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ISRCTN to be Added to MEDLINE®/PubMed® Data

Knecht LS. ISRCTN to be Added to MEDLINE®/PubMed® Data. NLM Tech Bull. 2006 Mar-Apr;(349):e9.

April 27, 2006 [posted]
June 06, 2006 [Editor's note added]

Starting in May 2006, the National Library of Medicine® (NLM) will be including the International Standard Randomised Controlled Trial Number (ISRCTN) in MEDLINE/PubMed records, when that information appears in the original publication. For information about the ISRCTN, please see the ISRCTN Register. For more background information please see the International Committee of Medical Journal Editors (ICMJE) Web site for their editorial and updates on the topic of registering clinical trials before publication of the results.

The ISRCTN data will appear in PubMed in the Secondary Source ID list in the Citation display, in the SI field of the MEDLINE tagged display, and in the DataBankList elements of the XML display. The general display format for the data is: an alphabetic label of ISRCTN followed by a slash and then a 14-digit alphanumeric string starting with ISRCTN followed by eight numbers. An example in the Citation format display would be:

Secondary Source ID:

  • ISRCTN/ISRCTN46889466

If there are multiple ISRCTN numbers mentioned in one journal article, all will be added to the MEDLINE/PubMed record.

In PubMed, the data will be searchable using the [si] search tag; each of the pieces or the entire string is searchable, e.g.:

isrctn46889466 [si]
isrctn [si]
isrctn/isrctn46889466 [si]

Use "isrctn [si]" to retrieve all citations to articles listing trial registration in the ISRCTN Register regardless of which particular trial is involved.

In addition, on the Citation display, ISRCTN numbers will link directly to the trial information on the ISRCTN Register Web site.

NLM also includes the ClinicalTrials.gov identifier number in its journal citations.

[Editor's Note: NLM has edited citations created before May 2006 if an ISRCTN number appeared in the citation's article title or abstract to create a Secondary Source ID (SI) occurrence. The earliest known citation has a publication date of 2001.]