大型试验与较小试验的元分析:它们的结果如何比较?
J C Cappelleri1, J P Ioannidis, C H Schmid
1Division of Clinical Care Research, New England Medical Center, Boston, Mass. 02111, USA.
JAMA
|October 23, 1996
概括
大规模的临床试验和聚合的较小试验通常一致,但可能会出现差异. 临床上显著的差异很少见,因此需要进一步研究研究类型之间的异质性.
科学领域:
- 临床试验方法论 临床试验方法论
- 超分析研究研究的研究.
背景情况:
- 评估大规模临床试验和较小研究的综合分析之间的一致性对于基于证据的医学至关重要.
- 之前的研究还没有完全探索不同研究大小的结果的一致性.
研究的目的:
- 将大型临床试验的结果与来自多个较小试验的综合结果进行比较.
- 确定大小研究结果之间的差异的频率和潜在原因.
主要方法:
- 系统搜索从主要数据库中确定了至少有一个大型研究 (≥1000名患者) 的元分析.
- 使用了两种选择方法:样本大小和统计能力.
- 随机效应模型主要用于分析,而固定效应模型用于比较.
主要成果:
- 在使用随机效应模型时,在大型和小型试验之间观察到很高的一致性 (90%和82%).
- 对于固定效应模型来说,分歧更频繁,这凸显了考虑到研究变异性的重要性.
- 不一致的可信解释包括对照事件率的差异,研究协议和潜在的出版偏差.
结论:
- 较小的研究结果通常与大型试验一致,尽管偶尔存在差异.
- 研究类型之间的临床显著差异不常见,并且往往是可以解释的.
- 建议进一步调查大试验和小试验之间的异质性来源.
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