Citing databases and study registers
The preferred format for the following databases is all upper-case letters: MEDLINE, CENTRAL, OLDMEDLINE, and CINAHL (not CINHAL). A number of databases use a mixture of lower-case and upper-case letters, for example, Embase (not EMBASE), PsycLIT (not PsychLIT) and PsycINFO (not PsychINFO).
Some Cochrane entities maintain a register of studies in their area of expertise. The name of the register may vary but will follow one of the following formats: [Entity name] Specialized Register; [Entity name] Specialised Register; or [Entity name] Trials Register.
The databases and trials registers and other resources that are searched for studies for a Cochrane review are listed in the ‘Search methods for identification of studies’ (in the Methods section). The databases and registers must be listed in the following order: [Cochrane Group name] Specialised Register (or Specialized Register or Trials Register), CENTRAL, MEDLINE, Embase, and any other databases.
In the Abstract, brief text may be used to describe the sources searched, e.g. ‘We used CENTRAL, MEDLINE, xx other databases and xx trials registers, together with reference checking, citation searching and contact with study authors to identify studies that are included in the review. The latest search date was x/xx.' (Add key limitations, if present).
In the Search Methods section, the date of the latest search (day month year) should be provided along with the issue or version number (as appropriate) of each database, e.g. CENTRAL (year, issue number). The date of inception of the database should be given where known. Database names should include the platform or provider name, and websites should include the full name and URL.
The date range (for databases) or search date (for study registers) of each search must be listed with each database; for example, CENTRAL (year, issue number), and for most other databases, such as MEDLINE, it should be in the form 'MEDLINE (year to day month year)'.
Example:
- the Cochrane Hepato-Biliary Group Controlled Trials Register via the Cochrane Register of Studies Web (10 June 2026)
- the Cochrane Central Register of Controlled Trials (CENTRAL; 2026, Issue 5) in the Cochrane Library (searched 10 June 2026)
- MEDLINE ALL Ovid (1946 to 10 June 2026)
- Embase Ovid (1974 to 10 June 2026)
- CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; 1982 to 10 June 2026);
- PsycINFO Ovid (from 1806 to 10 June 2026);
- AMED Ovid (Allied and Complementary Medicine; 1985 to 10 June 2026);
- LILACS (Latin American and Caribbean Health Science Information database; 1982 to 10 June 2026);
- Science Citation Index Expanded (1900 to 10 June 2026)
- Conference Proceedings Citation Index – Science (1990 to 10 June 2026).
- ISRCTN registry (www.isrctn.com; searched 10 June 2026);
- US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (www.clinicaltrials.gov; searched 10 June 2026);
- Australian New Zealand Clinical Trials Registry (www.anzctr.org.au; searched 10 June 2026);
- World Health Organization International Clinical Trials Registry Platform (apps.who.int/trialsearch; searched 10 June 2026);
- EU Clinical Trials Register (www.clinicaltrialsregister.eu; searched 10 June 2026).
Other formatting options for MEDLINE and Embase:
- MEDLINE Ovid (1946 to November week 3 2026)
- Embase Ovid (1974 to 2026 week 47)
Search terms
Search terms consist of text words (preferred spelling is two words, not 'textword') and indexing or controlled vocabulary terms. The preferred format for referring to the National Library of Medicine's controlled vocabulary used for indexing articles for MEDLINE (and PubMed) is MeSH (not MESH).
Focused review format: supplementary materials
The full line-by-line search strategies for each database (and other sources, if applicable) with search strings, database names, access platforms, search fields and other limitations/settings should be included in the Search strategy supplementary material (supplementary material 1).
