Author keywords in biomedical journal articles.

As an information retrieval system, PubMed(®) aims at providing efficient access to documents cited in MEDLINE(®). For this purpose, it relies on matching representations of documents, as provided by authors and indexers to user queries. In this paper, we describe the growth of author keywords in biomedical journal articles and present a comparative study of author keywords and MeSH(®) indexing terms assigned by MEDLINE indexers to PubMed Central Open Access articles. A similarity metric is used to assess automatically the relatedness between pairs of author keywords and indexing terms. A set of 300 pairs is manually reviewed to evaluate the metric and characterize the relationships between author keywords and indexing terms. Results show that author keywords are increasingly available in biomedical articles and that over 60% of author keywords can be linked to a closely related indexing term. Finally, we discuss the potential impact of this work on indexing and terminology development.