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Evidence Synthesis Reviews

What is an umbrella review?

AKA review of reviews​

Evidence synthesis review of existing evidence synthesis reviews​

Ideal if the existing evidence is contradictory ​

Could synthesise together:​

  • Different interventions for the same condition​
  • Different outcomes investigated for the same intervention and condition ​
  • Different conditions, problems or populations

Key features

  • Requires a team ​
  • Closed ended question​
  • Pre-defined eligibility criteria (“a priori”)​
  • Explicit & reproducible methodology ​
  • Attempts to find all existing evidence synthesis reviews​
  • Critical appraisal / risk of bias assessment​
  • Systematic presentation and synthesis of the characteristics and findings of the included studies

Reporting standards

Page M J, McKenzie J E, Bossuyt P M, Boutron I, Hoffmann T C, Mulrow C D et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews BMJ 2021; 372 :n71 https://doi.org/10.1136/bmj.n71

See the PRISMA website for more details

Further resources

Aromataris E, Fernandez R, Godfrey C, Holly C, Khalil H, Tungpunkom P. Umbrella Reviews (2020). Aromataris E, Lockwood C, Porritt K, Pilla B, Jordan Z, editors. JBI Manual for Evidence Synthesis. JBI; 2024. Available from: https://synthesismanual.jbi.global. https://doi.org/10.46658/JBIMES-24-08

Pollock M, Fernandes RM, Becker LA, Pieper D, Hartling L. Chapter V: Overviews of Reviews [last updated August 2023]. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.5. Cochrane, 2024. Available from cochrane.org/handbook.

Library class: Overview of Systematic, Scoping and Other Evidence Synthesis Reviews

Step into the world of evidence synthesis and learn what’s involved in systematic reviews, scoping reviews and more.  

This session provides an overview of various types of evidence synthesis reviews. Learn about the differences in the methodologies, requirements, and processes for Systematic Reviews, Scoping Reviews, and more. Offered by NSLHD Libraries in conjunction with RNS ICU Research’s A/Prof Rosalind Elliott.

Watch a recording of this class 

We also offer the more advanced Undertaking Systematic, Scoping and Other Evidence Synthesis Reviews, parts I and II.