BLITS: Getting the Best fromEMBASE.com

Embase: Systematic Searching

MLA 2011,

Minneapolis Convention Centre

Minneapolis, MN

Planning a Systematic Review

Planning the search strategy and process in advance helps you to:

•Systematically retrieve the maximum number of highly relevant references

•Extract the available evidence

2

A checklist may be used to review the search or used to help set up a well planned search

Reviewing Search Strategies

4

• Checklist is taken from: Jessie McGowan, Margaret Sampson, Carol Lefebvre. An

Evidence Based Checklist for the Peer Review of Electronic Search Strategies (PRESS EBC). Evidence Based Library and Information Practice 2010;5(1):149-54.

• The following article also helped inspire this presentation: Sampson M, McGowan J, Cogo E, et al. An evidence-based

practice guideline for the peer review of electronic search strategies. Journal of Clinical Epidemiology 2009 (Sep); 62(9): 944–952

Choosing your database

There is some evidence of added value in searching Embase, as well as MEDLINE, for studies for inclusion in systematic reviews, as the additional studies identified contribute to the overall findings of the review; this may be attributed in part to the greater coverage of some languages other than English in Embase.

Lefebvre C, Eisinga A, McDonald S, Paul N. Enhancing access to reports of clinical trials published world-wide – the contribution of EMBASE records to the Cochrane Central Register of Controlled Trials

(CENTRAL) in The Cochrane Library. Emerging Themes in Epidemiology 2008;5:13.

Emtree: Biomedical thesaurus, over 60k terms

Embase: Fully indexed: Over 7,700 journals, 1974-

MEDLINE: 2,500 journals unique to Embase, mapped to Embase

indexing, 1950- (including MEDLINE Classic)

Embase Classic:

Digitally scanned and

re-indexed, 1947-1973

AIP and In Process:

Indexing added, from 2009

Conference Abstracts:

Indexing added, from 2009

1947 1950 1974 2009

Embase Content Overview

Unique content in Embase

• ‘Embase is a rich source of reports of randomized trials that are either not included in MEDLINE or not indexed as trials in MEDLINE, especially reports in some languages other than English’.

• ‘In addition to searching CENTRAL, people looking for reports of randomized trials should search Embase, as well as MEDLINE, for reports published in recent years that have not yet been considered for inclusion in CENTRAL’.

Presented by Carol Lefebvre MLA 2010

Ref: Lefebvre et al. Emerging Themes in Epidemiology 2008 5:13

Language Embase MedlineEmbase

advantage Percent

Turkish 613 75 538 717%

Korean 134 46 88 191%

Portuguese 712 442 270 61%

Dutch 606 442 164 37%

Chinese 5366 3945 1421 36%

Polish 491 434 57 13%

Spanish 2316 2137 179 8%

French 3952 3904 48 1%

German 8393 8566 -173 -2%

Embase vs MEDLINERandomized controlled trials

Search date: 14 June 2010

Conferences

• 2009 – Elsevier started indexing conference abstracts in Embase• Currently nearly 400K conference abstracts in Embase

from 1K conferences• Each abstract is searchable using Emtree• Currently adding nearly 1K abstracts per day

• from journals and journal supplements published in 2009/2010/2011

• Conference abstracts are not in MEDLINE• In BIOSIS for 2009/2010: “less than 165,000 records,

of which just 11% have online abstracts”• See

http://www.embase.com/info/what-is-embase/coverage for more information

Sample Review Question

12

Are there any risks associated with the administration of antibiotics together with digoxin in a patient with congestive heart failure who has contracted pneumonia?

Emtree (from Jan 2011)

• 60K preferred terms (more than 29K drugs and chemicals, including all generic names recognised by FDA, EMEA and WHO from 2000)

• >260,000 synonyms (>172,000 drugs and chemicals)• 7,500 explosion terms (that define the hierarchical structure)• 78 subheadings (64 drug and 14 disease subheadings)• 14 study types including Randomised Controlled Trial,

Systematic Reviews and the NEWLY introduced Diagnostic Test Accuracy Study

• Links to over 21,000 CAS registry numbers• All MeSH terms are included• Updated 3 times a year (from 2011)

Benefits of Emtree

• Easy to search for terms and all synonyms• Comprehensive drug searching• Up-to-date • Explosion (tree) searching• Polyhierarchical structure• Natural language terminology• Inclusive terminology• Review www.embase.com/info/emtree for more

information

Start with Emtree

15

Find subject headings for your search

Click here to search further in an Embase search form.

Click “nn Records” link to perform an explosion search, if applicable.

Reviewing an Emtree term

16

Take note of any Synonyms listed

Consider the term’s History

Look at the CAS registry number(s) displayed

Read the entry provided from Dorland’s dictionary, when available

Emtree Term History

• If your term has not always existed in Emtree (this is after 1974), then perform a Field search of Article title (:ti) using your term• Review the Emtree terms in your retrieved records and

consider adding these subject headings to your search strategy

• Review the abstracts to identify any alternative expressions used by authors to add as additional free text search terms.

17

Free-text Term Searching

18

Perform a free text search for the Emtree term and all synonyms in the title and abstract fields.

Search unique fields

19

Include the Drug trade name (:tn) field with the Article title and Abstract fields, where appropriate Include the CAS registry number (:rn) displayed in the Emtree record, when available

Cannot find an appropriate Emtree term?

• Perform a free text search in the article title field(:ti) using your term

• Look through the resulting list of records and use “Add to Clipboard” link for any articles deemed relevant

20

Further tips for free text searching in Embase (Elsevier only)

• Consider using truncation or wildcard characters (*, ?)• Proximity operators are supported such as NEXT and

NEAR• When performing free-text searches, remember to

consider variant spellings including British and American spellings and terminologyo e.g., tumor vs tumour; diaper vs nappy; pediatric vs

paediatric; otorhinolaryngology vs ear, nose and throat; overuse injury vs repetitive strain injury

• Refer to www.trainingdesk.elsevier.com/embase and the Quick User Guide for more guidance

21

Filters

23

The most common type of search filter is for specific study types, found in Filters on Session Results.Other filters may include publication type .

Diagnostic Test Accuracy Study

•Definition: Used for original studies or systematic reviews which assess how accurately a test distinguishes humans or animals having a condition or disease from those who do not. Typically, the test under evaluation is called the index test and its results are compared to the results of the best.

•Previously: Did not exist

•From 2011: This is a new check tag and unique to Embase

Embase study types

• Go to http://pbt.up2els.com/sites/default/files/Embase%20check%20tags%202011%20(4).27April2011.pdf for a list of Embase study types and their definitions.

Save Search and Email Alert

26

Coming in June 2011

Searches are saved with all steps of the strategy clearly visible. The user, can update and rerun saved search strategies

Coming in August 2011:Editing your saved searches

Saved searches can be edited, and changes previewed and accepted.When rerun, the result count will be updated

Thank you!

Contact us: http://embase.com/info/contact-us