Duplicate Publication and Submission - Ethical and Legal Considerations

AMA Manual of Style - Stacy L. Christiansen, Cheryl Iverson 2020

Duplicate Publication and Submission
Ethical and Legal Considerations

Wasteful publication includes dividing the results in a single study into two or more papers (“salami science”); republishing the same material in successive papers (which need not have identical format and content); and blending data from one study with additional data to extract yet another paper that could not make its way on the second set of data alone (“meat extenders”).

Edward J. Huth, MD1

Duplicate publication is the simultaneous or subsequent reporting of essentially the same information, article, or major components of an article 2 or more times in 1 or more forms of media (either print or electronic format) by 1 or more of the same authors.2,3,4,5,6,7,8,9 Duplicate reporting includes duplicate submission and may apply to both published and unpublished works (eg, 1 or more manuscripts not yet published but under consideration by another or multiple journals). Other terms used to describe this practice include redundant, prior, repetitive, overlapping, related, multiple, dual, parallel, fragmented, and secondary publication.3,8,9 The term self-plagiarism is best avoided to describe duplication by the same author(s) given that plagiarism is a form of theft and authors cannot steal from themselves (see 5.4.2, Misappropriation: Plagiarism and Breaches of Confidentiality).

Duplicate submission or publication is not necessarily unethical, but failure to disclose the existence of duplicate articles, manuscripts, or other related material to editors and readers (covert duplication) is unethical and may represent a violation of copyright law. Moreover, reports of the same data in multiple articles waste publishing resources (ie, those of editors, reviewers, and readers as well as journal pages or space),1 pollute the literature with redundant information of dubious additional value, may result in double counting of data or inappropriate weighting of the results of a study and thereby distort the available evidence,2 cause problems for researchers and those who conduct systematic reviews and meta-analyses,10,11 and may damage the reputation of authors12 (see 5.3.1, Secondary Publication, for a discussion of legitimate secondary publication).

Duplicate publication usually involves 1 or more of the same authors, but the number of authors and order of authors may differ among the duplicate reports. Duplication occurs when there is substantial overlap in 1 or more elements of an article or manuscript. For reports of research, duplicative elements may include any or all of the following: the introduction, design, methods, samples or subsamples, data, outcomes, tables, graphics and illustrative material, discussion, or conclusions. Inclusion of the same or similar wording for Design and Methods sections in reports of follow-up studies or to describe samples or data sets in reports of secondary analyses is acceptable provided that the primary study is cited in the follow-up and secondary publications. Duplication also occurs in other types of articles (eg, reviews, case reports, opinion pieces, letters to the editor, and blog posts). Postpublication news summaries and brief summaries via social media are not typically considered duplicate publication in the context of scholarly publishing; citation of (or linking to) the primary article or reference in these summaries is recommended.

There is no widely accepted method of classifying the amount of acceptable overlap or duplication. Authors and editors often disagree on how to define and quantify duplication and whether duplicate articles are justified.13 Researchers in 2 studies of duplicate publication classified an article as duplicative of another if 10% or more of the content was identical or highly similar.7,14 Others have described levels and patterns of duplicate publication for research articles that emanate from 1 study, such as reporting identical samples and identical outcomes, identical samples and different outcomes, increasing or decreasing sample sizes and identical outcomes, and different subsamples from the same overall large study and different outcomes.12,15 Studies have also found that most duplicate articles are published within 1 year of the publication of the first report.12,16

A number of studies of the prevalence of duplicate publication in various fields, using the various levels and definitions of duplication noted in the above paragraph, have found that 1.4% to 28% of published articles were classified as duplicative of other articles.7,8,10,14,16,17,18,19,20,21,22,23 In addition, these studies reported that as many as 5% to 61% of duplicative articles did not include a citation or reference to the original or primary article (covert duplication).7,10,14,18,21,22

Following the recommendations of the International Committee of Medical Journal Editors (ICMJE),2 a policy that prohibits or discourages duplicate submission and publication does not preclude consideration of manuscripts that report on research that has been presented at a professional society or scientific meeting as abstracts or posters, orally, or in slides or other digital media. This policy applies whether the presentation is made in person or via webcast or an online meeting presentation. However, publication of complete manuscripts in proceedings of such meetings in print or online may preclude consideration for publication in a primary-source journal. The ICMJE cautions authors to “consider how dissemination of their findings outside of scientific presentations at meetings may diminish the priority journal editors assign to their work.”2

