Ioannidis J P, Lau J
Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Greece.
Jt Comm J Qual Improv. 1999 Sep;25(9):462-9. doi: 10.1016/s1070-3241(16)30460-6.
Meta-analysis, the systematic and quantitative synthesis of evidence, has developed considerably in the 1990s and is emerging as an important methodology in medical decision making. As a research methodology, meta-analysis has benefits and limitations that must be acknowledged in its application.
The benefits of meta-analysis include the ability to improve the power of small or inconclusive studies to answer questions and the ability to identify sources of diversity across various types of studies. Meta-analysis may reveal how heterogeneity among populations affects the effectiveness of medical interventions in different settings and in different patients. It can also help detect biases, such as publication bias and "Tower of Babel" bias, as well as deficiencies in the design, conduct, analysis, and interpretation of research. In this way, it can also stimulate improvements in the quality of the data needed to optimize medical care.
Meta-analysis cannot improve the quality or reporting of the original studies. Other limitations come from misapplications of the method, such as when study diversity is ignored or mishandled in the analysis or when the variability of patient populations, the quality of the data, and the potential for underlying biases are not addressed.
Meta-analysis has promoted the sense that obtaining evidence is a global enterprise and that complete information needs to be evaluated and synthesized to obtain the most unbiased results. Analyzing sources of bias and diversity is essential to performing, understanding, and using meta-analyses in medical care.
荟萃分析作为对证据进行系统和定量综合的方法，在20世纪90年代有了很大发展，并正在成为医学决策中的一种重要方法。作为一种研究方法，荟萃分析有其优点和局限性，在应用中必须予以承认。
荟萃分析的优点包括能够提高小型或无定论研究回答问题的能力，以及能够识别各类研究中的差异来源。荟萃分析可以揭示不同人群之间的异质性如何影响不同环境和不同患者中医疗干预的效果。它还可以帮助检测偏倚，如发表偏倚和“巴别塔”偏倚，以及研究设计、实施、分析和解释中的缺陷。通过这种方式，它还可以促进优化医疗所需数据质量的提高。
荟萃分析无法提高原始研究的质量或报告水平。其他局限性源于该方法的错误应用，例如在分析中忽略或错误处理研究的多样性，或者未考虑患者人群的变异性、数据质量以及潜在偏倚的可能性。
荟萃分析促进了这样一种观念，即获取证据是一项全球性事业，需要对完整信息进行评估和综合，以获得最无偏倚的结果。分析偏倚和差异来源对于在医疗保健中进行、理解和使用荟萃分析至关重要。
