Support : Publications : Chronolog Archives : September 2001

EMBASE^® for Current and Comprehensive Drug and Medical Research

EMBASE (Dialog Files 72, 73; DataStar Files EMED, EMZZ), produced by Elsevier Science, has long been renowned as an excellent resource for bibliographic searching in biomedicine and pharmaceutical literature. A number of changes and enhancements over the past several years have added to the database's value as an essential drug research tool.

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Facts and figures about EMBASE

File size: Over 8.5 million records from 1974 to present

Update frequency: Weekly

Sources indexed: Over 4,000 journals from 70 countries

Average record processing time: About 10 working days

Over 80% of records contain original author abstracts. Approximately 75% of EMBASE records cite English-language documents.

Core subject areas:

• Drug research, pharmacology, pharmaceutics, pharmacy and toxicology
• Human medicine (clinical and experimental)
• Basic biological research relevant to human medicine
• Health policy, management, and pharmacoeconomics
• Public, occupational, and environmental health
• Substance dependence and abuse
• Psychiatry
• Rehabilitation and physical therapy
• Forensic medicine
• Alternative medicine
• Biomedical engineering, instrumentation, and medical devices
• Biotechnology

Additional disciplines covered include nursing, dentistry, vet

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EMTREE, the EMBASE thesaurus

EMBASE records are indexed with subject headings from the EMTREE thesaurus, a collection of over 42,000 drug and medical preferred terms (descriptors), organized in a cascading tree structure that ranges from broad concepts (e.g., chemicals and drugs) to very specific terms (e.g., prednisolone acetate), represented by 10,000 tree codes. In addition, EMTREE contains over 180,000 synonyms as added entries to preferred descriptor terms; synonyms include:

• Various drug generic nomenclatures (whenever possible, drugs are indexed in EMTREE with International Nonpropri-etary Names) — USAN, BAN, etc.


• Chemical compound names


• Laboratory codes


• CAS^® Registry Numbers (also searchable in the RN= field and in the RN paragraph)


• Drug product names, registered trademarks, etc.


• Variants of disease names


• MeSH subject headings from the U.S. National Library of Medicine

EMTREE terms can be exploded to retrieve narrower, more specific terms within
subject hierarchies (e.g., s antineoplastic agent#). EMTREE can be accessed online via the EXPAND command. The online thesaurus shows preferred terms (descriptors), synonyms, broader and narrower terms, and EMTREE codes. On Dialog, it is especially useful for retrospective searches on drugs, as old and replaced drug names (displayed as synonyms) are listed along with current names; they can be searched together when comprehensive retrieval is necessary. (See Example 1)

The online thesaurus lets Dialog and DataStar searchers retrieve additional records indexed to old or changed names (listed as synonyms) that would be missed by searching the preferred term alone.

Example 1
Note: THES ALLERGRA will give a similar list of selectable terms on DataStar.

• U = use (preferred term)
• B = broader term
• S = synonym

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CAS® Registry Numbers

EMBASE has Chemical Abstract Service Registry Numbers for about 14,000 substances in EMTREE. They are directly searchable in the RN field (e.g., s rn= 30516-87-1 on Dialog or 30516-87-1. RN. on DataStar). Before the recent EMBASE reloads, they only retrieved records added from 1988 forward; they now work across the entire database, back to 1974.

CAS Registry Numbers are included as synonyms in EMTREE, and are available in the online thesaurus via EXPAND as pointers to preferred EMTREE drug names:

? e (rn=30516-87-1)

Ref   Items Type  RT  Index-term 
R1    10346        1 *RN=30516-87-1 
R2    10655   S   25  ZIDOVUDINE

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Routes of drug administration links

For over a decade, EMBASE indexers have qualified EMTREE terms with drug and disease "links," or subheadings, that identify very specific aspects of subjects and allow great precision in query building (e.g., diazepam (link) adverse drug reaction). In 2000, an additional 47 links identifying specific routes of drug administration were added; for example, diazepam (link) oral drug administration. These subheadings are assigned by indexers to identify both novel and routine routes of administration; if the route is a significant aspect of the article (for example, a novel route), the term drug administration is also linked to the drug name. See below for a list of link subheadings for routes of drug administration. DataStar searchers can display a list of all link subheadings online with the command ..D SH (display subheadings).

Link subheadings for routes of drug administration (Dialog):

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Quick explodes on DataStar

Pre-defined clusters of headings have been created on DataStar for greater convenience in searching related links together:

Example:

1_: quinolone-derived-antiinfective-agent# with qx

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Clinical trial searching: Key descriptors

A special class of subject terms, called descriptors, are used to identify routinely-indexed concepts such as human and animal study types, patient sex and age, patient population size, item (document) types, etc. Of particular interest to pharmaceutical researchers, evidence-based medicine specialists, and others are descriptors for clinical trials and specific study designs:

• Clinical trial
• Phase 1 clinical trial
• Phase 2 clinical trial
• Phase 3 clinical trial
• Phase 4 clinical trial
• Meta analysis
• Randomized controlled trial
• Double blind procedure
• Single blind procedure
• Crossover procedure
• Multicenter study
• Controlled study

Note: Many of these are available as special options on DataStarWeb and DataStar for Windows--just click the box to select them.

The routine, consistent use of these terms according to specific guidelines ensures reliable retrieval for these study types.

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Molecular sequence numbers

Biotechnology-related records now contain molecular sequence numbers; these identify accession numbers for sequences found in various databanks and repositories. It is helpful for searchers looking for information on novel therapeutics and related topics.

Nucleotide sequence numbers:

• GENBANK
• EMBL (European Molecular Biology Laboratory)
• DDBJ (DNA Data Bank of Japan)

Protein sequence numbers:

• SWISSPROT
• PIR (Protein Identification Resource)

This field contains both the databank name and sequence accession number (e.g., GENBANK AA 262366). It is available on both Dialog and DataStar:

s sq=aa230649

1_: aa230649.ds.

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EMBASE Alert

EMBASE Alert (Dialog File 172; DataStar File EMBA), a companion database to EMBASE, is a "rolling" file that contains the most current eight weeks of in-process EMBASE data -- bibliographic citations and abstracts that have not yet undergone subject indexing. Making database records available online 5 to 10 days earlier than EMBASE, it is a valuable tool for current awareness on hot and newsworthy topics.

Because EMBASE Alert has no subject indexing or coding, it can be searched easily with free text:

?s (sumatriptan or triptan?) and (headache? or migraine?
or antimigraine?)

Learning more ...

Call the Knowledge Center at 800-3DIALOG (334-2564) for additional information on searching EMBASE. Elsevier Science holds free public training sessions on EMBASE; many of these sessions are held at Dialog offices. EMBASE is also covered in Dialog's Biomedical Information Seminar; see here for details.

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