News reports that cover presentations of data at scheduled professional meetings would not necessarily violate this policy, but authors should avoid distributing copies of their complete manuscripts, tables, graphs, and illustrations during such meetings. Preliminary release of information directly to the news media, usually through press conferences or news releases, and dissemination of that information in news reports or social media should be considered by journal editors during the evaluation of a submitted manuscript and could jeopardize an author’s chances for publication in a primary-source journal.24 However, exceptions are made when a government health agency determines that there is an immediate public need for such information8,24 (see 5.13.1, Release of Information to the Public).

Manuscripts that are based on the same data or report analyses of the same data sets are acceptable when these are from different authors. The ICMJE recommends that such manuscripts be handled independently because they “may differ in their analytic methods, conclusions, or both.”2 Authors of reports of secondary analyses should cite the primary analysis and publication, clearly describe the database on which the analysis and report are based, and indicate any overlap in data. This information should also be summarized in the cover letter that accompanies the submitted manuscript. Editors should make decisions on these types of papers based on their editorial priorities and the strengths of the individual analyses and reports and, if all are relatively equal, perhaps give primacy to the manuscript submitted first or consider the merits if the secondary report is an important replication study.

Authors may also publish multiple articles using the same data from very large studies but addressing different questions. In these cases, authors should clearly cite previous related articles and should inform editors of any related manuscripts under consideration elsewhere or in preparation.

See Box 5.3-1 for examples of duplicate reports that may be acceptable and necessary.

Box 5.3-1. Duplicate Reports That May Be Acceptablea

Summaries or Abstracts of Findings Reported in Conference Proceedings

Editors do not discourage authors from presenting their findings at conferences or scientific meetings, but they recommend that authors refrain from distributing complete copies of their papers, which might later appear in some form of publication without their knowledge. Previous presentation(s) should be noted in submitted manuscripts (see 2.10, Manuscript Preparation for Submission and Publication, Acknowledgments [Article Information], Meeting Presentation).

News Media Reports of Authors’ Findings

Typically, editors do not discourage authors from reporting their findings at conferences covered by the news media, but they discourage authors from distributing their full papers, tables, or figures, which might later appear printed in a newspaper, a newsletter, or the news section of a magazine. Editors do not discourage authors from participating in interviews with the news media after a paper has been accepted but before it is published. However, authors should remind reporters that most journals have an embargo policy that prohibits media coverage of the manuscript under consideration and the article before it is published (see 5.13, Release of Information to the Public and Relations With the News Media).

Fragments or Sequential Reports of Studies

Editors make decisions about these types of duplicative research reports on a case-by-case basis. For all such papers, editors ask that authors properly reference previously reported parts of a study and send copies of these papers or articles along with their submitted manuscript.

Detailed Reports Previously Distributed to a Narrow Audience

The scope of this audience and the nature of distribution (eg, small print run, time-limited placement on closed website) would determine whether editors would publish a duplicative report. For all such papers, editors ask that authors properly reference all such previous publications and send copies of these along with their submitted manuscript.

Short Reports in Print and Longer, More Detailed Reports Online

Some journals publish shorter versions of articles in print and longer versions online. The existence of multiple versions of the same article should be made clear to readers and bibliographic databases.

Executive Summaries and Evidence Synopses

Concise overviews or summaries of large, detailed reports, documents, or guidelines or synopses of evidence-based analyses or systematic reviews that are regularly updated are handled on a case-by-case basis. For all such summaries, editors ask that authors properly reference the larger, more detailed report.

Reports From Government Documents or Reports in the Public Domain

Decisions regarding republication of government documents or other reports in the public domain are based on the importance of the message, priority for the journal’s readers, and availability of the information. For example, a journal may publish reports from the Centers for Disease Control and Prevention that were initially published in the Morbidity and Mortality Weekly Report, or a journal may publish a report from a governmental agency after the public release of a draft report (eg, from the US Preventive Services Task Force) or a required data release (eg, from the US Security and Exchange Commission). The existence of multiple versions of the same report should be made clear to readers.

