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MeSH Update. A presentation for the Authority Control Interest Group ALA Midwinter Meeting, Boston, Mass. January 17, 2010 Diane Boehr Head of Cataloging, National Library of Medicine, NIH, DHHS boehrd@mail.nlm.nih.gov. Introduction. MeSH: Medical Subject Headings
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MeSH Update A presentation for the Authority Control Interest Group ALA Midwinter Meeting, Boston, Mass. January 17, 2010 Diane Boehr Head of Cataloging, National Library of Medicine, NIH, DHHS boehrd@mail.nlm.nih.gov
Introduction • MeSH: Medical Subject Headings • A thesaurus of medical terminology developed and maintained by the National Library of Medicine • Descriptors are arranged both alphabetically and hierarchically (trees) • Used at NLM for indexing in medical journals in MEDLINE/PubMed and for cataloging of books, serials, AVs, etc.
MeSH Record Types • Descriptors (Main Headings) • Categories A-N of the MeSH trees • Publication Characteristics (Publication Types) • Category V of MeSH tree • Geographics • Category Z of the MeSH tree • Qualifiers (subheadings) • All updated on an annual basis
MeSH Record Types • Supplementary Concept Records (formerly Supplementary Chemical Records) • Used by indexing for specific substance names, such as chemicals and drugs • Not used in cataloging • No tree numbers—each is mapped to one or more Descriptors • Updated weekly
MeSH • Available as an online tool through the MeSH browser http://www.nlm.nih.gov/mesh/MBrowser.html • Also available for downloading • XML format (weekly) • ASCII format (weekly) • MARC 21 format (monthly)
MeSH Statistics • Contains 25,588 Descriptors and over 160,000 entry terms • 83 Qualifiers • 186,686 Supplementary Concept Records (SCRs)
MeSH-MARC files • Descriptor terms: 150 field • Geographic terms: 151 field • Publication characteristics: 155 field • Subheadings: 180 field, but MeSH-MARC records are also created for every valid head/subheading combination: 150 $a $x
Faceted Subject Analysis • The MARC structure of the distributed records reflects the way NLM applies the subject headings in its catalog • NLM does not use the full 650 subject strings permitted in MARC • Instead of 650 $z, NLM uses 651 • Instead of 650 $v, NLM uses 655 • NLM uses 650 $x only for topical subheadings • Main descriptors are used for temporal information • Language information is in 008 and 041 only
Faceted Subject Analysis • Adopted in 1998 when the library implemented the Voyager ILS • Followed indexing practice • Allowed for better retrieval in a federated search of NLM databases • Better semantic interoperability in the online environment
Distribution of Bibliographic Records • In its distribution of MARC bib records, NLM programmatically reattaches the 651 and 655 fields as $z and $v respectively to the 650 fields in the records
Example • In LocatorPlus database • 650 12 $a Health Maintenance Organizations $x history • 650 22 $a History, 20th Century • 651 2 $a United States • 655 2 $a Interview • 655 2 $a Personal Narratives • MARC distributed record • 650 12 $a Health Maintenance Organizations $x history $z United States $v Interview • 650 12 $a Health Maintenance Organizations $x history $z United States $v Personal Narratives • 650 22 $a History, 20th Century $z United States $v Interview • 650 22 $a History, 20th Century $z United States $v Personal Narratives
Example • In LocatorPlus • 650 12 $a Drug Interactions • 650 12 $a Pharmacokinetics • 650 12 $a Pregnancy $9n • 650 22 $a Breast Feeding $9n • 655 2 $a Handbooks • MARC 21 distribution • 650 12 $a Drug Interactions $v Handbooks • 650 12 $a Pharmacokinetics $v Handbooks • 650 12 $a Pregnancy • 650 22 $a Breast Feeding
Overview of 2010 MeSH Changes • Added 422 Descriptors • 52 Descriptor terms replaced with more up-to-date/accurate terminology • 20 Descriptors were deleted
Further Information • For complete instructions on how to create a subject string from a LocatorPlus record: http://www.nlm.nih.gov/mesh/catpractices.html#CreatingTraditional • For complete instructions on how to create a faceted subject display from an OCLC record: http://www.nlm.nih.gov/tsd/cataloging/unstringmesh.html
Major Tree Revisions • Category B (Organisms Tree) was reorganized in a major fashion to reflect current thinking • 20th century classification emphasized modes of nutrition and locomotion • 21st century classification is based on ultrastructure, biochemistry and genetics • Protozoa was deleted as an outmoded phylogenetic concept
Major Tree Revisions • Organisms formerly treed under Protozoa are now chiefly treed under Eukaryota and are no longer treed under Animals • However, terms such as Protozoan Infections, Protozoan Genes, and Protozoan Proteins were retained
Rare Diseases • Collaborative effort between NLM and the NIH Office of Rare Diseases and Research (ORDR) to merge the list of rare disease terms maintained by ORDR into the MeSH vocabulary http://rarediseases.info.nih.gov/RareDiseaseList.aspx • 10,379 terms have been reviewed • 440 identified as already in MeSH • 274 were added in 2010 • 372 will be added in 2011 • The rest will become a new category of Supplementary Concept records in 2011
2010 Changes • Influenza A Virus, H1N1 Subtype was adjusted • Entry terms added for H1N1 Virus and Swine-Origin Influenza A H1N1 Virus • No entry term for "swine-flu" because of the ambiguity of this term • Catalogers and indexers coordinate this with Influenza, Human as needed
Annual Updating at NLM • Both the PubMed/Medline and LocatorPlus/NLM Catalog files are updated annually after the new MeSH files are issued • Descriptors in existing records are changed to reflect the new vocabulary, but reindexing does not occur • In some cases, when a concept has split into 2 new headings we may need to do special processing or manual examination of records to assign the new headings correctly
Local Catalog Decisions • All bib records that have been changed are redistributed to our subscribers, including OCLC—so a library may get these changes if they subscribe to an updating service • Locally created records in your catalog will not automatically get updated, nor will OCLC records using MeSH created by other libraries
Annual Updating • Indexing uses the MeSH Identifier number to find and replace records for year end processing • Library catalogs generally do not carry the MeSH identifier in bibliographic records, so we must rely on the character strings to identify needed changes
Updating Voyager • Each year Cataloging takes the list of changed and deleted headings supplied by MeSH and loads them into our test Voyager database • This generates a global queue change list of old and new headings and the number of bib records impacted for each heading. Replaced headings with no associated bib records are ignored
Updating Voyager • We create Excel spreadsheets from the global change list which are then manually reviewed to make sure the old and new headings are correct • Because Voyager ignores punctuation, when the only change to the heading is in punctuation, we must find these manually • E.g. Biofeedback (Psychology) changes to Biofeedback, Psychology
Updating Voyager • The case of "as Topic headings“ • Portraits vs. Portraits as Topic • Bibliography vs. Bibliography as Topic • Do you add “as Topic” to all your 650’s or do you flip your 650’s to 655?
Expected future directions for 2011-12 • More work on rare diseases • Examination of disaster headings • In 2012 the 5th ed. of the Diagnostic and statistical manual of mental disorders (DSM-V) will be released
Acknowledgments • Thanks to Jacque-Lynn Schulman, Senior Technical Information Specialist, MeSH Section and Sharon Willis, Senior Cataloging Specialist, Cataloging Section for their assistance in preparing this presentation