Ioannidis J P, Schmid C H, Lau J
Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Greece.
Hematol Oncol Clin North Am. 2000 Aug;14(4):973-91. doi: 10.1016/s0889-8588(05)70322-1.
In 1992, a review article about meta-analysis identified only 15 meta-analyses of randomized, controlled trials of cancer therapy. Since then, the total number of meta-analyses in this field has increased almost sixfold. More importantly, the number of randomized, controlled trials in this discipline has also grown tremendously. The expansion in the literature will provide a fertile ground for future meta-analyses. The quality of the recent publications has also improved. An ongoing world-wide effort, the Cochrane Collaboration, is systematically assembling and synthesizing several hundred thousand randomized, controlled trials to improve the delivery of health care. Meta-analysis has many important advantages. It allows the viewing of the complete picture of the evidence. The advent of meta-analysis has sensitized researchers to issues of quality and has improved methodology in clinical research. Detection and explanation of bias and heterogeneity are prime objectives of meta-analysis in clinical research. An array of methods has been developed that allows a better understanding of bias and heterogeneity, beyond simple averaging of results from diverse studies. Meta-analyses of individual patient data, in particular, may promote the development of international collaborations. Several examples of their application are already available in oncology. Meta-analysis may point out deficiencies in the study design of past and current studies, suggest the need for new studies, and inform researchers about the size and design of these studies. In the end, meta-analysis helps to integrate evidence and make recommendations for medical care and medical practice.
1992年，一篇关于荟萃分析的综述文章仅识别出15项针对癌症治疗随机对照试验的荟萃分析。从那时起，该领域荟萃分析的总数几乎增长了六倍。更重要的是，该学科随机对照试验的数量也大幅增加。文献的扩充将为未来的荟萃分析提供肥沃的土壤。近期出版物的质量也有所提高。一项正在进行的全球行动——Cochrane协作网，正在系统地收集和综合几十万项随机对照试验，以改善医疗保健的提供。荟萃分析有许多重要优势。它能让人全面了解证据情况。荟萃分析的出现使研究人员对质量问题更加敏感，并改进了临床研究方法。检测和解释偏倚及异质性是临床研究中荟萃分析的主要目标。已经开发出一系列方法，除了对不同研究结果进行简单平均之外，还能更好地理解偏倚和异质性。特别是个体患者数据的荟萃分析，可能会促进国际合作的发展。其应用的几个例子在肿瘤学领域已经有了。荟萃分析可能会指出过去和当前研究在研究设计上的不足，表明开展新研究的必要性，并告知研究人员这些研究的规模和设计。最终，荟萃分析有助于整合证据，并为医疗保健和医疗实践提出建议。