Translations of Reports in Another Language

Translations are usually acceptable as long as they give proper attribution to the original publication (see 5.3.1, Secondary Publication). Translations should be faithful to the original, should not introduce any new content or authors, and should not omit any content or authors. Translators should be acknowledged.

Announcements Shared Across Journals

Simultaneous publication of editorial announcements, policies, or reporting guidelines are acceptable provided that indication of the nature of the simultaneous publication is indicated (see 5.3.1, Secondary Publication).

Reports Based on the Same Data or Data Sets

Reports from different authors that are based on the same data or analyses of the same data sets are acceptable because they may differ in their methods, analysis, interpretation, or conclusions.

For each of these cases, a query to the editorial office is recommended, asking whether any previous publication or release of information jeopardizes a chance for subsequent publication in a specific journal.

a Updated from Blancett et al.7

5.3.1 Secondary Publication.

Secondary publication is the subsequent republication, or simultaneous publication (sometimes called dual or parallel publication), of an article in 2 or more journals (in the same or another language) by mutual consent of the journal editors. Secondary publication can be beneficial. For example, the editors of an English-language journal and a non—English-language journal may agree to secondary publication in translated form for the benefit of audiences who speak different languages.

The ICMJE approves secondary publication if all the following conditions are met2:

1.The authors have received approval from the editors of both journals (the editor concerned with secondary publication must have access to the primary version).

2.The priority of the primary publication is respected by a publication interval negotiated by both editors with the authors.

3.The paper for secondary publication is intended for a different group of readers; an abbreviated version could be sufficient.

4.The secondary version faithfully reflects the authors, data, and interpretations of the primary version.

5.The secondary version informs readers, peers, and documenting agencies that the paper has been published in whole or in part elsewhere−for example, with a note that might read: “This article is based on a study first reported in the [journal title, with full reference]”−and the secondary version cites the primary reference.

6.The title of the secondary publication should indicate that it is a secondary publication (complete or abridged republication or translation) of a primary publication. Of note, the NLM does not consider translations to be “republications” and does not cite or index them when the original article was published in a journal that is indexed in MEDLINE.

MEDLINE includes a language field for identifying multiple languages in which an article, or its abstract, is published. Thus, when the same journal simultaneously publishes an article, or its abstract, in multiple languages, the MEDLINE citation will include the multiple languages if the publisher supplies this information to PubMed.25 For example, the citation for this article in 3 languages appears in PubMed as follows:

Transcultural adaptation and validation of the Conditions of Work Effectiveness-Questionnaire-II instrument.

Bernardino E, Dyniewicz AM, Carvalho KL, Kalinowski LC, Bonat WH.

Rev Lat Am Enfermagem. 2013 Sep-Oct;21(5):1112-8. doi:10.1590/S0104-11692013000500014. English, Portuguese, Spanish.

PMID: 24142220

Simultaneous publication may appear in more than 1 journal for general announcements or new shared policies or reporting guidelines. See, for example, the following:

Taichman DB, Sahni P, Pinborg A, et al. Data sharing statements for clinical trials: a requirement of the International Committee of Medical Journal Editors. JAMA. 2017;317(24):2491-2492. doi:10.1001/jama.2017.6514

In the above cited example, the following note is included at the end of the article:

Note: This article is being published simultaneously in Annals of Internal Medicine, BMJ (British Medical Journal), Bulletin of the World Health Organization, Deutsches Ärzteblatt (German Medical Journal), Ethiopian Journal of Health Sciences, JAMA, Journal of Korean Medical Science, New England Journal of Medicine, New Zealand Medical Journal, PLOS Medicine, The Lancet, Revista Médica de Chile (Medical Journal of Chile), and Ugeskrift for Laeger (Danish Medical Journal).

5.3.2 Editorial Policy for Preventing and Handling Allegations of Duplicate Publication.

Covert duplicate publication violates the ethics of scientific publishing and may constitute a violation of copyright law or publication licenses and agreements. Editors have a duty to inform prospective authors of their policies on duplicate publication, which should be published in their instructions for authors. Reviewers should notify editors of the existence of duplicate articles discovered during their review. Authors should provide copies of duplicate or overlapping articles and manuscripts with their submitted manuscripts. Authors should also include citations to highly similar articles and any reports from the same study under their authorship in the reference list of the submitted manuscript. When in doubt about the possibility of duplication or redundancy of information in articles based on the same study or topic, authors should inform and consult the editor.

