Searching Medline Helen Rowlandson Medicines 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 B AB A OR B AB 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:  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? MEDLINE OVID MEDSCAPE SILVER PLATTER PUBMED NLH

National Library for Health software  Open Internet and type:  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….