Understanding MeSH for Literature Searches

To the Editor. —In their recent article, Drs Lowe and Barnett1give a comprehensive and instructive overview of how to use the National Library of Medicine's Medical Subject Headings (MeSH) vocabulary when searching the MEDLINE database. The authors believe that successful MEDLINE searches require the use and knowledge of MeSH. This is, of course, true. On the other hand, they mention the problem with "free-text" searching for words in titles or abstracts, stating that this method is often an important reason why MEDLINE searches fail. In my experience, MeSH alone is not sufficient when creating powerful and comprehensive MEDLINE searches. I believe that both the MeSH vocabulary and free-text searching must be used. The MeSH vocabulary is an excellent tool, but the depth and quality of indexing vary, and there is no doubt that MEDLINE—as well as most databases—suffers from incomplete indexing.2 A basic principle in indexing ought