The Rise in Meta-analyses from China

To the Editor: Meta-analysis is a statistical technique to combine and summarize the findings of several related studies.1 We searched in PubMed for meta-analysis articles published by Chinese authors and found a 200-fold increase from 2001 to 2011 (from five articles in 2001 to 1,000 in 2011). According to PubMed data, 1.3% of the articles by Chinese researchers in 2011 are meta-analyses, whereas the number is 0.4% for authors from the rest of the world. We also found that some Chinese researchers published meta-analysis articles on topics outside of their own expertise. What is behind this phenomenon? The popularity of meta-analysis corresponds with the recent promotion of evidence-based medicine in China.2 However, we believe that much of this increase in meta-analysis articles may be driven by academic pressures on individual researchers, for whom articles are the most important benchmark for professional promotion. To publish articles, clinicians have to take time from their busy clinical jobs to conduct research. Clinicians urgently need ways to publish articles with the minimum investment of time. Meta-analysis is a shortcut to publish articles. A meta-analysis can be completed by literature research and statistical analysis, without having to design and execute actual research projects. Moreover, once an author completes his first meta-analysis, the next becomes easier. The increasing publication of meta-analyses reflects both the rise of evidence-based medicine in China and the pressure on Chinese researchers to publish articles. Is this a good thing? We believe high-quality meta-analysis should be encouraged. Meta-analysis provides the best evidence for medical practice. Meta-analysis enlarges sample size and produces more representative results than single studies. At the same time, it is important to improve the quality of meta-analyses. Guidelines should be followed, including preferred reporting items for systematic reviews and meta-analyses (PRISMA) for combining randomized clinical trials, and so on. Another way to improve meta-analyses is for researchers to choose meta-analysis topics from their own research areas. Authors who conduct meta-analyses outside their own areas of expertise are unlikely to have the full understanding of the topic that contributes to a well-conducted meta-analysis. Xiao-Fei Ye Department of Health Statistics Second Military Medical University Shanghai, China Dang-Hui Yu Academic Journal of Second Military Medical University Shanghai, China Jia He Department of Health Statistics Second Military Medical University Shanghai, China [email protected]