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USF School of Nursing: Wegner Services


PubMed is a free resource maintained by the U.S. National Library of Medicine (NLM) and the National Center for Biotechnology Information (NCBI).  It contains over 34 million citations from resources such as MEDLINE, biomedical and life science journals, PubMed Central (PMC), and online books from Bookshelf.  PubMed's citations are primarily in disciplines which stem from the biomedicine and health fields, and related disciplines such as life sciences, behavioral sciences, chemical sciences, and bioengineering.



Although it is a free resource, you will want to access PubMed through the Wegner Health Sciences Library's website in order to be connected to Wegner's subscriptions and holdings.  This will allow you faster access to the full-text or the ability to quickly submit an Interlibrary Loan (ILL).

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Controlled Vocabulary & Keywords

Controlled Vocabulary: Medical Subject Headings (MeSH)

Controlled Vocabulary provides a consistent, precise way to retrieve information when different words are used for the same concept, or when the same language is used for different concepts. PubMed's controlled vocabulary is called Medical Subject Headings (MeSH). MeSH terms are organized in a hierarchy and are used for indexing, cataloging, and searching the information found in PubMed.  MeSH terms are found in the MeSH database and account for variations in language, acronyms, plurals, and spelling (e.g., British vs. American English).



Keywords are all the ways to say the same thing and are valuable when there is no controlled vocabular for your search term.  Keywords also catch newer articles that have not yet been, or will not be, indexed with controlled vocabulary. Terms used as keywords will be searched for in the title, abstract, or other text field in the citation record.  Keywords can be:

  • synonyms (Acetaminophen/Tylenol; unit/ward)
  • acronyms (ECMO, CAUTI)
  • free text
  • natural language
  • user-selected terms
  • professional lingo
  • alternate spellings (healthcare/health care; pediatric/paediatric)
  • and more... 



Use controlled vocabulary AND keywords TOGETHER!

Phrases, Truncation, & Field Tags


If you have a phrase, it is recommended to search it within quotation marks ("), otherwise the phrase could be split and the terms searched separately, e.g., "kidney allograft".



Truncation allows you to search for multiple ending variations for a term.  To use truncation in your search, use an asterisk (*) following the term or phrase you want truncated.


vaccin* will search vaccine, vaccines, vaccinate, vaccinates, vaccinated, vaccination, vaccinations, vaccinator, etc.

"iron deficien*" will search "iron deficiency", "iron deficiencies", "iron deficient"

Rules for truncation in PubMed:

  • You must have at least four characters before you can truncate
    • e.g., if you are searching on "mobile apps", you can only use truncation in the following way: "mobile app" OR "mobile apps" OR "mobile appl*"
  • The truncation can only come at the end of a word
    • e.g., if we wanted to search for unvaccinated information as well, we would have to do the following unvaccin*
  • If truncating a phrase, the truncation can only come at the end of the last word
    • e.g., "cheerleading injur*" OR "cheer-leading injur*" OR "cheer injur*"


Field Tags

Field Tags are used with keywords and act like a command that tells the database where to search for the keywords. In PubMed, type your term/phrase and then follow it with the field tag in brackets.  You can find a list of PubMed's field tags in their help guide.  Here are some commonly used field tags in PubMed:

  • [tiab] = title/abstract
    • "cryptogenic organizing pneumonia"[tiab] will only search for that phrase in the title or abstract.
  • [tw] = text word
    • "kawasaki disease"[tw] will search for that phrase in the title, abstract, other abstract, MeSH terms, MeSH Subheadings, Publication Types, Substance Names, Personal Name as Subject, Corporate Author, Secondary Source, Comment/Correction Notes, and Other Terms.
  • [au] = author
    • "sakpal sv"[au] will search for papers authored by Dr. Sujit Sakpal.
  •  [ta] = journal
    • "chest"[ta] will search for articles in the journal, Chest.
  • [ad] = affiliation
    • "University of South Dakota"[ad] will search for articles where an author, corporate author, or investigator has an affiliation with the University of South Dakota.

Boolean Operators

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Boolean operators are used to combine all of your terms together. Boolean operators must be in ALL CAPS in order to be properly recognized by the database. PubMed recognizes three Boolean operators:


OR will broaden your search. Use OR between like terms. "intensive care unit*"[tw] OR "critical care unit*"[tw] OR icu[tw]

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AND will narrow your search.  Use AND between different terms. "Intensive care unit*"[tw] AND "compassion fatigue"[tw]

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NOT will exclude terms from your search. Please consult with a librarian before using NOT in a search as you may be excluding vital references.  adult[tw] NOT child[tw]

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