Medical indexing outside the National Library of Medicine.

The National Library of Medicine's (NLM's) success with Web offerings of MEDLINE has brought Medical Subject Headings (MeSH) indexing, once familiar mostly to librarians and researchers, to an entire community of students, teachers, researchers, and practitioners in the life sciences and medicine as well as to the general public. The emergence of MeSH as the accepted standard, however, creates dilemmas for indexers outside NLM. Conflicts between MeSH and subject terms suggested in text may be ignored or resolved with cross-references in indexing textbooks and monographs, but indexers dealing with periodical literature consisting of articles from many different authors depart from MeSH only advisedly, especially when indexing for a readership of frequent MEDLINE users. Professional researchers may regard cross-referencing to appropriate MeSH terms as a minimum functionality in any system for searching the medical literature, their expectations set by their experience with popular MEDLINE interfaces that automatically map keywords to MeSH. In a recent review of reference-management software in JAMA, for example, Satya-Murti, citing the search of MEDLINE as “an irreducible step” in medical research, faults the products under consideration for the lack of MeSH cross-referencing, concluding that “concepts such as continuous glucose monitoring or stool test may produce variable and irrelevant results. To aid in specificity, mapping a free-text term to MeSH vocabulary is critical” [1].