Subject and Course Guides: Systematic Reviews: Existing Reviews

Identify existing reviews

An important and very helpful part of the protocol process is identifying previously published reviews. Search for Systematic Reviews, Scoping Reviews, and Meta-analyses related to your topic. These evidence syntheses may provide a model for approaching your own review, including recommended search strategies and resources. Additionally, searching for existing reviews can:

Give you an idea of what makes a publishable review (especially if you find them in your target journal)
Help identify important key terms for search strategy development
Help identify essential databases for search strategy development
Help identify important journals for hand searching
Help identify important sources of gray literature
Identify relevant papers for inclusion in your review

*Note: be sure to include similar reviews in your introductory materials and be prepared to explain why your review is different

Finding Existing Systematic Reviews

Systematic reviews and review protocols are registered with a variety of organizations.

For Medical Reviews

Cochran Library
Database of reviews in Medicine and healthcare produced by Cochran Review Groups
PROSPERO
PROSPERO is an international database of prospectively registered systematic reviews which involve health related outcomes
Joanna Briggs Institute
Registered systematic reviews thats are currently underway at Joanna Briggs Institute
Trip
A search engine for clinical research evidence
SYREAF
A database of systematic reviews for Animals and Food

For Social Social Science Reviews

Campbell Collaboration
A database of Campbell Reviews pertaining to the social sciences
Health Evidence
Search this site for systematic reviews researching public health outcomes
Epistemonikos
Search here for evidence based healthcare reviews
The Community Guide
Guide to Community Preventive Services is a collection of reviews that can be used to determine which interventions produce a positive related health outcome
3iE
International Initiative for Impact Evaluation (3ie) supports studies and reviews that examine what works in international development in low and middle income countries
EPPI Centre
The Evidence for Policy and Practice Information and Co-ordinating Centre conducts systematic reviews in the fields of Education, including Initial Teacher Education (ITE), Health Promotion and Public Health, as well as social welfare and international development

For Environmental Science Reviews

Collaboration for Environmental Evidence
Database of all systematic reviews approved by Collaboration for Environmental Evidence on environmental policy and practice

Other Sources

Research Registry
A registry for all types of research studies
Open Science Framework
Open platform that supports registry and discovery of research

Appraising Existing Evidence Syntheses

Just because a review has been published, it does not imply that the review was rigorous, reproducible or exhaustive. There are a number of criteria by which you can assess the quality of an evidence synthesis. Below are the two most common tools used for this purpose.