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MEDLINE search tips: Narrow or Broaden

Tips for searching and creating a search strategy in MEDLINE

How to Narrow a Search

If your search retrieves too many articles, consider the following techniques to get less results.

  • Limit to the main theme of the article by using Focus on main subject heading(s)
  • Select subheadings to limit to a particular aspect of your topic (e.g. therapeutic use, complications)
  • Apply limits such as age groups, clinical queries, or publication types
  • Add another concept to your search, then combine it with your other terms using "and"
  • Try taking out keywords which may be retrieving too much



How to Broaden a Search

If your search retrieves few or no citations, consider the following techniques to broaden your search:

  • Use the Explode feature to include more specific terms e.g. exploding Fractures, Bone includes Spinal Fractures, Tibial Fractures, etc, (Note that Explode is the default in PubMed)
  • Think of additional synonyms or related terms, then combine them with "or"
  • Find a relevant citation and look at the MeSH subject headings for ideas for subject headings to use
  • Remove limits
  • Remove subheadings
  • Use keywords in addition to MeSH headings, combined with "or"
  • When keyword searching, try truncating the search term with * e.g. child* retrieves children, childhood, child

Subject Guide