How seriously are journals taking duplicated work that they publish? That was the question Mario Malički and colleagues set out to answer six years ago. And last month, they published their findings in Biochemia Medica.
The upshot? Journals have a lot of work to do.
Since we’re often asked why duplication is a problem, we’ll quote from the new paper: Duplication “can inflate an author’s or journal’s prestige, but wastes time and resources of readers, peer reviewers, and publishers. Duplication of data can also lead to biased estimates of efficacy or safety of treatments and products in meta-analyses of health interventions, as the same data which is calculated twice exaggerates the accuracy of the analysis, and leaves an impression that more patients were involved in testing a drug. Not referencing the origin or the overlap of the data, can therefore be considered akin to fabrication, as it implies the data or information is new, when in fact it is not.”
We asked Malički to answer a few questions about the new study.
Retraction Watch (RW): You note that MEDLINE, part of the U.S. National Library of Medicine, tags duplicate articles “whenever substantial overlap between two or more articles is discovered during indexing, irrespective of an authorized notification.” That seems unusual among indexers, yes?
Mario Malički (MM): Yes, to the best of our knowledge, NLM indexers are the only one doing this among all the large bibliographic databases. NLM has confirmed this practice to us, but not the specifics surrounding it (e.g. are indexers trained to do this, is more than one indexer needed before such a tag goes online, or are there any other control mechanism when an indexer tags articles as duplicates). As our results indicated, the indexers made mistakes in 35% of cases; nevertheless, we fully support the NLM practice, as thanks to their tagging we were both able to conduct the study and engage editors in correcting the records. It would be ideal if they would inform the journals when an article is tagged, but this goes beyond their practice.
RW: This study took five years. Explain the various steps.
MM: There are several reasons why it took this long. Frist, this was always a side project I was doing alongside my PhD studies. Second, after I presented our initial results at the 2013 International Congress on Peer Review in Biomedical Publication in Chicago, we were recommended to contact the editors, as well as to explore the citation rates of the duplicates and originals, which we initially did not plan to do. We also met with NLM at the conference and shared the cases we thought were their mistakes, most of which they corrected until end of 2014. So, we contacted the editors in 2015, send reminders, and then waited for 2 years to see whether they published notices or retracted the duplications. As we discovered that some tags were errors of the NLM, we then decided, for all those cases we did not get a response from journals, to obtain the full text of the articles and compare them manually – to confirm if indeed they were duplicates or not. In quite a few cases, it turned out they were not. I then got my postdoc position in Amsterdam, so the final check and manuscript update was done in 2018.
RW: You differentiate duplications that were “due to the publishers’ actions, most commonly publication of the same article in two different issues of the same journal,” from those “occurring due to authors’ actions…most commonly due to submission of the same manuscript to two different journals.” Were the latter cases likely due to publisher error?
MM: No, they were cases when authors misused the publishers’ trust and did not inform them of publications they already had or submitted. We used the term “authors actions” rather than misconduct because self-plagiarism is not everywhere defined legally as misconduct. But we definitely see it as detrimental research practice.
RW: What were your main findings?
MM: Our main finding is that duplicate publications are not addressed – in our study only 54 % (n=194 of 359) of duplicates were addressed by journals and only 9% (n=33) retracted, although they should all have been retracted according to editorial standards (e.g. COPE). My personal impression is that duplicate publications are of low interest to the publishers and the media. They are not as “exciting” as cases of fabrication, falsification or plagiarism of data or ideas, but rather an indication of the flaws in the system – the inability to detect that such a publication already exists. If I compare duplicate publications to simultaneous publications of practice guidelines in several journals, which is common practice, it seems very easy to correct duplications – instead of retracting them – publish a notice or second version which clearly states this publication was first published elsewhere. The interesting question is, for those duplicates that were the results of authors intentionally submitting them to two or more different journals – did these authors use those “different” publications to boost their CVs or to obtain grants or funding? In 57% of cases of duplications due to authors actions, there were changes in the number or order of authors, so it is likely the authors had specific gains in mind – but this was not something we could investigate in this study.
RW: What would you conclude from these findings, about MEDLINE duplication notices, and about journals’ willingness to take action about potential duplications?
MM: I would like to thank both the NLM and the editors/journals that responded to our queries and did something to correct the records. Unfortunately, the process is too slow. Everyone seems to be unprepared to deal with these issues, and after notifications, investigations took too long – as if it is really hard work to compare two texts and see if they are the same. As for the MEDLINE notices, I applaud NLM for what they tried to do, and hope their next step will be even bolder – to include highly visible descriptions tags in search engines (perhaps even as an addition to the titles of papers) and when citations are exported in any format – to clearly alert users that they are dealing with papers that are duplicates. Such a thing would be welcome, not just for duplications, but also for retractions, and possibly even for simultaneous publications.
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