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PubMed Searching

Tips for searching NLM PubMed's free database

Keywords and MeSH

Searching with MeSH makes your search more relevant than searching with keywords (aka "All Fields" in PubMed) alone. However, there is a delay in getting MeSH terms added to articles, so if you only search using MeSH you will miss the latest research.

Also, there's not a MeSH term for every concept. Sometimes keywords are the most direct way to find what you need. 

For a comprehensive search, ensure that you use a combination of MeSH and keywords.

Keyword search tools:



The basics of PICO

This video describing PICO was developed for the CINHL nursing database, but the concepts also apply to PubMed. Framing your question in PICO format can help you identify key components of your search.

Differences between PubMed and Ovid MEDLINE

PubMed and Ovid MEDLINE have nearly 100% of the same content, but how you search them is quite different. You can learn more about searching Ovid MEDLINE from UBC Library's tutorials.

Ovid Medline allows you to:

  • insert a line into your search
  • delete a search line, without clearing the entire search
  • use adj operator for proximity searches - this finds words near each other, and has no equivalent in PubMed
  • discover relevant MeSH terms more easily (PubMed's mapping functionality is often more limited)
  • does not automatically search for narrower MeSH terms (aka "explode") like PubMed does 

Additionally, drug terms are handled quite differently in PubMed and Ovid MEDLINE. PubMed makes more use of Pharmacological Action terms. For more details on drug searching in PubMed, see the guides below.