Mapping to MeSH (The art of trapping MeSH equivalence from within narrative text)

A tool for identifying Medical Subject Headings (MeSH) Terms found in narrative text is evaluated and discussed. The system's task is to discern unique matches from within MeSH for noun phrases in narrative text. The program consists of a medical morphological reduction routine, coupled with data structures created for the MeSH vocabulary searcher, MicroMeSH. To evaluate this tool, a study was undertaken within which three physicians were asked to review 23 citations from the Annals of Internal Medicine and three paragraphs from a Textbook of Cardiology. They were asked to identify all of the important medical concepts within both the citations and text. Then these same physicians used MicroMeSH, to see which of these medical concepts could be mapped to MeSH. These results were compared to the output of our automated system. Of the concepts which were found to be medical concepts by our panel of experts 89% were identified using MicroMeSH as being represented in MeSH. The automated system was able to translate 90% of those medical concepts to the same MeSH term as identified by MicroMeSH. The remaining 10% of the concepts, which were recognized by the experts and not by the system, were terms where the medical knowledge of the experts allowed them to find matches which had no representation, morphologically or through an Entry Term, in the MeSH vocabulary. The specific algorithms, details of evaluation and potential usefulness of the system are discussed.