Embase Literature Search Assignment

Boolean Logic

Embase has more Boolean search options than Medline, using AND, OR, NOT, NEAR and NEXT

AND, OR and NOT operate in the same way that they do in PubMed

An explanation of the use of the proximity operators NEAR and NEXT is below.

Proximity operators let you search for words or phrases at any specified distance from each other.


This will find terms which are within 'n' words of each other, in either direction.

cardiac near/5 catheter would find the two words within five words of each other in either direction:

"Despite complicated cardiac anatomy, catheter ablation of ."
"... patients undergoing catheter ablation for cardiac arrhythmias ..."
"...a continuous thermodilution cardiac output pulmonary artery catheter."

Note: If you want to add a field name to your proximity searches make sure you enclose the search terms in parentheses.

(cardiac near/5 catheter):ti,ab


This will find terms which are within 'n' words of each other in the order specified.

hip next/3 prosthesis would find the two words within three words of each other, but hip would always have to come first

"... rheumatoid arthritis, joint surgery, hip or knee prosthesis ..."
"metal on metal hip resurfacing, prosthesis failure (complication, diagnosis)..."

Note: If you want to add a field name to your proximity searches make sure you enclose the search terms in parentheses.

(hip next/3 prosthesis):ti,ab

Emtree - what is it (and why do I need to know)?

Like Medline Embase has its own thesaurus of indexing terms. This is called Emtree, and is a hierarchically structured, controlled vocabulary - the equivalent of Medline’s MeSH. Each journal article included in Embase is indexed with terms from the thesaurus to represent its subject content.

Emtree is where the real search power of Embase lies, so it's worth taking a few minutes to understand how it works. It has a hierarchical structure, very like the MeSH thesaurus in PubMed, with the ability to "explode" terms to search for more specific subcategories.


'neoplasm'/de - will find articles on neoplasms as a general category, but NOT specific neoplasms

'neoplasm'/exp - will find articles on neoplasms as a general category, AS WELL AS articles on specific categories of neoplasms listed below the main heading

Each Emtree term will also have a list of synonyms (the equivalent of the Entry Terms you find in MeSH), and these can be searched in titles and abstracts of articles.

There is a third extremely useful option available for Emtree terms.

‘neoplasm’/syn - will explode the term neoplasm.

It will also search the term neoplasm in all other indexing fields


It will search the Synonyms listed in Emtree under neoplasm, in all fields.


acral tumor; cancer; cancers; neoplasia; neoplasms; neoplasms by histologic type; neoplasms, cystic, mucinous, and serous; neoplasms, embryonal and mixed; neoplasms, germ cell and embryonal; neoplasms, glandular and epithelial; neoplasms, hormone-dependent; neoplasms, post-traumatic; neoplastic disease; section 16; tumor; tumour

However it will search the specific forms of cancer listed under 'neoplasm' only as indexing terms. It will NOT search them in other fields.

Field Names

Like Medline, Embase has a variety of searchable Fields. These are an extremely useful aid in improving the accuracy of your searches. In fact they are essential for higher degree searching.

Some of the most commonly used are


Author's Nameau

‘gold a’:au
‘gold a’:au retrieves all authors named A. Gold, with or without middle initials; truncation character not needed

‘gold a p’:au
'gold a p:au retrieves only authors with both initials

Article Titletibioterrorism:ti
Index term (Emtree subject descriptor)de

There are two options here:-

/de – to search for an exact Emtree heading


This search will retrieve articles indexed ONLY with the exact index term neoplasm . It will NOT find other indexing terms in which the word neoplasm appears

:de - to search for words or phrases anywhere in an Emtree  heading


This search will retrieve articles where the word neoplasm occurs somewhere in the Emtree heading. So it will include the first option, but will find additional material where the word neoplasm is embedded in the heading. e.g. myeloproliferative neoplasm

Explosion (Emtree index term)exp


This will retrieve narrower, more specific terms in the subject tree, as well as the general term neoplasm. It will NOT search synonyms

Emtree and synonyms search /syn


This search will explode the Emtree term and search that term in all searchable fields. All of the Synonyms listed in Emtree for that term will also be searched in all fields. The narrower terms in the exploded subject tree will be searched only as indexing terms


A full list is here

A word or phrase can be searched in multiple fields simultaneously

eg. “cancer gene therapy”:de,ti,ab will search for the phrase in Emtree, in titles of articles, or in abstracts of articles.

