1

A look at PubMed Indexing:

VGH Robert Ho Research Centre, Journal Club

Dean Giustini | UBC Biomedical Branch Librarian | June 20th 2012A talk for researchers at the RHNH Research Centre

Vancouver Canada

By the end of this session, you will be able to:

Describe the types of content in PubMed/MEDLINE Explain what medical subject headings (MeSH) are Discuss the pros / cons of indexing with MeSH How indexing relates to precision, recall, specificity,

sensitivity

… finding authoritative medical evidencein the biomedical literature

Objectives

3

What is Medline?• What time period does it

cover?• How is it organized?• Why is it important?

MEDLINE is a database of citations to the medical literature

5,600 journals indexed from 1966 to present Journals approved by a review committee

NLM indexers use Medical Subject Headings (MESH) to index 50,000 articles a month

In 2012, MEDLINE has 22 million citations back to mid-1940s

High % of English-language items / all have English abstracts

4

What is Medline?

Literature Selection & Technical Review Committee (LSTRC)

LSTRC is made up of medical experts & librarians Examines hundreds of medical titles yearly Selects 20-25% of reviewed titles Arranges for indexing, XML, NLM loading Done by NLM librarians in Bethesda MD

5

Journal acceptance in MEDLINE

• Access, preservation issues• Indexing should describe & collocate• XML tags for web presentation• Preservation components, PubMedCentral• OLDMEDLINE currently on hiatus

http://www.nlm.nih.gov/bsd/policy/ejournals.html

MEDLINE Indexing Policy

PubMed as of 2012

http://www.pubmed.gov/

7

A MEDLINE RECORD:

Journal name Article title Authors/1st author info Abstracts Language PMID (indexed?) Publication types Medical Subject

Headings Major & minor topics

Subheadings Substances

8

FACTs:

• MeSH (Medical Subject Headings) = Medline’s controlled vocabulary

• Describe journal content

• Aid in informational retrieval

• Indexers assign most specific terms

9

= major descriptors get an *asterisk

Subheadings coordinate

with MeSH for specificity

10

Subheadings coordinate with MeSH

= /immunology

/pathology

11

MEDLINE Licensees

12

What’s in PubMed? Equivalent to Medline?

includes:• records for online books & chapters• out of scope articles

13

How to Search PubMed

aids drugs breast feeding

http://www.pubmed.gov/

14

Results (most recent)

Automatic term mapping Automatic explosion Citation sensor New filters, left hand side Links to the open web PubMed mobile

http://www.nlm.nih.gov/mobile/

15

Best features in PubMed …?

ATM checks these fields for mapping properly Medical subject headingsJournal titles

Authors

16

PubMed uses Automatic Term Mapping

…which recognizes thousands of concepts & maps to the most appropriate terms …

http://www.pubmed.gov/

‘Search details’ translates your query

…yes, to improve your search

17

http://www.pubmed.gov/

18

MEDLINE’s database of biomedical research is the heart of PubMed

Includes quality journals seen as important by experts

MEDLINE can be searched freely via PubMed; also on other systems

MEDLINE is enhanced by Medical Subject Headings (MeSH), which improve access to literature, enhance searching & preservation

Summary

Dean Giustini | UBC Biomedical Branch Librarian | June 20th 2012A talk for researchers at the RHNH Research Centre

dean.giustini@ubc.ca