The editors of JAMA and the JAMA Network journals have adopted the following policies to prevent the practice of duplicate publication or minimize the risk of its occurrence. At the time a manuscript is submitted, the author must inform the editor in the event that any part of the material (1) has been or is about to be published elsewhere in any form or (2) is under consideration by another journal or publisher. In the case of a highly similar article or manuscript, the author should provide the editor with a copy of the other article(s) or manuscript(s) so the editor can determine whether the contents are duplicative and whether such duplication affects the editorial priority of the submitted manuscript.

Preprints are not considered duplicate publications, but authors should inform editors of previously posted preprints (see 5.6.2, Public Access and Open Access in Scientific Publication). All authors are required to complete an authorship criteria and responsibility statement, which includes the following declaration:

Neither this manuscript nor another manuscript with substantially similar content under my authorship has been published or is being considered for publication elsewhere, except as described in an attachment, and copies of related manuscripts are provided.

In addition, many journals require authors to transfer copyright ownership or grant a publication license to the journal as a condition of publication (see 5.6.5, Copyright Assignment or License). In the case of duplicate submission, copyright or publication right is likely owned by the first journal to publish the manuscript, depending on whether copyright ownership or an exclusive publication license was transferred. Journals that require authors to grant a license to publish a manuscript, including those that rely on Creative Commons licenses, also expect authors to inform editors and prospective readers of any duplicative material (see 5.6.5, Copyright Assignment or License).

Some journals may use software to screen submitted manuscripts to help identify content that may overlap with content that has been previously published in other journals.26 This software may also be used to help identify plagiarism. Such similarity-checking software relies on screening of public and private bibliometric databases and may result in false-positive results that require editors to review for type and extent of duplication (see 5.4.2, Misappropriation: Plagiarism and Breaches of Confidentiality).

In a case of suspected duplicate submission or publication, editors should first contact the corresponding author and request a written explanation. Additional actions that may be considered are described below.

The Committee on Publication Ethics (COPE) provides flow diagrams that editors may find helpful when assessing how best to address duplicate submission or publication.27 Duplicate Submission.

If an author submits a duplicate manuscript without notifying the editor, the editor should act promptly when evidence of duplicate submission is discovered.2 If duplicate submission of a manuscript is suspected before publication, the editor should notify the corresponding author and ask for a copy of the potentially duplicative material, if not already in hand, as well as copies of any other similar articles and manuscripts, and request a written explanation. After reviewing all material, the editor will then decide whether to continue to consider or to reject the submitted manuscript. If the manuscript is rejected because of duplicate submission, this reason should be indicated clearly in the decision letter. Duplicate Publication.

If an editor suspects that duplicate publication has occurred, the editor should contact the corresponding author and all coauthors and request a written explanation. If necessary, the editor (possibly with the benefit of additional expert opinion) may consult the editor of the other journal in which the material appeared. If both editors agree that duplication has occurred, the editor of the second journal to publish the article should inform the author of the intention to publish a notice of duplicate publication in a subsequent issue of the journal. It is preferable that this notice be signed by the author or be accompanied by a letter of explanation from the author, but a notice of duplicate publication should be published without the author’s explanation or approval if none is forthcoming.2 Depending on the situation, the editor may also choose to notify the author’s institutional supervisor (eg, department chair, dean) to request an evaluation of the duplication or request assistance with acquisition of an appropriate letter from the author. Notice of Duplicate Publication.

