The authors carried out a randomised single blind controlled trial on the effects of a pain relieving intervention in pregnant women for pelvic girdle pain. Participants were recruited between 2000 and 2002 and the results were published in 2005. The trial had not been registered at the time.
The authors now want to publish the adverse effects of the same intervention during pregnancy and delivery. The data in the new manuscript were gathered from 2000 to 2002 and is from the same study population. On submission of the manuscript we enquired about a trial registration number and the authors indicated that the trial had not been registered. Their interpretation of the International Committee of Medical Journals Editors (ICMJE) statement is that this trial does not need a number because enrolment was completed before 2005.
Given that the authors wish to publish data from the original trial after 2005, should we insist on a trial registration number?
The ICMJE statement states the following for trials that began before 1 July 2005:
Investigators should register trials that began enrolling patients any time before July 1, 2005 as soon as possible if they wish to submit them to a journal that follows the ICMJE policy. While the ICMJE hoped that all such trials would be registered by September 13, 2005, the committee understands that the policy statement was not entirely clear. Thus, ICMJE journals will consider trials that began before July 1, 2005 that were not registered prior to September 13, 2005. However, beginning on September 13, 2005, ICMJE journals will consider such trials only if they were adequately registered before journal submission. The ICMJE journals will accept “retrospective registration” of trials that began before July 1, 2005 (retrospective meaning registration occurs after patient enrolment begins).
The Forum questioned whether this was a case of salami slicing and asked why these data had not been published in the original paper. All agreed that there was no point in registering the trial at this point. The editor should not insist on trial registration as it may cause more confusion as it might then appear to future enquirers that there were two trials when in fact all the data were from the same trial. All agreed that it should be made clear that the data are from the old trial and that this is a follow-up of the original study. It was suggested that the editor could write to the authors and ask them why they did not publish these data in the original paper.
June 2008
We did not insist on a trial registration number for this manuscript, but did insist the authors clearly indicate that they are reporting additional data from a published randomised controlled trial. We did ask them why they delayed publishing these data for so long, but are still waiting for a response to this question.
August 2008
The authors clarified, in the manuscript, the link with their previous publication so we went ahead and published this the paper at the end of June.