Meta-analysis Spurious precision? Meta-analysis of observational studies
Meta-analysis Spurious precision? Meta-analysis of observational studies
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DOI：
10.1136/bmj.316.7125.140
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发表时间：
1998-01
期刊：
影响因子：
--
通讯作者：
M. Egger;Martin Schneider;G. Smith
中科院分区：
文献类型：
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作者：
M. Egger;Martin Schneider;G. Smith
在以前的文章中，我们已经集中在随机对照试验的荟萃分析的潜力，原则和陷阱。1 2 3 4 5然而，观察数据的荟萃分析也变得越来越普遍。在Medline检索中，我们确定了1995年发表的566篇文章（不包括以信件形式发表的文章），并以医学主题词（MeSH）术语“荟萃分析”进行索引。我们随机选择了其中的100篇文章，并对其进行了进一步的研究。60篇文章报告了实际的荟萃分析，40篇是方法学论文、社论和传统综述（1）。在荟萃分析中，大约一半是基于观察性研究，主要是医疗干预或病因学关联的队列和病例对照研究。查看此表：从1995年发表的文章中随机选择100篇文章，并在Medline中以关键词“荟萃分析”进行索引。随机对照试验是评价医疗干预措施的主要研究设计。然而，病因学假设--例如，那些与疾病发生有关的常见暴露--通常不能在随机实验中进行检验。吸别人的烟会导致肺癌吗？喝咖啡会导致冠心病吗？吃富含饱和脂肪的食物会导致乳腺癌吗？对这种“日常生活的威胁“的研究6采用观察设计或在实验室中检查假定的生物机制。在这些情况下，所涉及的风险通常很小，但一旦大部分人口暴露于这些风险中，这些关联的潜在公共卫生影响（如果它们是可预测的）可能是惊人的。对观察数据的分析也在医疗有效性研究中发挥作用。7从临床试验中获得的证据很少能回答所有重要的问题。大多数试验是为了确定单一药物在特定临床情况下的疗效和安全性而进行的。由于此类试验的规模有限，药物的不太常见的不良反应可能只能在病例对照试验中发现。
In previous articles we have focused on the potentials, principles, and pitfalls of meta-analysis of randomised controlled trials.1 2 3 4 5 Meta-analysis of observational data is, however, also becoming common. In a Medline search we identified 566 articles (excluding those published as letters) published in 1995 and indexed with the medical subject heading (MeSH) term “meta-analysis.” We randomly selected 100 of these articles and examined them further. Sixty articles reported on actual meta-analyses, and 40 were methodological papers, editorials, and traditional reviews (1). Among the meta-analyses, about half were based on observational studies, mainly cohort and case-control studies of medical interventions or aetiological associations. View this table: Characteristics of 100 articles randomly selected from articles published in 1995 and indexed in Medline with keyword “meta-analysis” The randomised controlled trial is the principal research design in the evaluation of medical interventions. However, aetiological hypotheses—for example, those relating common exposures to the occurrence of disease—cannot generally be tested in randomised experiments. Does breathing other people's tobacco smoke cause lung cancer, drinking coffee cause coronary heart disease, and eating a diet rich in saturated fat cause breast cancer? Studies of such “menaces of daily life”6 use observational designs or examine the presumed biological mechanisms in the laboratory. In these situations the risks involved are generally small, but once a large proportion of the population is exposed, the potential public health implications of these associations—if they are causal—can be striking. Analyses of observational data also have a role in medical effectiveness research.7 The evidence available from clinical trials will rarely answer all the important questions. Most trials are conducted to establish efficacy and safety of a single agent in a specific clinical situation. Owing to the limited size of such trials, less common adverse effects of drugs may only be detected in case-control …