的统计显着性水平）来识别是否存在特定幅度的差异。除了纯粹的统计或科学问题之外，招募适当数量的参与者在道德上也是必要的。尽管主要结局的目标差异在随机对照试验的设计中发挥着关键作用，但其确定却很少受到关注。本文为具有优效性问题的两组平行组随机对照试验的样本量计算中主要结果的目标差异的规范提供了指导。方法：这项工作是 DELTA（试验中的差异诱导）项目的一部分。项目指导和咨询小组利用系统审查和调查的结果制定了指南草案。研究结果在面对面会议上分发给合并小组的成员，同时还提出了指导文件结构的大纲，其中包含试验方案和报告的建议和报告项目。该指南随后被起草并分发，以在最终定稿之前征求进一步意见。结果：制定了关于两组平行随机对照试验主要结果目标差异规范的指南。此外，还生成了方案和试验报告的报告项目列表。结论：主要结果的目标差异的规范是随机对照试验样本量计算的关键组成部分。需要更好地证明目标差异的合理性并报告其规范。
Background: Central to the design of a randomised controlled trial is the calculation of the number of participants needed. This is typically achieved by specifying a target difference and calculating the corresponding sample size, which provides reassurance that the trial will have the required statistical power (at the planned statistical significance level) to identify whether a difference of a particular magnitude exists. Beyond pure statistical or scientific concerns, it is ethically imperative that an appropriate number of participants should be recruited. Despite the critical role of the target difference for the primary outcome in the design of randomised controlled trials, its determination has received surprisingly little attention. This article provides guidance on the specification of the target difference for the primary outcome in a sample size calculation for a two parallel group randomised controlled trial with a superiority question.Methods: This work was part of the DELTA (Difference ELicitation in TriAls) project. Draft guidance was developed by the project steering and advisory groups utilising the results of the systematic review and surveys. Findings were circulated and presented to members of the combined group at a face-to-face meeting, along with a proposed outline of the guidance document structure, containing recommendations and reporting items for a trial protocol and report. The guidance and was subsequently drafted and circulated for further comment before finalisation.Results: Guidance on specification of a target difference in the primary outcome for a two group parallel randomised controlled trial was produced. Additionally, a list of reporting items for protocols and trial reports was generated.Conclusions: Specification of the target difference for the primary outcome is a key component of a randomized controlled trial sample size calculation. There is a need for better justification of the target difference and reporting of its specification.