An article with four authors was published in journal A. The same article with a slight change in the title and one additional author, was published three months later in journal B. The authors had submitted the article to both journals at the same time.
The number of study subjects in the two articles were the same, with a very slight difference in the wordings of the objective of the study. The first article focused on one outcome whereas the second article extracted the results on two aspects. The results were similar and the discussion was focused on the two different results obtained. This caused a large amount of overlapping of the text in both articles. It was apparent that it was one study divided into two articles with similar outcomes.
The author had submitted a disclaimer to journal B stating that the article was part of their PhD thesis. This statement was not submitted to journal A. Also it was not declared to either journal that the two articles had been extracted from a one thesis and published in two journals. On questioning the author, the reply was that they had included in the disclaimer that the article was derived from the PhD thesis.
The wordings of all sections of the article have major overlap which could not have been detected by either journal on submission, as the article was not available on either journal’s website at that time.
Questions for COPE Council
- Is it ethical to submit a number of articles derived from a PhD thesis on different aspects to various journals, and not to declare that similar articles have been extracted and sent to two journals?
- Does this amount to salami slicing or duplicate publication?
- Should journal B retract the article from its website as it published the research after the first publication in journal A?
Advice on this case is from a small number of COPE Council Members. Most cases on the COPE website are presented to the COPE Forum where advice is offered by a wider group of COPE Members and COPE Council Members. Advice on individual cases is not formal COPE guidance.
While it is possible to ethically derive multiple articles from a PhD thesis, this appears to be a case of redundant/duplicate publication (it is beyond text recycling because of the overlapping data). Thus according to the COPE flowchart on suspected redundant publication in a published article, journal B should "Consider publishing a statement of redundant publication or retraction [and] inform the editor of other journal involved".
It is a concern that the authors appeared to have submitted the two articles at the same time as independent works, when clearly they are, at best, interlinked. The editor might like to look at intent and perhaps have a discussion with the author to get clarification. A correction could be added to the second paper to indicate that it is linked to the previous paper. Retraction would only be appropriate if there was intent to slice the data or if there is major overlap in the results in papers from journal A and B and if the first paper is not cited.
If the editor thinks that the corresponding author may be inexperienced, they may wish to use this as a teaching opportunity about expected future behaviour. As examples, the author: (1) should have disclosed the PhD thesis to both journals A and B; and (2) should have cited journal A in the journal B article.
The editor should look at the dates of when the author either transferred copyright or granted a licence to publish (irrespective of which journal published first) to journal A and journal B. If this occurred first for journal B, then the article in journal A is the one that should be subject to a correction or retraction.
Journals A and B should review their author guidelines to ensure they have sufficient policies in place on redundant publication.