To search a word or phrase in ALL FIELDS simply type it into the Quick Search box, and uncheck the "Search as Broadly as possible" box 

Using Subheadings

Subheadings are searched as two-letter qualifier codes with drug terms (dd) or medical terms (dm). Subheadings and their abbreviations are listed at  drug subheadings, routes of drug administration and disease subheadings. They can be searched alone or in groups (separated with commas); major or explosion can also be added.

eg. ‘colon cancer’/dm_dt


   ‘antineoplastic agent’/exp/dd_pk/mj

Subheadings can also be searched alone as “free-floating” or "floating" subheadings; i.e. not attached to a specific index term, using lnk.

eg. ‘adverse drug reaction’:lnk

   prevention:lnk and [2009]/py 

Phrase Searching in Embase

Enclose phrases in quotation marks (it doesn’t matter whether they are single or double quotes, as long as they match).  If quotes are omitted, each word is mapped separately and unmapped words are searched as free text, and combined with a Boolean AND, resulting in potentially irrelevant hits.

heart attacks   is searched as   heart AND attacks   -  and the two words may be nowhere near one another

"heart attacks"   is searched as  "heart attacks"   -  in other words, only that exact phrase will be found

Hyphens are also interpreted as phrases

well-being is searched not only as a hyphenated word, but also as the phrase "well being"

Wildcards (truncation symbols) can now be used within phrases

Types of Publication Indexed for Embase

ArticleOriginal research or opinion
Article in PressIntroduced 2009
Conference abstractAbstract or poster item presented at a conference
Conference paperFull report of material presented at a conference including published conference summaries, but excluding conference abstracts
Conference reviewReview summarising conference abstracts presented at a single conference
EditorialProviding a summary of one or more articles in a journal issue, or providing general editorial news
ErratumReport of an error, correction or retraction of a previously published paper
LetterLetter to or correspondence with the editor
NoteItem defined as a note in a journal, also including discussions and commentary
ReviewSignificant review of original research, usually with an extensive bibliography
Short surveyShort, or mini-review of original research; usually shorter, and with a less extensive bibliography than a review

Wildcard and Truncation Symbols

In Embase two options are available.

* An asterisk allows for variable truncation, and can be used either within a word, or at the end of a word. It can allow for any number of characters or the absence of a character

sul*ur  - retrieves sulfur, sulphur

catheter*  - retrieves catheter, catheters, catheterization, catheter-assisted

?  A question mark allows for only one character. It does not allow for the absence of a character

sulf?nyl retrieves records that contain words like 'sulfonyl' and 'sulfinyl'

Wildcards (truncation symbols) can now be used within phrases


Limits are best applied once a search is completed, and  include publication dates,  publication types, areas of focus, languages, patient age groups, gender, etc.

The limit options listed on the results page are not comprehensive, so for some categories it's best to check Emtree. For example if you look up Types of Study in Emtree, you will find many more options than appear under Study Types on the Results page.

The two limits you are most likely to use are probably:-

Date limits:-

/py (publication year range),

/sd (‘since date’) and

/wd (‘within date’).

Formats for /sd and /wd and YYYY/MM/DD.


Reviews on AIDS published within the last 5 years
‘aids’/mj AND [review]/lim and [2005-2009]/py

Papers by oncologist J.C. Smith indexed since mid-2002
‘smith j.c.’ :au AND [cancer]/lim and [01/07/2002]/sd

Articles from the last 14 days from the journal Cell
‘cell’/jt AND [14]/wd

If you attempt to use the date limits from the Results page, prefer the Date tab on the toolbar at the top of the screen. If you use the date limits from the Text Filters column on the left of the screen, you'll need to click on the Graphics option at the top of the left hand column. Otherwise your only option will be to click on every individual year!

