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Searching Medline
Helen RowlandsonMedicines Information Manager
Northwick Park Hospital, London
Plan Searching basics – a refresher What is Medline? Medical Subject Headings (MeSH) NLM’s MeSH browser Searching tools NLH software – the basics Worked examples
Searching basics – a refresher
Large databases – electronic searching is essential
A controlled vocabulary or a thesaurus is necessary
A means of combining terms is also required e.g. BOOLEAN operators
A AND BA B
A OR BA B
A NOT B A B
Boolean operators
What is Medline?
Vast source of medical information Medicine, Dentistry, Veterinary, Psychology
Covers Clinical medicine, anatomy, pharmacology,
toxicology, genetics, microbiology, pathology, environmental health, occupational medicine, psychology, biomedical technology
5,000 journals indexed, 70 countries
Searching Medline
Use indexing system - MeSH thesaurus Controlled vocabulary with ~24,000 descriptors Each represents a single concept Tree structure - hierarchal Constantly changing 600+ added per year
Medical Subject Headings
Articles indexed by 3 tier system MeSH descriptor (MeSH heading) MeSH qualifier (MeSH subheading) Items mentioned (check tags) Articles are indexed & then double checked by
another indexer must agree
MeSH Browser
Open the Internet and type:
http://www.nlm.nih.gov/mesh/MBrowser.html
Right click & then click on “create a shortcut”
Now click on “Navigate from tree top”
MeSH Examples
Kidney Failure Depression Chronic Fatigue Syndrome PTSD Fluoxetine
Searching Tools
Explode Includes everything below in the tree structure
Focus (Major) Only includes articles where the MeSH heading
(descriptor) is the main focus of the article
Quick questions…
What is the correct MeSH term to use for angina?
And if you exploded this term, what term(s) would you be also including in your search?
Subheadings (qualifiers)
Subheadings (qualifiers) refine your search What aspect of the main heading is the author writing
about or discussing? Look at the definitions of the subheading e.g.:
Administration and Dosage Adverse Effects Analysis Chemistry Diagnostic use Economics History
Check Tags All relevant tags are attached to the article These are essentially used as “limit” functions
Human Child Adult Aged Male Female etc..
Type in “female” and look at annotation
Check tags
Limits – publication types
If you want to search for papers that are meta analyses use the publication type limit function. Articles will then be meta-analyses
If you use the MeSH heading ‘meta-analysis as a topic’ from tree E the articles you will get will be about meta-analysis as a study design(methods etc..)
Look at the MESH browser for definitions
Supplementary Concepts
Searches for substances that are not defined in MeSH (ie don’t have MeSH terms)
Supplementary chemical record >30,000 substances undergoing clinical
development – but not all will become commercially available medicines
Depending on software - search by CAS registry number or free text
Quick question…
What is directly above olanzapine in the MeSH tree?
What is its CAS registry number?
Medline & MeSH Recap Successful searching is finding correct
indexing term MeSH headings Scope Notes Focus/Explode Subheadings/Check Tags Supplementary concepts
Accessing Medline?
MEDLINEOVID
MEDSCAPE
SILVER PLATTER
PUBMED
NLH
National Library for Health software
Open Internet and type:http://www.library.nhs.uk/Default.aspx
Log in using athens username and password”
Healthcare databases advanced search
NLH software
Search one database at a time Medline 1950 to date 2 options to search for terms:
Thesaurus mapping Browse headings
NLH software
Major /Explode Tree structure Subheadings Supplementary Concepts Limits Show titles
Worked example 1
Are there any recent papers about SSRIs or SNRIs being used in the treatment of Huntington disease?
Worked example 2
Are there any recent RCTs of the UK-available acetylcholinesterase inhibitors (galantamine, rivastigmine, donepezil) in Lewy Body Dementia?
Worked example 3
Are there any articles which discuss using high dose vitamin supplementation to treat autism?
NB – remember that your enquirer’s way of describing what he is asking for may not necessarily be exactly how MeSH describes it….
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