Medical Subject Headings (MeSH) Dr. Yan Ma

Medical Subject Headings MeSH is designed and used by the National Library of Medicine. It was first based on LCSH, but it is quite different from LCSH now. In the 1950s, MeSH started to develop its own format. MeSH is now has two versions: 1. Index Medicus MeSH for indexing journal articles. 2. Annotated MeSH that is used by indexers and catalogers.

Medical Subject Headings MeSH appears in 3 volumes: 1. Medical Subject Headings--Annotated Alphabetic List. 2. Medical Subject Headings--Tree Structures. 3. Permuted Medical Subject Headings.

Medical Subject Headings 1. MeSH annotated list: contains main headings and topical and form subheadings with notes and cross-references. Subheadings and instruction on their use are listed separately rather than under the main headings with which they may be used.

Medical Subject Headings Pre-explosions pre-stores all the citations that are normally retrieved in an online EXPlode command. Seventy-three MeSH headings requiring excessive computer time to explore in NLMs retrieval system can be searched as pre-explosions. Pre- explosions are from the tree structures. So, they are all narrower terms.

Medical Subject Headings Form, geographic, and language subheadings used in cataloging are listed separately in Appendixes A to C.

Medical Subject Headings 2. MeSh Tree Structures: consists of a categorical arrangement placing headings in relationship to other headings that represent similar areas and concepts. A system of tree numbers (capital letter followed by one or more strings of numbers) is used to reflect the hierarchies.

MeSH Tree Structure: 15 Major Categories: AAnatomy BOrganisms CDiseases DChemical and Drugs EAnalytical, Diagnostic, and Therapeutic Techniques and Equipment F Psychiatry and Psychology

MeSH Tree Structure: 15 Major Categories: GBiological Sciences HPhysical Sciences IAnthropology, Education, Sociology and Social Phenomena JTechnology, Industry, Agriculture KHumanities LInformation Sciences

MeSH Tree Structure: 15 Major Categories: MNamed Groups NHealth Care ZGeographical

MeSH Tree Structure The tree structure provides a classificatory approach to medical subject headings, manifesting the hierarchical structure of the subject headings and providing a logical basis for the cross-references. In online system, the tree numbers, also called descriptor codes, can be used to retrieve related subjects.

Medical Subject Headings 3. Permuted Medical Subject Headings: is a keyword index listing each significant word in the subject heading phrase or cross- reference regardless of its position in the phrase.

Structure of MeSH Headings Structure of Headings: Major descriptors or main headings represent the main topics. Most of the main headings are in the form of single words or phrases.

Structure of MeSH Headings There are other types of main headings such as publication types or citation types. They include such terms as ABSTRACT, BIBLIOGRAPHY, CONGRESS. A publication-types main heading characterizes what a publication is rather than what it is about.

Structure of MeSH Headings Some headings are only for indexing purposes. For example, HUMAN (check tag only, CATALOG: do not use. for indexers only), ANIMAL is another example.

Structure of MeSH Headings Sometimes a main heading is coded NON- MESH. This means that it is not used in indexing or cataloging but serves to group headings in the MeSH Tree Structures.

MeSH Subheadings It is called Subheadings, NOT Subdivisions in LCSH

MeSH Subheadings There are four types of subheadings: topical, form, geographic, and language. The latter three are used only in cataloging and not in indexing.

MeSH Cross-References There are two categories of references in MeSH: see reference and related concept indicators. Example: vidine see choline

MeSH Cross-References Reciprocal entries are indicated by the symbol X. choline x vidine

MeSH Cross-References There are 2 types of related concept indicators: see related and consider also. The see related references are used to indicate the presence of other headings that relate to the topic conceptually. CHILD DAY CARE CENTERS see related NURSERIES

MeSH Cross-References Reciprocals are printed under the related headings, indicated by the symbol X NURSERIES XR CHILD DAY CARE CENTER

MeSH Cross-References The consider also reference was instituted in It indicates the presence of the other headings that relate to the topic linguistically. They are primarily used with anatomic headings. A consider also reference refers to groups of headings beginning with a common word stem.

MeSH Cross-References HEART consider also at CARDI- AND MYOCARDI-

Assigning MeSH Headings If the work contains more than one concept, catalogers may apply one or more of the three following methods: 1. using two or more main headings. 2. using a pre-coordinated main heading. 3. using a main heading and a subheading, including topical, geographic, form, or language subheading.

Assigning MeSH Headings If a publication deals with 2 or more subjects that are subordinate to a broad heading, up to 3 separate and specific headings are assigned.

