Journal articles are indexed for MEDLINE using NLM's controlled vocabulary, MeSH (Medical Subject Headings). Citations are created by the National Library of Medicine, International MEDLARS partners, and cooperating professional organizations.
MEDLINE has worldwide coverage, but 88% of the citations in current MEDLINE are to English-language sources and 76% have English abstracts. In 2001, NLM reconfigured MEDLINE to contain only citations to journal articles (not books or book chapters), and to contain all journal article citations produced by NLM. MEDLINE now incorporates article citations that were previously part of separate databases, including AIDSLINE, BIOETHICSLINE, and HealthSTAR (Health Services Technology, Administration, and Research). Corresponds in part to the following print indexes: Index Medicus, Index to Dental Literature, and International Nursing.
NLM provides free access to MEDLINE through PubMed. In addition to providing the PubMed search interface, the NLM licenses the content of MEDLINE to commercial database vendors. For a fee, these vendors will provide the content of the database through an interface with different search features and capabilities than PubMed. Two such vendors are EBSCO and ISI which are the vendors used by the University of Texas Libraries.