In 2016, with coauthors Arturo Casadevall and Ferric Fang, I published a study on 20,000 biomedical papers with photographic images, in which we found an average of 4% to contain inappropriately duplicated images.
Not surprisingly, we found that percentage to vary per journal. Some of the 40 journals we investigated had much higher percentages of image duplicates than others.
Three journals in our study, published by Hindawi and Spandidos, had the highest percentage of duplicated images in our study (top of the graph above), i.e. 10.4 -12.4%.
Scanning Oncotarget papers
One journal that was not included in our dataset but that appeared to have a higher percentage of duplicated images was Oncotarget, an Open Access journal. I therefore decided to do a targeted (pun intended) study on the percentage of problematic papers in Oncotarget. I also wanted to see if this percentage had been changing over the years.
In the past months, I scanned a total of 675 Oncotarget papers from 2015-2019, an average of 135 papers (range: 83-167) per publication year. Only papers with photographic or flow cytometry images were included in this count. Papers with only line graphs or tables were not scanned.
Among these 675 papers, I found a total of 96 papers with image issues (14.2%). Here is the graph of the percentage, plotted per year:
In August, as I was doing this scan, I wrote to Oncotarget to ask them what their thoughts were about this high percentage of duplicated images in their journal. The Editorial Office replied:
We share the same principles of scientific integrity, and we seek to do everything we can to ensure that scientists to not publish problematic images. (…) We are addressing the issue of problematic images in different ways. First, we have started using an image forensic service provided by one of the largest and most reputable companies in the industry. Right now, after making all the necessary technical arrangements, we are extending this service to make sure all papers pass through image forensics. Second, we investigate all reports of irregularity that we receive.Oncotarget Editorial office response (per email, August 2019)
In a later reply, Oncotarget wrote:
We have our own database containing information about all questionable papers. The authors and some institutions (there are some institutions with higher rate of the questionable papers) from that database are “red flagged” in the submission system. New submissions are checked against the database during quality control.Oncotarget Editorial office response (per email; August 2019)
Our Assistant Editors are often able to catch previously published images during quality control. Here we are, of course, depending on the skill of our Editors, but this measure definitely helps us to catch duplications.
Peer-reviewers are pretty efficient in catching questionable images. To help them, we have contracted one of the most reputable companies in the industry to provide image forensic analyses. Moreover, after completing the necessary technical and financial arrangements, we are extending this service to ensure that all submitted papers pass through image forensics and that the results are available to the reviewers and authors.
Indeed, from the graph above, it looks as if the percentage of problematic papers in Oncotarget issues is indeed decreasing, starting in 2018. At 9.7%, it is still higher than that in many other journals, though. I encourage the journal therefore to increase their editorial screening of images in submitted papers
Drop in Oncotarget papers after being dropped from science paper indexes
Of note, the Oncotarget issues from late 2018 and 2019 contained significantly fewer research papers than in the previous years. Oncotarget publishes a new issue every 4-7 days. The interval was first 7 days in 2015-August 2017, but was shortened to 4 days from Sept 2017-now, possibly because the journal was gaining in popularity. The first 2 issues of 2019 contained fewer papers than the ones from previous years.
Here is a graph of the number of research papers per issue. Note that I only included the first 2 issues of each year, so the ones published in January, and that the numbers only include papers with photographic images.
There is a sudden drop in the number of research papers in the January 2019 issues compared to the January issues of previous years. This sudden drop in papers might be linked to recent decisions of several scientific index services to no longer include Oncotarget.
In the fall of 2017 Medline stopped including new Oncotarget papers in their database (see coverage by Retraction Watch). In 2018, the journal was dropped from Clarivate Analytics’ Journal Citation Reports and the Science Citation Index Expanded (SCIE) (as per LetPub and Wikipedia). However, new Oncotarget issues remain available on NCBI’s Pubmed, PMC, and SCOPUS.
Oncotarget’s exclusion from scientific paper databases might have been caused by the inclusion of the journal on Beall’s list of predatory journals (which does no longer exist). In a January 2018 editorial Oncotarget’s Editor in Chief Mikhail Blagosklonny wrote:
We remain hopeful that the decision will be reversed. Despite these attacks, Oncotarget has continued to serve as a well-recognized and respected international journal, and has continued to flourish. (…)
For thousands of years libraries served science and scientists. Indexes were created to disseminate information, not to suppress it. For the first time in history, in response to rapid technological progress, librarians are suppressing science and refusing to serve science. Of course, this not true of all librarians. The new generation of librarians resist Beall’ s ideas, including Beall’s supervisor, whose recent article should be read by everyone.
We, the scientists, should change the situation and change the policies of Indexes such as Clarivate’s Web of Science and MEDLINE, and make indexes work for us. Otherwise, why should these organizations exist?Librarians against scientists: Oncotarget’s Lesson – Mikhail V. Blagosklonny, Oncotarget 2018, doi: 10.18632/oncotarget.24272
The loss of the inclusion of Oncotarget in these scientific indexes might have made the journal less attractive for researchers to publish in, and might have caused the number of submissions to have dropped significantly in 2018. With their high percentage of duplicated images, although dropping, they clearly still have a long way to regain the trust of scientists and science indexing services.