Language Limits


"cancer gene therapy":de ANDenglish:la

Excluding Duplicate Medline Records

Embase includes Medline records from 1996 onwards. However if you have already searched PubMed, you may wish to exclude Medline results from your search in Embase

To limit your search to records unique to Embase add the following limit to your search

 AND [embase]/lim

This will include records for articles indexed by BOTH Embase and Medline, but exclude articles indexed only for Medline

NOT [medline]/lim

This will exclude ALL Medline records (including articles indexed by BOTH Embase and Medline)

Saving Searches

  • Login (You will need to register to save searches and to set up email alerts.)
  • When you have performed the search, click in the checkbox on the left in your Session Results.
  • Click Save. The dialog box which now opens, prompts you to select a folder in which to save your search.
  • You can save searches in any folder other than the Root Folder. I’d suggest you create a new folder called Saved Searches, and keep all subsequent saved searches there.
  • Give a name to your search
  • Click on the name of the folder to which you want to save your search.

More detailed help on saving searches is available from Elsevier.

Shared Search Folder

Saving a search in this folder allows other users to see it, as all searches in this folder may be viewed by everyone within the specified IP range for your institution. All Embase users may save searches here, if they would like to share with others in their institution. All searches may be viewed by all users in the same institution, but only the originator of the search may delete or make changes to the search. Sub-folders may be added to the main Shared Searches folder.

Email Alerts

You can set email alerts either from Session Results or from Saved Search pages.

  • Login (You will need to register to save searches and to set up email alerts.)
  • From the Session Results page, select the search you want to set as an alert and click the envelope icon. It will appear to the right of the screen near your search result count
  • The Set email alert pop-up box opens, prompting you to assign a subject (a name for the alert) and to specify email addresses to which it should be sent.

  • Click the drop-down frequency menu to choose from the following options:

every day, every week, every month, every two months, every three months, every six months and every year.
For weekly alerts you can choose the day of the week you want the alert to be sent.
For monthly alerts you can choose the day of the month you want the alert to be sent.

  • Type in the name of the alert.
  • Enter the email address to which the alert is to be sent, for multiple email addresses use ";" as a separator. This information can be edited at any time in Alert Details text box.
  • There are two options for email alert format: html and plain text. Select your preferred email format by clicking the radio button.
  • Choose the citation format option: Citations Only, Citations and Index Terms, Citations and Abstracts, Citations Abstracts and Index Terms, or Full record.

For Citations Only format, the limit is 500 records. If your search has produced more than 500 records, you may following a link to view all results in Embase.
If you select Citations and Abstract format, the first 25 results will be sent by email and you may follow the link provided to see the remaining records in Embase.

  • Choose whether you want to include articles in press or in process in your alert

Exporting Results to EndNote

At the Session Results screen, select the result set you want, and click on View Results

  • Select individual references or multiple results using radio buttons after Selected 
  • Click the Export option in the blue bar above the list of results
  • Choose Export format - RIS format (Reference Manager, ProCite, EndNote)
  • Click on Export  - at the bottom of the export format box
  • At the Ready for download screen - click on Download


Advantages of using Scopus:

  • Includes PubMed/Medline, most but not all Embase content plus more.
  • Has useful ‘Cited by' links.
  • ‘View at Publisher' (when available) links are next to each record to easily access the full text. There is also a ‘Find Fulltext' button next to each record to help find the full text of the article.
  • Reference lists in a record are hyperlinked.
  • Allows proximity searching eg PRE/ and N/
  • Has links to patents and data sets (on top right menu bar of serch results)

Search traps:

  • There is no mapping to MeSH or other subject headings eg Emtree. It is not possible to search directly for MeSH terms in Scopus, as it is in Medline (Ovid) and PubMed, although it is possible to search for MeSH terms as keywords, ie as words that appear in the keywords section of a record.
  • Limits are minimal. There is not the extensive range of limits available in PubMed, Medline (Ovid) and Embase.

If I have access to Scopus, do I need Embase?
'Scopus includes most, but not all, Embase content, as well as the Embase index terms. Scopus searches focus on abstracts and citations, while a search in Embase provides additional insights as a result of the structured full-text indexing of content.

Since Scopus does not use Emtree to facilitate synonym mapping and hierarchical searches, it may retrieve significantly fewer results than Embase. For example, a Scopus search on "heart attack" misses records mentioning "myocardial infarction" or indexed using the Emtree term "heart infarction".

In addition, Embase subheadings are not available on Scopus, so searches cannot be focused in the same way. For example, it is not possible to limit drug searches to records focusing on adverse effects.'
Source: https://www.elsevier.com/solutions/embase-biomedical-research/learn-and-support

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