Searching Medline Alex Denby Regional MI Manager London Medicines Information Service (Northwick Park Hospital)

Main issues/problems General Searches produce irrelevant hits – how to you find relevant hits for your topic? Difficulty finding good quality full text articles Not using to full potential Searching techniques Finding/deciding which are the relevant search terms to use –use of the MeSH /EMTREE terms MeSH terms not updated very often – drug names CAS no searches vs. free text Free text searching which field to sue Different thesaurus for the 2 databases

NLH Software Problems Slow and crashes all the time Doesn’t reliably save articles No results displayed even though hits found Takes a long time to do searches

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

Boolean operators A NOT B AB A OR B AB A AND B AB

A OR B AB A NOT B A B A AND B AB 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: 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 (allowable 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

e.g. AE: adverse effects DU: diagnostic use PK: pharmacokinetics TU: therapeutic use

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 (i.e. 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: Click “Login now” (LHS of screen) Right click & then click on “create a shortcut” Enter Athens password Click on “Healthcare Database Advanced Search” and select Medline.

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….

ANY QUESTIONS?