The quest for reviews suitable for inclusion in an umbrella review, an overview of reviews or in a meta-epidemiological study is a crucial step to ensure the validity of findings of evidence syntheses as well as to minimise publication bias or similar threats to accuracy. Dedicated databases are obviously a key starting point, such as the Cochrane Database of Systematic Reviews (CDSR) and the Database of Abstracts of Reviews of Effects (DARE). Then, established filters can be used to search the more comprehensive, but potentially too extensive, general literature databases, such as MEDLINE/PubMed and Embase. Careful and early collaboration with an information specialist is recommended to optimise the yield and minimise the effort of searching evidence for an umbrella review.
KeywordsDatabase search Publication bias Reporting bias Search Search strategy
We would like to thank Julie Glanville, YHEC, for comments on an earlier draft.
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