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Embase on Ovid – Database Size and Shape (docz.dz)

How to use the database command 'docz.dz.' and the Status (ST) field to identify the constituent parts of Embase on Ovid and show their relative sizes.

Embase

Ovid Training Team

2025-03-12

39 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

This Learning Pathway series of training modules draws upon the content and teaching approaches in and behind the learning resource OvidGO! (2). Constructed around a selection of focused searches, the training programme has been designed to achieve the following two objectives,

  1. to introduce the database, Embase on Ovid, drawing upon where helpful, parallels and comparisons with Ovid MEDLINE,
  2. to discuss, demonstrate and practice the key features and functionality of the database Embase on Ovid. 

(1) Reference for the above is the Embase Indexing Guide 2024.
(2). See https://tools.ovid.com/ovidgo/       

The docz.dz Command
Entered at the command line in any of Embase on Ovid’s search modes, you can use the docz.dz command on any database on Ovid to establish the number of records in the resource. By combining this database command with database fields such as Status (ST) or Publication Type (PT), either individually or in combination, it becomes possible to imagine the ‘shape’ of the database. By this is meant the database’s structure, its composition in terms of database fields, its indexing processes, controlled vocabulary and limits options. These are database properties you need to know, be aware of  and consider when designing search strategies as they may have a material impact on your searches, their construction, execution and rendered outcomes.    

This focused search, launched on Embase on Ovid, will provide you with information on the total number of records in the database at the time the search is run. In other words, the database ‘size’. Then by separating out the database records according to their editorial status, that is by using the Status (ST) field, it is possible to view the database in terms of its constituent parts. This is what is meant here by the ‘shape’ of the database. This perspective, indeed the precise information, can also be used when constructing searches to swiftly narrow down to a specific document or publication type. For example, to conference materials or only Embase articles.

Points to note:

  • Abstracting and Indexing (A&I) databases are the most reliable and best verifiable sources of scientific information and are indispensable for systematic literature searching.
  • Generally speaking, A&I databases are composed of structured and searchable bibliographic records, many of which now increasingly also link out to their full-text original documents.
  • Composed of tens of millions of bibliographic records, these information repositories are diverse, highly structured, regularly updated and thereby relentlessly dynamic.
  • Their large size and relentless dynamism remains opaque to many users and as a result can be potentially problematic to investigating researchers and healthcare professionals.

Instructions:

  1. Logon to Ovid, select Embase <1974 to Present>, select the Advanced Search / Keyword mode.
  2. Enter the search lines for this focused search as listed below.
  3. Alternatively, having not yet logged on,  <Click here> to run this focused search above in Ovid.

docz.dz.
limit 1 to article-in-press status
limit 1 to conference abstract status
limit 1 to embase status
limit 1 to in-process status
limit 1 to in-data-review
limit 1 to in-process
limit 1 to pubmed-not-medline
limit 1 to "pubmed/medline"
limit 1 to publisher
limit 1 to "preprint (unpublished, non-peer reviewed)"
2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11

Questions:

  1. What proportion of the database are conference materials?
  2. List at least two sources of preprint servers
  3. Could you conduct a thesaurus search on the PubMed-not-MEDLINE NLM records?

 

Search Stategy

docz.dz.
limit 1 to article-in-press status
limit 1 to conference abstract status
limit 1 to embase status
limit 1 to in-process status
limit 1 to in-data-review
limit 1 to in-process
limit 1 to pubmed-not-medline
limit 1 to "pubmed/medline"
limit 1 to publisher
limit 1 to "preprint (unpublished, non-peer reviewed)"
2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11

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 – Database Size and Shape (docz.dz) [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=102