Meta-analysis in the era of big data

Excerpt

Systematic reviews (SR) and meta-analyses (MA) are crucial to synthesize the enormous amount of information gathered to answer specific questions. This synthesis is extremely valuable in order to make decisions, as it allows to get rid of all the noise caused by individual studies. SR are essentially reviews of the published—and unpublished—evidence that follow well-developed guidelines to avoid bias while ensuring maximal reproducibility and transparency. MA statistically combine the results of multiple studies addressing the same question. Due to their relevance and their immediate applicability in decision-making, MA need to be conducted and interpreted with a strict methodology. Such methodology includes selecting in a transparent way the sources of evidence, critically appraising the potential biases of individual studies, and making explicit arguments in favour of combining the data before actually pooling them. The reader should be able to judge whether all relevant and valid sources of evidence were included. They must be transparent about how their conclusions are generated to avoid misrepresentation of the knowledge base. …