Last month we introduced you to the changes in the 2002 edition of the Medical Subject Headings (From Herbs to Angiosperms -New 2002 MeSH). This month we continue the discussion and highlight the implications for database searching.Mesh 2002
Every year the National Library of Medicine updates their controlled vocabulary, Medical Subject Headings (MeSH), to keep indexing terms up to date and increase precision for areas where current research calls for a more nuanced vocabulary. This means you should verify that your search strategies are still current and effective. The additions, replacements and deletions have been announced for 2002 and the statistics show that it's been a busy year:
| | 2000 | 2001 | 2002 |
|---|
| Descriptors added | 552 | 184 | 847 |
| Descriptors replaced | 130 | 4 | 185 |
| Descriptors deleted | 16 | 10 | 47 |
Two years ago Tom Ipri, writing in Jeffline Forum, pointed out some changes for MeSH 2000 including removal of possessives (e.g., Adie's Syndrome became Adie Syndrome) and preference for plurals (e.g., Apraxia became Apraxias). These trends continue in the 2002 revisions with, for example, Turner's Syndrome becoming Turner Syndrome, and the pluralization of fish species (e.g. Hagfish becomes Hagfishes).
The largest category of additions comes under Plants with approximately 350 descriptors added. This shows an emphasis on herbal medicine, whose descriptor changes from Medicine, Herbal to Phytotherapy to include other sources of botanical medicines besides herbals. Most plants are added under their more scientifically precise Latin names with a few exceptions such as Blueberry Plant, Huckleberry Plant and Shallot. But Peanuts changes to Arachis hypogaea, Grasses to Poaceae, Herbs to Angiosperms and Ginseng to Panax. One change in the other direction is Viscum, which becomes Mistletoe.
There is also an emphasis on Complementary Therapies, formerly Alternative Medicine. They restructured this category bringing together existing terms, such as acupuncture, with new terms, such as Laughter Therapy.
Many additions were made in the field of Ethics and Bioethics, such as Ethics Committees and Moral Obligations, to prepare for the addition of citations formerly in the BIOETHICSLINE database (discontinued in December 2000) into PubMed. NLM made these changes through a joint effort with the Kennedy Institute of Ethics.
Current events-driven additions include Foot-and-mouth Disease Virus; Food, Genetically modified; and Drug Resistance, viral.
The indexing of virus names was updated to conform to the 7th Report of the International Committee on Taxonomy of Viruses (ICTV). Many new virus names have been added to MeSH and older terminology has been changed. One of the most significant changes is with name revisions for Retrovirus types. For example, Retroviruses Type C, Avian is now indexed as Alpharetrovirus. Additionally, some viruses previously indexed by an acronym are being replaced with the full virus name, such as STLV being replaced with Simian T-lymphotropic virus 1.
All this means it's important to review your search strategies. Use the 2002 MeSH Browser to verify that your search terms are still valid and read the scope notes to make sure the terms gives the coverage you expect.
NLM will start indexing with the new vocabulary after they finish their year-end processing activities. Changes will appear in PubMed first with the changes appearing in OVID soon after. Ovid estimates that existing citations will be updated with the new terms and should be available in Medline by the end of January or early February.
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