An introduction to Medline
(CMM2)
Medical Subject Librarian Team
Session outline and outcomes
The session will include:
•
•
•
•
some information about the Medline database
the components and techniques of database searching
a demonstration of a typical Medline search
a practical exercise
By the end of the session you should have a better
understanding of:
• the formulation of a successful database search strategy
• the Medline indexing process
• how to interpret and use your search results
Why?
• Why have this session?
•
Why use journals?
•
Why use databases?
•
Specifically, why use Medline?
Medline - some facts and figures
• Database provided by the US National Library of
Medicine (therefore has a US bias)
• Content includes basic research and clinical
sciences
• Contains over 14 million records
• Indexes over 4,600 core biomedical journals
• Searchable back to 1950
• Updated weekly
Using Medline via the OvidSP platform
• Lecturers will often refer to searching Medline
via PubMed
• Searching Medline via OvidSP allows you to see
more clearly how you achieve your results
Medline: an example search
Let’s say we want to find journal articles published
on the subject of:
Brain tumours related to mobile phone use
Before starting your search ask yourself:
• What are my keywords?
• Are there any other ways to spell the keywords?
• Are there any other words which mean the same
thing (synonyms)?
• Are there any related keywords I want to
include?
Identify keywords, synonyms and related
keywords
Brain tumours related to mobile phone use
Brain tumour
Mobile phone
Brain cancer
Intracranial tumour
…malignancy
…carcinoma
…neoplasm
…tumor
Cellular phone
Cellphone
Electromagnetic fields
Radio waves
Radiation
Combine your terms using Boolean logic
To combine synonyms use search operator ‘or’
Brain tumour
or
Intracranial
tumour
Combine your terms using Boolean logic
To combine concepts use search operator ‘and’
Brain tumour
and
Mobile phones
Combine your terms using Boolean logic
To exclude unwanted terms use search operator ‘not’
Mobile phones
not
Hearing loss
Combine your terms using Boolean logic
Your combined search will start to look something like this:
Brain tumour
or
Intracranial
tumour
Mobile phone
and or
Cellular phone
or
or
Brain neoplasm
Radiation
Medline: methods of searching
• Search by Medical Subject Headings (MeSH)
• Search by text words
Both approaches needed for good quality searching
Medline – MeSH searching
What is a ‘MeSH’ search?
• MeSH = Medical Subject Headings (a thesaurus)
• Indexer reads entire article (not just the abstract) and
assigns headings from this thesaurus to describe its
contents
Why use it?
• Synonyms come under one preferred heading
(e.g. ‘brain neoplasms’ will retrieve articles on brain or
intracranial cancers, tumour, tumor, carcinoma etc)
http://metalib.bris.ac.uk
Select Find
database
Find database
medline
Find database
Click on
Medline link
University of Bristol Single Sign-on
The OVID platform
Select Medline 1950 to present
MeSH: select Advanced Ovid Search tab
Use Ask a University of Bristol Librarian
to get feedback on your search
Select Advanced Ovid Search
MeSH: entering a search term
brain tumour
MeSH: mapping display
Check the Scope Note
MeSH: scope note
Back to Previous Page
MeSH: select a term
Choose Brain Neoplasms
MeSH: the tree structure
Click Continue
Explode your term
MeSH: subheading display
Click Continue
Choose Include All
Subheadings*
* Think inclusively at the early stages of a search
BUT note down any subheading codes for potential later use
MeSH: first search result
Click Search History to expand
MeSH: combining terms 1
1 and 2
MeSH: combining terms 2
When to search by text word
Searching by text word searches for the exact words in the
titles or abstracts of all papers on the database
If MeSH is so good, why use the text word option?
• If the topic is a new one there is unlikely to be a MeSH
term
• Sometimes the MeSH term is too general to be of use
• Sometimes the appropriate MeSH term will elude you
• Helps overcome possible errors or omissions – indexers
are only human!
Text word searching: wildcards
• * Pollut* - will give you pollute, polluter,
polluting, pollutant, pollutants,
pollution etc
$ also works in this way in OvidSP
• # Often useful with American spelling - e.g.
ioni#ation will find both ionisation and
ionization (represents a single character)
• ? colo?r finds color or colour (zero or one
character)
Text word searching 1
Select Search Fields
Text word searching 2
(brain or intracranial) adj2 (cancer* or tumo?r* or carcinoma* or malignan* or neoplasm*)
Select Text Word
Text word searching 3
(1 or 4) and (2 or 5)
Text word searching 4
How to refine your results
Too few hits?
• Think of all possible MeSH and text word terms
(synonyms, alternative terminology/spelling) for each
concept and link the related terms using OR
• Check your spelling
• ‘Explode’ your mesh searches and include all subheadings
• Use truncation when conducting text word searches
Too many hits?
• Use more precise search terms
• Add additional search terms to existing search sets using AND
• Restrict your mesh searches to ‘focus’
• Specify subheadings
• Apply limits
MeSH: restricting to focus
*3
MeSH: specifying a subheading
1/ep
MeSH: specifying a subheading
MeSH: limits
Select Additional Limits
MeSH: additional limits
Practical work
• In pairs or threes, work through the question
sheet
• Take your time and work collaboratively - the key
to the practical work is understanding what you
are doing, not the speed in which it is completed
Any questions?
For further help:
Contact the Medical Subject Librarian team:
• Email: medical-librarians@bristol.ac.uk
(or use the ‘Ask a University of Bristol Librarian’
link in Medline)
• Telephone:
(0117) 331 1504