Meta-analysis of published data is important in evidence-based medicine. However, it is an experiment-free route to rapid publication and so is open to abuse. Extra vigilance by peer reviewers and journal editors is called for to prevent redundant and conflicted meta-analyses from corrupting the literature.
China produced 63% of meta-analyses of genetic associations in 2014, and most of those results are misleading (J. P. A. Ioannidis Milbank Q. 94, 485–514; 2016). Pressure to publish may be responsible, given that doing actual experiments takes much longer and can yield insufficient clinical data. And skilful presentation is often all it takes to disguise a poor-quality meta-analysis.
Conclusions from arbitrarily merging results of variable quality will not resolve problems and should not guide clinical practice. A rigorous meta-analysis requires meticulous evaluation of the literature. And even high-quality meta-analyses in leading journals still need constant clinical testing to ensure that current guidelines for treatment remain valid.
Nature 557, 31 (2018)
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