Searching EMBASE

Joanne McEntee

Medicines Information Pharmacist North West Medicines Information Centre

SEARCHING EMBASE

National Training Course

Session aims

• To understand the differences between Medline

and Embase.

• To know that Medline records are included in

Embase and understand how this is done.

• To understand why you need Medline AND

Embase.

• To know how the EMTREE thesaurus is organised.

• To know how to search Embase.

• To practise searching Embase (and Medline).

Plan

• What is Embase? (see pre-course material)

• Medline vs. Embase (see pre-course material)

• Medline on Embase

• EMTREE thesaurus

• Search tools in NHS Evidence/OVID

• Worked examples

Medline on Embase

• Since Jan 2010, Medline records are included in

Embase.

• On all platforms including Ovid.

• Daily feed from Medline to Embase.

Medline on Embase (continued)

De-duplication process

• Medline covers 2,500 unique journals (and 3,000

common ones).

• If record already in Embase, Medline record not

added, but de-duplication not 100%.

• If same record subsequently added that is

indexed by Embase, the Medline-unique version is

replaced.

Medline on Embase (continued)

Indexing of records

• MESH terms are mapped to EMTREE terms –

abstracts are not re-keyworded.

• All records can be searched using EMTREE or

MESH terms.

Medline on Embase (continued)

Publication type index

• >50 publication types indexed in Medline vs.

8 in Embase.

• These mapped to Embase publication type

or EMTREE term

e.g. clinical trial is publication type in Medline and EMTREE term in Embase.

Medline on Embase (continued)

MESH sub-headings

• Medline sub-headings are mapped to EMTREE

sub-headings where possible.

• E.g. adverse effects > adverse drug reactions .

• There are 19 equivalent terms.

• 61 MeSH sub-headings mapped to EMTREE terms

• E.g. contraindication (SH) > drug contraindication (ET).

Medline on Embase (continued)

Checktags

12 Medline checktags:

• 8 map directly to EMTREE terms (animal, case report,

comparative study, male, female, human, in vitro,

pregnancy).

• 4 are ignored (not relevant).

Should you search only Embase?

As well as incorporating Medline……..

• Embase records have more keywords vs. Medline.

• Embase indexes abstracts from 800 conferences a year (since 2009).

• Embase indexes ‘articles in press’ from 1,500 journals.

• EMTREE twice as large as MeSH.

• EMTREE includes more drug names and more are added 3 times a year.

Why you still need Medline…..

• Indexing is subjective and the methods differ between Medline and Embase.

• More subheadings are available in Medline (for all subjects since 1966 vs. drugs and diseases only since 1988 in Embase), allowing a more precise search.

• Fields, limits and subject structures are different.

Searching EMBASE

• Controlled vocabulary = EMTREE

• Uses natural language

• US spellings rather than British

• INNs used where possible

• Acronyms & abbreviations can be used

• Tree Structure (15) – Hierarchy

• Indexing: Terms added/Drug names

NICE Evidence Search

• www.evidence.nhs.uk

• Click ‘Journals and databases’

• Click ‘Healthcare databases advanced search’

• Type in your Athens password

• Select Embase.

• Embase 1974 to date

• 2 options to search for terms:

• Thesaurus mapping

• Browse headings

NICE Evidence Search and Ovid software

Explode/Major descriptor

Select • finds all articles where the term is listed (alone or with

subheadings or if a major term).

Explode • Searches for the term and all the terms below below in the

tree structure.

• ‘exp’ is put before keyword in results.

Major descriptor (focus) • Only includes articles where the keyword (descriptor) is the

main focus of the article.

• ‘ ’ is put before keyword in results.

Subheadings

• Two types – drugs and diseases

• Fewer subheadings for diseases than Medline

• Many more subheading options for drugs than

Medline, e.g. diclofenac

• Can select more than one subheading

CAS numbers

• No need to use them in EMBASE.

• Most medicines have EMTREE terms – even

recently licensed ones.

• If a drug hasn’t got an EMTREE term assigned –

use free text.

Limits

• Limit searches in similar way to Medline.

• Differences compared with Medline.

Publication types

• Publication types have their own facet / tree

top of EMTREE terms that are searchable.

• Facet J: types of article or study.

• Build up your search and combine in the usual

way (using BOOLEAN) with other search terms.

Worked example 1

Workshop question 1

Are there any papers specifically about using

linezolid to treat MRSA?

Worked example 2

Workshop question 2

Are there any review articles about inhaler use

in children with asthma aged under 4?

Worked example 3

Workshop question 5

Is there any evidence that minocycline is more

effective than any of the other tetracyclines

licensed for treating acne (tetracycline,

lymecycline, oxytetracycline, doxycycline)?

Getting help

ANY QUESTIONS?