OLDMEDLINE Content Continues to Extend Back in Time
I n October 2008, approximately 70,000 citations from the 1948 Current List of Medical Literature (CLML) were added to the OLDMEDLINE citation subset in PubMed®. To search PubMed for all citations originating from the OLDMEDLINE print index conversion project, use jsubsetom.
Mapping the old keywords to current MeSH® is an ongoing project. The majority of citations from the 1949 CLML added to PubMed in December 2007 were mapped during this past year, and the majority of citations from the newly added 1948 CLML have also been mapped. NLM estimates that approximately 93% of the jsubsetom citations have at least one current MeSH Heading (while 78% have been completely mapped) and will, therefore, be retrieved by PubMed searches that incorporate MeSH headings. About 77% of the original main subject headings themselves have been mapped (this has dropped from 89% as more new headings are encountered with each new index that is converted; also, many of the subheadings attached to the original subject headings remain to be mapped).
For additional information about the OLDMEDLINE data project, see: http://www.nlm.nih.gov/databases/databases_oldmedline.html.
Von Braunsberg S. OLDMEDLINE Content Continues to Extend Back in Time. NLM Tech Bull. 2008 Nov-Dec; (365):e5.