Assigning MeSH Headings If more than 3 subjects are involved, the broad heading encompassing the individual specific topics in the tree structure is assigned. If the specific subjects are not within the tree, as many specific headings as necessary are assigned.

Assigning MeSH Headings For example: a book that deals with aloe, coca, ginseng, mustard as medicine. The broad heading PLANTS, MEDICINAL is assigned. PLANT, MEDICINALB6.560 AloeB CocaB GinsengB MustardB

Assigning MeSH Subheadings A main heading may be divided by topical, geographic, form, and or language subheadings.

Assigning MeSH Subheadings Topical: No more than 3 topical subheadings are assigned under a given main heading. When more than 3 topical subheadings are applicable, the main heading is assigned without topical subheading.

Assigning MeSH Subheadings Geographic: There is a list of geographic locations in Appendix B. Geographic subheadings are used only when the usage is indicated under the main heading in the list specify geog or CATALOG: /geog/form.

Assigning MeSH Subheadings Unlike LCSH, geographic subheadings always appear directly in MeSH. COMMUNITY HEALTH SERVICES--BOSTON (MeSH) COMMUNITY HEALTH SERVICES-- MASSACHUSETTS--BOSTON. (LCSH)

Assigning MeSH Subheadings Only 1 geographic subheading is allowed. If your need 2, use 2 separate headings. If more than 3 geographic areas are involved, and all of which are within a larger area, the subheading for the larger area is used. Dental Care--Midwestern United States.

Assigning MeSH Subheadings There are exceptions: page I-149 epidemiology, prevention & control Even a main heading is not annotated for geographic subheading, but when it is combined with certain topical headings, such as those listed above, the subject may have a geographic emphasis.

Assigning MeSH Subheadings Examples: Kidney Diseases--epidemiology--New York City. Neoplasms--prevention & control--United States.

Assigning MeSH Subheadings There are 3 form headings that may imply geographic consideration: directories legislation statistics

Assigning MeSH Subheadings Form Subheadings: Form subheadings are used to indicate the form of the overall publication and are generally assigned to all subject headings for a particular publication. If more than 2 form subheadings which are not pre- coordinated in the list apply to a particular publication, the main heading is repeated with individual form subheadings.

Assigning MeSH Subheadings Examples: Dental Care--United States--directories Dental Care--United States--handbooks

Assigning MeSH Subheadings Language Subheadings: Appendix C is a list of languages. When more than 1 type of subheading is applied to a main heading, the citation order of subheadings: main headingtopicalgeographicform-- language subheadings

Assigning MeSH Subheadings Few headings contain 4 subheadings since language subheadings are extremely limited in application.

Assigning MeSH Subheadings Topical Subheadings Allowable Categories The tree number indicated in the main heading serves a category purpose when assigning a subheading.

Comparisons of LCSH, Sears, and MeSH LCSH is designed and used for LC and other large libraries in US. Sears is used for small and medium size libraries. MeSH is used for medical materials in the US and other countries. That is especially true with Medline.

Comparisons of LCSH, Sears, and MeSH Syntax of headings: similar MeSH has tree numbers, notes for cataloging. Both LCSH and Sears use BT, RT, NT, etc. MeSH uses X, XR, See related, also consider.

Comparisons of LCSH, Sears, and MeSH Subdivision: LSCH: subdivisions are listed or listed in the free- floating subdivision list There are pattern headings.

Comparisons of LCSH, Sears, and MeSH Subdivision: Sears: Key headings or Headings to be Added by the Cataloger There is a list of Commonly Used Subdivisions for the Cataloger to add.

Comparisons of LCSH, Sears, and MeSH Topical subdivision/subheadings: LCSH and Sears: in the list MeSH: Use them according to the allowable categories.

Comparisons of LCSH, Sears, and MeSH Form subdivision/subheadings: LCSH: there is a free-floating subdivision list Format subdivisions are indicated in the free-floating subdivision index. MeSH: there is a list of form subheadings such as CD-ROMs, videocassette, ect.

Comparisons of LCSH, Sears, and MeSH Geographic subdivision/subheading: LSCH: by larger geographic region or jurisdiction except US. Britain, and Canada. MeSH: use the most specific if instructed.

Comparisons of LCSH, Sears, and MeSH Language subheading: In MeSH, there is a category of language as subheading.

Comparisons of LCSH, Sears, and MeSH MARC Tagging: is for LCSH is for MeSH is for Sears