1. Literature searching for
systematic reviews
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/

2. Systematic reviews
• “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” (Cochrane
Library)
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
Cochrane Library (2013). About Cochrane Systematic Reviews and Protocols [online]. Available at:
http://www.thecochranelibrary.com/view/0/AboutCochraneSystematicReviews.html [accessed 19/7/2013].

3. Publication bias
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
To avoid publication bias the search must
pick up on:
• All published research:
• In major peer reviewed journals
• In lesser known publications
• Any non-published research
• Non-English language materials

4. Finding Published research
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
Searching for published research is the easy bit …
• Major bibliographic databases e.g. Medline and
Embase
• Specialised databases e.g. PsycINFO for
psychology and psychiatry
• Trials registers
• Hand checking reference lists of relevant articles
• Citation searching – searching for articles that
have cited relevant papers

5. Finding unpublished research
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
Finding unpublished research is not so easy, but
there are some good places to start
• Trials registers – to identify trials currently in
progress
• Conference proceedings
• Dissertations
• Contacting authors / experts
• Searching the websites or repositories of
professional societies, relevant organisations
and academic institutions

6. Resources
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
The University of York Centre for Reviews
and Dissemination provide a guide to
useful resources for systematic review
searches
http://www.york.ac.uk/inst/crd/pdf/Findin
g_studies_for_systematic_reviews.pdf

7. Search strategies
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
• The search needs to be highly sensitive
to ensure nothing is missed
• It’s better to be too broad and exclude
studies later than miss out on something
relevant
• The search strategy needs to be
documented

8. Search strategies
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
• Use PICO to break down your search
strategy into concepts:
• Patient / population
• Intervention
• Comparison
• Outcome
• You don’t need to use all parts of the
PICO if it might restrict your search

9. Search strategies
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
• Identify all possible terms
• Think about synonyms, abbreviations,
acronyms, spelling variants
• Use both free text searching and controlled
vocabularies (e.g. MeSH)
• Look at how relevant papers have been
indexed to identify terms
• Look at search strategies of relevant papers
to identify keywords

10. Search strategies
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
• Use operators to combine your searches:
• OR to combine related terms, synonyms etc.
• AND to combine all your concepts together
• ADJ or NEAR for terms in close proximity
• Search filters can be used in some
databases to identify particular types of
study e.g. randomised controlled trials
www.york.ac.uk/inst/crd/intertasc/

11. Summary
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
When carrying out a literature search for a
systematic review you must:
• Search all relevant databases and other
resources
• Find unpublished material
• Consider all possible terminology
• Ensure that your search is broad,
systematic and comprehensive

12. Further reading
RDF
InformationLiteracy
http://www.library.qmul.ac.uk/
Both Cochrane and the CRD at York produce
comprehensive guides to conducting
systematic reviews
• http://www.york.ac.uk/inst/crd/SysRev/!S
SL!/WebHelp/SysRev3.htm
• http://handbook.cochrane.org/