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Health Equity Research

Understanding and using controlled vocabulary to search for specific populations

To be able to find the literature you need it's important to understand how databases work. Indexers read articles and add subject headings (or controlled vocabulary) to articles to help you find them, as well as to describe what articles are about. In PubMed, the subject headings are called MeSH. What is MeSH? In EMBASE, subject headings are called Emtree. What is Emtree?

When you're searching, keep these tips in mind:

  • It's not always obvious how articles are indexed. Look at the indexing for the most relevant articles for your project - you should start to see patterns
  • Controlled vocabulary cannot replicate the nuance inherent in language - you may need to combine terms, and use subject headings plus keywords to find what you need
  • Make sure you read the definition (or scope note) before using a specific subject heading - the database may define a word differently than you do
  • Language can change rapidly, but databases don't keep up as quickly. (MeSH is updated once a year.) Check to see what date the subject heading you are using was introduced - if it's fairly new, you'll have to use additional terms to find older articles. For example, the term Sexual and Gender Minorities was introduced in 2018:The MeSH term Sexual and Gender Minorities is from 2018
  • Also check the list of entry terms on a MeSH term - if the term you use isn't on the list, it won't map to the MeSH term. For example, if you were to type LGBTQIA into PubMed, it won't map to the Sexual and Gender Minorities MeSH heading because it is not an entry term. We recommend using keywords and subject headings when searching.

Get help

Remember you can always ask a librarian or contact the specific liaison for your school if you need search assistance.