Use of MeSH in Online Retrieval

In addition to being searchable by MeSH headings, citations are also searchable in PubMed through the use of any word that appears in the title, abstract, or elsewhere in the citation entry. A user does not have to use one or the other, but can use both: either in combination.

If, for example, the searcher has no idea what MeSH term or terms have been used in indexing relevant literature, a useful strategy is to begin with a text word search. Having found a few good citations, then the searcher may look at the MeSH terms used in indexing and identify those that will retrieve further relevant citations. One of the greatest advantages of an online system is the opportunity it affords one to perform a heuristic iterative search in this manner. This is particularly helpful for the occasional searcher or when searching in areas of very rapid change where MeSH may be less developed or indexing less consistent.

The MEDLINE searcher may elect to search using MeSH terms at any particular level of generality or specificity. Using the automatic exploded query retrieves all articles indexed with a given MeSH descriptor as well as all indexed with any more specific descriptors subsumed under it. Thus Pneumoconiosis retrieves articles indexed with that descriptor and also citations indexed to each of the specific pneumoconioses under it, including Asbestosis, Berylliosis, Byssinosis, Caplan's Syndrome, Siderosis, and Silicosis along with, the two more specific descriptors positioned under it, Anthracosilicosis and Silicotuberculosis.

Many more entry terms to MeSH descriptors are available in the MEDLINE database. They consist of variations in the form, word order, or spelling of a descriptor or printed entry term. Trade names of drugs and equipment are usually not printed, but may exist as non-print entry terms. When an entry term is used, the computer automatically substitutes the MeSH descriptor to which the entry term refers.