MEDLINE Indexing Online Training Course
Indexing for MEDLINE
Introduction: What do we index?
MEDLINE indexers describe the content of biomedical articles by assigning subject terms to them. These subject terms are selected from the controlled vocabulary, Medical Subject Headings (MeSH). The MeSH terms assigned to an article appear on the bibliographic citation in PUBMED. They can be used in PUBMED searches and retrieval .
The MeSH controlled vocabulary, developed at NLM, contains over 27,000 terms covering life sciences, medicine, as well as many other areas. MeSH vocabulary reflects the progress in biomedical sciences. Every year, several hundred new terms are added to the MeSH vocabulary, and some existing terms are modified. In addition to the MeSH descriptors, MEDLINE indexers also use 80 topical subheadings or qualifiers.
A typical MeSH record (for MYOCARDIAL INFARCTION) is displayed below.
A detailed explanation of MeSH records will follow later in this course.
It is important to understand that ONLY terms listed in the MeSH vocabulary can be used for indexing. For example, an article about myocardial infarction is indexed with a single MeSH term MYOCARDIAL INFARCTION. However, an article about Mauriac syndrome cannot be indexed with the exact term, because Mauriac syndrome is not listed in the MeSH vocabulary. The indexer would need to find the closest MeSH term(s), which best describe this syndrome. It may be necessary to consult the Dorland’s Medical Dictionary or another source.