Understanding MeSH Terms

What are MeSH Terms?

MeSH (Medical Subject Headings) is a controlled vocabulary used to index articles in PubMed/MEDLINE. MeSH can retrieve indexed articles under standardized concepts regardless of the words authors used, but keyword searches are also needed for records that are not yet indexed or use different terminology.

Why Use MeSH?

  • Standardizes terminology: 'heart attack' and 'myocardial infarction' both indexed as 'Myocardial Infarction'
  • Captures spelling variations: 'pediatric' vs 'paediatric'
  • Includes related concepts automatically using tree structure
  • Finds relevant articles even when exact keywords aren't in title/abstract
  • Combine with text-word searches when broad coverage is needed

MeSH Tree Structure

MeSH terms are organized hierarchically from broad to specific. Understanding this helps you choose the right level of specificity.

  • Example hierarchy: Mental Disorders → Mood Disorders → Depressive Disorder → Depressive Disorder, Major
  • Searching a broader term automatically includes narrower terms (called 'explosion')
  • You can turn off explosion to search only that specific term

Finding MeSH Terms

  1. 1Use PubMed's MeSH Database (https://www.ncbi.nlm.nih.gov/mesh)
  2. 2Enter your keyword (e.g., 'diabetes')
  3. 3Review suggested MeSH terms and definitions
  4. 4Check the tree structure to see related terms
  5. 5Note subheadings (qualifiers) if applicable
  6. 6Add selected MeSH terms to your search builder

MeSH Subheadings

Subheadings (also called qualifiers) narrow MeSH terms to specific aspects.

  • /therapy - treatment aspects
  • /diagnosis - diagnostic methods
  • /epidemiology - occurrence and distribution
  • /prevention and control - preventive measures
  • /etiology - causes and risk factors
  • Example: 'Diabetes Mellitus/therapy' finds only diabetes treatment articles

When to Use Subheadings

  • Intervention reviews: /therapy, /prevention and control
  • Diagnostic reviews: /diagnosis
  • Etiology/risk factor reviews: /etiology, /epidemiology
  • Increases precision but may reduce sensitivity

Combining MeSH and Keywords

Best practice is to use both MeSH terms and text words (keywords) in your search strategy.

  • MeSH terms catch articles indexed with that concept
  • Keywords catch recently added articles not yet indexed
  • Keywords catch terminology not well-represented in MeSH
  • Combine with OR: ('Diabetes Mellitus'[MeSH] OR diabetes[TIAB])
  • Provides maximum sensitivity

MeSH Major Topic [MAJR]

Major topics indicate the main focus of an article (marked with * in MEDLINE indexing).

  • Use [MAJR] to find articles primarily about that topic
  • Example: 'Diabetes Mellitus'[MAJR] vs 'Diabetes Mellitus'[MeSH]
  • Increases precision but decreases sensitivity
  • Consider for focused reviews or when precision is critical

Common MeSH Search Examples

Intervention Review

('Diabetes Mellitus, Type 2'[MeSH] OR 'type 2 diabetes'[TIAB]) AND ('Exercise'[MeSH] OR exercise[TIAB] OR 'physical activity'[TIAB])

With Study Design Filter

('Depression'[MeSH] OR depression[TIAB]) AND ('Cognitive Behavioral Therapy'[MeSH] OR 'cognitive behavioral therapy'[TIAB]) AND ('Randomized Controlled Trial'[Publication Type] OR 'randomized controlled trial'[TIAB])

MeSH Limitations

  • New concepts may not have MeSH terms yet
  • Recently published articles not yet indexed (MEDLINE indexing takes months)
  • Very specific topics may lack precise MeSH terms
  • MeSH is specific to PubMed/MEDLINE (other databases use different vocabularies)
  • Always combine MeSH with keyword searches for comprehensive coverage

Other Controlled Vocabularies

Other databases use similar controlled vocabularies:

  • Embase: Emtree terms (more extensive drug and European coverage)
  • CINAHL: CINAHL Subject Headings (nursing and allied health focus)
  • PsycINFO: APA Thesaurus (psychology terminology)
  • Each requires separate term lookup and translation

Scholara automatically suggests relevant MeSH terms based on your PICO framework and helps translate searches across different databases. For comprehensive systematic reviews, always use both controlled vocabulary (MeSH/Emtree) and text word searching.

References