Box 111 The International Standard Randomized Controlled Trial Number ISRCTN

For researchers conducting systematic reviews, difficulties can arise in determining publications that refer to the same trial, as, for example, authors differ, or numbers included in analyses vary between publications. Similar difficulties may occur where a trial is included in more than one register. Such problems could lead to double counting; including trials more than once in a systematic review, and consequently such trials receiving undue weight in any quantitative analyses. An internationally accepted, uniform system of unique trial identifiers would therefore be extremely useful to reviewers, making it immediately apparent where multiple reports or register entries refer to the same trial.

Although the concepts underpinning the ISRCTN scheme are not new, it represents the first time unique identifiers have been assigned to RCTs on an international basis. The ISRCTN scheme was launched in 2001 concentrating initially on UK cancer trials and on other UK MRC funded trials. However, funding organizations and individual trialists worldwide will be invited to participate in the scheme. The scheme, overseen by an independent advisory group, is managed by Current Controlled Trials, who are also responsible for the metaRegister of Controlled Trials (mRCT).

♦ The ISRCTN is an 8-digit number that is assigned to an RCT. It is used to uniquely identify a trial and remains with it through its duration, from funding, through the entirety of the trial process to eventual publication.

♦ The ISRCTN should be included in trial protocols, documentation and publications and presentations. It should also be recorded within online bibliographic databases and trial registers.

♦ The ISRCTN is issued to trials by the trial sponsor. Where sponsors do not administer ISRCTNs for the trials that they support, an ISRCTN can be obtained by the principal investigator on registering the trial with the metaRegister.

The ISRCTN should, in future, promote widespread prospective registration and provide a more complete public record of RCTs, through the mRCT and contributing registers. The numbering system should facilitate identification of trials that appear on more than one register, and so help to prevent 'double-counting' of trials. As the scheme progresses, it is envisaged that journal editors will require ISRCTNs for all trials submitted for publication. This should further facilitate trial searching and allow reviewers to more easily identify duplicate publications of individual trials.

0 0

Post a comment