Research Guides: AMA Citation Style 11th Edition Guide: Clinical Trial Registries

Citing Trial Registries

General Trial Registry Format

Author/Group	Title	Registry Name ID	Identifier	Date Posted/Update	Date accessed	URL
Author AA, Author BB.	Title of trial.	Registry name identifier:	XXX###.	Updated Month Day, Year.	Accessed Month Day, Year.	xxx.xxx.gov
Group Name.	Title of trial.	Registry name identifier:	XXX###.	Posted Month Day, Year.	Accessed Month Day, Year.	xxx.xxx.xx

Trial Registry Specific Notes:

Include the Trial Registry identifier after the Registry name as shown in the examples
Common registries include: ClinicalTrials.gov (US), anzctr.org.au (Australia and New Zealand), isrctn.org (UK), trialregister.nl (the Netherlands), umin.ac.jp/ct (Japan), and EU Clinical Trials Register/ EudraCT (Europe)
If there is not an author or group associated with the trial, you can start the reference with the title of the trial (like example 2).

Examples:

General example:

1. Author AA. Title of trial. ClinicalTrials.gov identifier: NCT123456. Updated April 1, 2021. Accessed November 2, 2021. xxx.xxx.gov

Specific Example:

2. Evaluation of phage therapy for the treatment of Escherichia coli and Pseudomonas aeruginosa wound infections in burned patients (PHAGOBURN). ClinicalTrials.gov identifier: NCT02116010. Updated July 23, 2015. Accessed October 13, 2016. https://www.clinicaltrials.gov/ct2/show/NCT02116010

3. Rizzardini G. Clinical Study To Evaluate The Performance And Safety Of Favipiravir in COVID-19. ClinicalTrials.gov identifier: NCT04336904. Updated April 8, 2020. Accessed June 15, 2020. https://www.clinicaltrials.gov/ct2/show/NCT04336904

4.German Cancer Research Center. Use of acetylsalicylic acid (ASA) for enhanced early detection of colorectal neoplasms. EudraCT Identifier: 2011-005603-32/DE. Posted May 30, 2012. Accessed November 2, 2019. https://www.clinicaltrialsregister.eu/ctr-search/trial/2011-005603-32/DE