Searching Medline

1. Searching Medline Helen Rowlandson Principal Medicines Information Pharmacist London Medicines Information (Northwick Park) London

2. July 2008 course - participants responses • 17 questionnaires returned • More than half have had formal training (during pre-reg, at university, during diploma/certificate, or by NHS library service) • Nearly all have had informal training in-house in MI service • Most participants have used Dialog and a few use Ovid or Pubmed • Only a few have starting using NLH regularly

3. Main issues/problems • Searches produce too many hits - how do you narrow/limit your search down? • Searches produce irrelevant hits – how to you find relevant hits for your topic? • Difficulty finding good quality full text articles • Finding/deciding which are the relevant search terms to use –use of the MeSH browser/ MESH descriptors/MESH headings/thesaurus • Use of explode function

4. National Library of Health (NLH) Interface Issues • Slow and crashes all the time • Thesaurus unavailable at times • Map to Thesaurus button is not automatically ticked • More hits with Dialog

5. Plan • Searching basics – a refresher • What is Medline? • Medical Subject Headings (MeSH) • NLM’s MeSH browser • Searching tools • NLH software – the basics • Worked examples

6. 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

7. Boolean operators • A AND B A B A OR B A B A NOT B A B

8. 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

9. 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

10. 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

11. 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”

12. MeSH Examples • Kidney Failure • Depression • Chronic Fatigue Syndrome • PTSD • Fluoxetine

13. 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

14. 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?

15. 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

16. 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

17. 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

18. 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

19. Quick question… • What is directly above olanzapine in the MeSH tree? • What is its CAS registry number?

20. Medline & MeSH Recap • Successful searching is finding correct indexing term • MeSH headings • Scope Notes • Focus/Explode • Subheadings/Check Tags • Supplementary concepts

21. Accessing Medline? SILVER PLATTER PUBMED MEDLINE OVID NLH MEDSCAPE

22. 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

23. NLH software • Search one database at a time • Medline 1950 to date • 2 options to search for terms: • Thesaurus mapping • Browse headings

26. NLH software • Major /Explode • Tree structure • Subheadings • Supplementary Concepts • Limits • Show titles

28. Worked example 1 • Are there any recent papers about SSRIs or SNRIs being used in the treatment of Huntington disease?

31. Worked example 2 • Are there any recent RCTs of the UK-available acetylcholinesterase inhibitors (galantamine, rivastigmine, donepezil) in Lewy Body Dementia?

35. 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….

38. ANY QUESTIONS?