How to Search for Systematic Reviews
To find systematic reviews, use the systematic review filter or subset in PubMed together with your topic terms, then check the Cochrane Library, PROSPERO for registered and ongoing reviews, and other evidence sources. Then judge each review for currency and methods before relying on it.
Where to search
- PubMed: a systematic review filter or subset; combine with topic terms.
- Cochrane Database of Systematic Reviews: Cochrane reviews of interventions.
- PROSPERO: registered protocols, including ongoing reviews not yet published.
- Other evidence sources: health-technology assessment and guideline databases.
- Reference lists of guidelines and key papers.
Judge the review
| Question | Why it matters |
|---|---|
| Is the question like mine? | Populations and outcomes may differ |
| When was the search done? | Evidence may be out of date |
| Was the search comprehensive and reproducible? | Missed studies bias results |
| Was risk of bias assessed? | Conclusions depend on study quality |
| Were methods pre-registered? | Reduces selective reporting |
| Did authors follow PRISMA? | Completeness of reporting |
Illustrative example
Invented for teaching. A search finds three reviews on exercise for knee osteoarthritis. One searched until 2015, one pooled only small trials, and one is a registered, recent review with risk-of-bias assessment. The student uses the third as her main source and notes its limits.
Using reviews without over-trusting them
A review can still contain errors or become outdated when new trials appear. Check the date of the last search, and run a brief update search from that date for new primary studies. If two reviews on the same question reach different conclusions, compare their eligibility criteria, search dates and methods to understand why before deciding which to rely on.
Common pitfalls
- Assuming every paper titled "systematic review" followed systematic methods.
- Missing an ongoing review that already covers your question.
Key takeaways
- Search several sources including PROSPERO.
- Appraise currency and methods.
- Use reviews to locate primary studies and to identify evidence gaps.
References and further reading
- National Library of Medicine. PubMed User Guide. Link
- PROSPERO: International prospective register of systematic reviews (Centre for Reviews and Dissemination, University of York). Link
- Higgins JPT, Thomas J, Chandler J, et al., editors. Cochrane Handbook for Systematic Reviews of Interventions. Cochrane. Link
- Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. doi:10.1136/bmj.n71
Related reading
This page is general educational information about research methods. It is not medical, legal or regulatory advice; follow your institution's ethics board and your target journal's instructions.