What is a systematic review?
“A systematic review attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a given research question. Researchers conducting systematic reviews use explicit methods aimed at minimizing bias, in order to produce more reliable findings that can be used to inform decision making.”
Systematic review services at Galter Library
We recommend you consult with a librarian at the outset of your project, when you are planning your review. Galter librarians can collaborate with you to:
- Formulate your research question.
- Investigate whether there is already a published systematic review on your topic or whether there is one currently under development.
- Plan the search and write the search methods for your review protocol.
- Determine which sources to search and develop sensitive search strategies for each source.
- Identify appropriate search filters and execute the searches.
- Deliver de-duplicated search results in a mutually agreed upon format (e.g. EndNote, RIS, Word).
- Identify tools and strategies to capture the data for the PRISMA flow diagram.
- Document the search process for reporting purposes.
- Write the search methods of the review.
Librarians collaborating on systematic reviews commonly satisfy the criteria for authorship set forth by ICMJE. Co-authorship is expected when a librarian serves as colloborator rather than a consultant. If your project is in support of a grant proposal, plan to discuss the appropriate allocation of effort and include the librarian as a co-investigator or consultant.
Galter Library does not offer assistance pertaining to meta-analysis or meta-analytic methods. Contact the Biostatistics Collaboration Center for inquiries regarding meta-analysis.
What do you need before you get started on your review?
Do you have appropriate expertise in all the required domains for completing a rigorous review? Ideally, your team should include subject specialists, a systematic review methods expert, a librarian or information specialist with training in systematic review methods, and a quantitative methods/meta-analysis specialist (IOM 2011).
This is not an endeavor for the faint of heart. Depending on the subject matter, experience of the review team, commitments to other projects, and other factors, systematic reviews can take a year or more from start to finish. When assembling a team, you should always take these considerations into account and plan your milestones accordingly.
Remember that your systematic review should attempt to identify all of the existing evidence addressing your topic. To cast as broad a net as possible and minimize risk of bias, you will need to search for studies in multiple bibliographic databases, clinical trials registers, and other sources as appropriate. The Cochrane Handbook lists MEDLINE (PubMed or Ovid), EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) as the most important bibilographic databases for identifying trials (Lefebvre 2011). Depending on the subject matter of the review, you might also consider PsycINFO, CINAHL, and other specialized subject or geographic indexes. Be sure to consult with your librarian or information specialist when planning the search methods for your review protocol.
IOM (Institute of Medicine). (2011). Finding What Works in Health Care: Standards for Systematic Reviews. Retrieved from: http://www.iom.edu/Reports/2011/Finding-What-Works-in-Health-Care-Standards-for-systematic-Reviews.aspx.
Lefebvre C, Manheimer E, Glanville J. Chapter 6: Searching for studies. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from http://handbook.cochrane.org/.
The systematic review process
- Define a focused and relevant research question.
- Conduct a preliminary search to determine whether there are any existing systematic reviews that already address your research question. We suggest searching the Cochrane Database of Systematic Reviews, Epistemonikos, PROSPERO, and PubMed with an appropriate systematic review filter, e.g. systematic[sb].
- Assemble a project team.
- Write a review protocol specifying your plan for conducting the review. It should include the rationale for the review, objectives of the review, inclusion/exclusion criteria, methods for locating studies, quality assessment methods, data extraction methods, data synthesis/meta-analysis methods, etc.
- Register your protocol with PROSPERO, Systematic Reviews, or other appropriate entity.
- Search for studies.
- Screen titles and abstracts to identify potentially relevant studies.
- Review full-text and apply inclusion and exclusion criteria.
- Assess quality of eligible studies.
- Extract data from individual studies.
- Analyze data (and synthethize if appropriate).
- Report findings.
Standards and guidance
Here are some standards and additional research synthesis methods papers to get you started:
Atkinson KM, Koenka AC, Sanchez CE, Moshontz H, Cooper H. Reporting standards for literature searches and report inclusion criteria: making research syntheses more transparent and easy to replicate. Res Synth Methods. 2015 Mar;6(1):87-95.doi: 10.1002/jrsm.1127. PubMed PMID: 26035472. Available from: http://onlinelibrary.wiley.com/wol1/doi/10.1002/jrsm.1127/abstract
European Network for Health Technology Assessment. (2015) Guideline: Process of information retrieval for systematic reviews and health technology assessments on clinical effectiveness. JUL 2015. Available from: http://www.eunethta.eu/outputs/eunethta-methodological-guideline-process-information-retrieval-systematic-reviews-and-healt.
Higgins J., Green S., & (editors). (2011). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. J. Higgins & S. Green (Eds.), Available from: http://handbook.cochrane.org/.
Higgins J., Lasserson T., Chandler J., Tovey D., Churchill R. (2016). Methodological Expectations of Cochrane Intervention Reviews (MECIR). Available from: http://methods.cochrane.org/mecir.
IOM (Institute of Medicine). (2011). Finding What Works in Health Care: Standards for Systematic Reviews. Available from: https://www.ncbi.nlm.nih.gov/books/NBK209518/.
Liberati A., Altman D. G., Tetzlaff J., Mulrow C., Gotzsche P. C., Ioannidis J. P., . . . Moher D. (2009). The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. PLoS Medicine, 6(7), e1000100. doi: 10.1371/journal.pmed.1000100. Available from: http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1000100.
Moher D., Liberati A., Tetzlaff J., Altman D. G., & Prisma Group. (2009). Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Medicine, 6(7), e1000097. doi: 10.1371/journal.pmed.1000097. Available from: http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1000097.
Moher D., Shamseer L., Clarke M., Ghersi D., Liberati A., Petticrew M., . . . PRISMA-P Group (2015). Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Systematic Reviews, 4(1), doi:10.1186/2046-4053-4-1. Available from: http://systematicreviewsjournal.biomedcentral.com/articles/10.1186/2046-4053-4-1.
Rader T., Mann M., Stansfield C., Cooper C., & Sampson M. (2013). Methods for documenting systematic review searches: a discussion of common issues. Research Synthesis Methods, Article first published online: 8 OCT 2013. doi: 10.1002/jrsm.1097. Available from: http://onlinelibrary.wiley.com/doi/10.1002/jrsm.1097/abstract.
Rethlefsen M. L., Murad M., & Livingston E. H. (2014). Engaging medical librarians to improve the quality of review articles. JAMA, 312(10), 999-1000. doi: 10.1001/jama.2014.9263. Available from: http://jama.jamanetwork.com/article.aspx?articleid=1902238.
Shamseer L., Moher D., Clarke M., Ghersi D., Liberati A. D., Petticrew M., . . . PRISMA-P Group. (2015). Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. BMJ, 349, g7647. doi: 10.1136/bmj.g7647. Available from: http://www.bmj.com/content/349/bmj.g7647.long.
Umscheid C. A. (2013). A Primer on Performing Systematic Reviews and Meta-analyses. Clinical Infectious Diseases, 57(5), 725-734. doi: 10.1093/cid/cit333. Available from: http://cid.oxfordjournals.org/content/57/5/725.long.
Updated: July 13th, 2017 09:30