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Embase on Ovid – Multiple Databases, Single Session

How to launch a search strategy, that utilising database specific thesauri and limits, nevertheslss functions across multiple databases, and does so in one database session. (Romper Search).

Databases – Combinations

Ovid Training Team

2025-03-12

53 visits

Background

Embase, produced by the academic publishing and information analytics company Elsevier B.V., is one of the largest and most comprehensive Abstracting and Indexing (A&I) database for peer-reviewed biomedical information. The Embase database covers all disciplines of medical and biomedical science as well as Allied Health subjects.

Embase on Ovid – Facts and Figures (1)

  • A bibliographic database, Embase is made up of over 41 million database records.
  • Over 1.7 million records are added each year.
  • Database records are indexed using Emtree, the Elsevier Life Science Thesaurus.
  • Conference materials, currently at over 5 million records, have been included since 2009.
  • Preprint records, from several sources, have been included since November 2021.
  • All database records are indexed using automated means and procedures.
  • Records pertaining to diseases, drugs and devices undergo further manual indexing.

Training Session Programme

Questions:

  1. Are there benefits to exploding the Emtree term ‘palbociclib’?
  2. Are there benefits to exploding the Emtree term ‘neutropenia’?
  3. How could you focus the search without going back to the Emtree thesaurus?

This focused search launches a search strategy that operates across two databases, namely Embase on Ovid and Ovid MEDLINE - at the same time. The search is investigating covid vaccines and their potential side effects. The difficulty is that both of the constituent topics, i.e. covid vaccines and side effects, are treated differently by the controlled vocabularies of the target databases, Embase on Ovid and Ovid MEDLINE. The ‘Romper Search’, enabled on the Ovid platform by deploying the USE command to change databases, provides a means of searching two or more databases in a single session while still making use of the thesaurus and limits selection, specific to each of the databases. The instructions below plus the accompanying supplemental documentation describe in detail how to build such a search. Once practiced and familiar with the construction of this type of search, you could save it in Ovid My Workspace as a model example, for re-use and further development.

Points to note:

  • The regulatory environment around drug and device safety usually requires that A&I databases be consulted individually.
  • Best practice guidelines around systematic literature searching also recommends searching in separate databases.
  • Embase on Ovid and Ovid MEDLINE are both available on the Ovid platform and can be searched individually or in combination.
  • When searching the databases in combination, search expressions employing the Title (TI) or Abstract (AB) fields, either separately or in combination, yield reliable results. As does Ovid’s Basic Search (NLP) mode. So too does Ovid’s .mp (Multi-Purpose) search function. This however needs qualification as the set of fields searched across in each case differs between databases.  
  • However, where the search strategy wants to avail of the specific thesaurus qualities of the target databases and/or the database’s own selection of limits, problems of inaccurate term or terms translation or rendering may occur.
  • Named the ‘Romper Search’ Ovid has developed a search option that, utilizing the USE command, facilitates a single search across two or more databases in one session enabling searchers to avail of the databases’ specific construction, their database specific controlled vocabulary and sets of limits.

Instructions:

  1. Logon to Ovid, select firstly Ovid MEDLINE and the Advanced Search / Keyword mode.
  2.  Enter the search expressions for this database.
  3. Park your Ovid MEDLINE results in the search history using the database segment abbreviation ‘medall’.
  4. While still in the Ovid session, next select Embase and remain in the Advanced Search / Keyword mode.
  5. Enter the search expressions for this database.   
  6. Park your Embase results in the search history using the database segment abbreviation ‘oemezd’.
  7. Now re-run your parked searches through Ovid MEDLINE and Embase in the one session.
  8. Combine your parked searches using the OR operator.
  9. Add limits or impose additional search criteria, e.g. deduplication, as necessary.
  10. Alternatively, having not yet logged on,  <Click here> to run this focused search above in Ovid.

COVID-19 Vaccines/
"Drug-Related Side Effects and Adverse Reactions"/
1 and 2
3 use medall
SARS-CoV-2 vaccine/
adverse drug reaction/
5 and 6
7 use oemezd
4 or 8
remove duplicates from 9

Questions:

  1. How could you expand upon the search using free terms?
  2. Would the limit Publication Type [PT] cover clinical trials for both databases?
  3. How could you identify the duplicates within Embase only?

 

Search Stategy

COVID-19 Vaccines/
"Drug-Related Side Effects and Adverse Reactions"/
1 and 2
3 use medall [1. Park above in Ovid MEDLINE, 2. Continue in Embase]
SARS-CoV-2 vaccine/
adverse drug reaction/
5 and 6
7 use oemezd [1. Park in Embase, 2. Re-run in both databases]
4 or 8 [Combine Ovid MEDLINE & Embase results]
remove duplicates from 9

Launch Search

Reviewers

Primary: Michael Fanning

Secondary: Charlotte Viken

Review Date: 2025-03-12

Expiry Date: 2026-03-10

Original search produced by:

Ovid Training Team

Citation:

OvidGO! Portal. Focused Searches: Embase on Ovid – Multiple Databases, Single Session [Internet]. London (UK): Ovid Training Team (Editors); 2025 [updated 2 March 2024; cited 10 March 2025]. Available from: https://tools.ovid.com/ovidgo/searches/view.php?id=108