The notice of duplicate publication should be published formally in print and/or online and listed in the table of contents or online index of the journal in a citable format to ensure that the notice will be indexed appropriately in literature databases. The notice should be labeled or titled as “Notice of Duplicate Publication” and it may be published as correspondence or as a correction or erratum. The US National Library of Medicine identifies duplicate articles in its bibliographic database by adding a publication type of “Duplicate Publication” to the record of each duplicate article and links subsequently published notices of duplicate publication to the citations of the duplicate articles.22

It is preferable to publish an explanation from the author(s) of the duplicate article with the notice, but this is not always possible or necessary. The words Duplicate Publication should be included in the title of the notice, which should include complete citations to all duplicate articles (because there may be more than 1). Examples of Notices of Duplicate Publication published as Letters from the authors or editors are as follows:

Xi B. Notice of duplicate publication: “Performance of the Simplified American Academy of Pediatrics Table to Screen Elevated Blood Pressure in Children.” (JAMA Pediatr. doi:10.1001/jamapediatrics.2018.1923). JAMA Pediatr. 2018; 172(12):1198-1199. doi:10.1001/jamapediatrics.2018.4068

Freischlag J. Notice of duplicate publication: “Pathogenesis of Barrett Esophagus: Deoxycholic Acid Up-regulates Goblet-Specific Gene MUC2 in Concert With CDX2 in Human Esophageal Cells” (Arch Surg. 2007;142 [6]:540-545). Arch Surg. 2008;143(8):807. doi:10.1001/archsurg. 143.8.807-a

Box 5.3-2 provides an example of such a notice (wording would depend on the circumstances in each case), and Box 5.3-3, an example of a table of contents listing. Note: The examples in Boxes 5.3-2 and 5.3-3 are hypothetical and are intended to show all the elements needed for a published notice of duplicate publication and to ensure appropriate identifiability and indexing of such notices.

Box 5.3-2. Hypothetical Example of a Notice of Duplicate Publication From the Journal

Correction: Notice of Duplicate Publication: “Report of Multidrug-Resistant Mycobacterium tuberculosis Among Residents of a Long-term Care Facility” (Arch Infect Dis. 2014;270[12]:2008-2012.)

The article “Report of Multidrug-Resistant Mycobacterium tuberculosis Among Residents of a Long-term Care Facility” that I published in the December 2014 issue of the Archives of Infection and Disease1 is virtually identical to an article describing the same 35 cases in similar words, that I published in the Journal of New Results, September 2014.2

I offer my sincere apologies to the readers of the Archives of Infection and Disease. I did not understand that my 2 manuscripts would be considered duplicative at the time I submitted them. I thought that since the 2 journals are read by different groups, some overlap in wording would be acceptable.

Anthony S. Smith, MD

Main University School of Medicine

Chicago, Illinois


1.Smith AS. Report of multidrug-resistant Mycobacterium tuberculosis among residents of a long-term care facility. Arch Infect Dis. 2014;270(12):2008-2012.

2.Smith AS. Multidrug-resistant tuberculosis among the elderly: an epidemiological assessment. J New Results. 2014;32(9):150-154.

Box 5.3-3. Hypothetical Example of a Duplicate Publication Notice Listing in a Journal’s Table of Contents


Smith AS. Notice of duplicate publication: “Report of Multidrug-Resistant Mycobacterium tuberculosis Among Residents of a Long-term Care Facility” (Arch Infect Dis. 2014;270[12]:2008-2012.)

All journals should develop and publish policies on duplicate submission and publication. In addition, journals should develop procedures for evaluating possible violations of such policy and actions to be taken once a violation has been determined to have occurred. Such procedures include requesting an explanation from the author(s) and, if duplicate publication is determined to have occurred, notifying the other journal(s) involved, considering notifying the author’s dean, director, or supervisor (this may be necessary if the author does not provide a satisfactory explanation), and publishing a notice of duplicate publication. As noted previously, COPE has useful flow diagrams that recommend steps to take if duplicate submission or publication is suspected.27 Some journals in specific fields have decided to notify each other about cases of proved duplicate publication and sanction or ban the offending author(s) from publishing in their journals for a specified period.28,29

Principal Author: Annette Flanagin, RN, MA


I thank the following for review and helpful comments: Howard Bauchner, MD, JAMA and JAMA Network; Carissa Gilman, American Cancer Society, Atlanta, Georgia; Timothy Gray, PhD, JAMA Network; Iris Y. Lo, JAMA Network; Ana Marušić, MD, PhD, Journal of Global Health and University of Split School of Medicine, Croatia; Fred Rivara, MD, MPH, JAMA Network Open and University of Washington, Seattle; and Elizabeth Wager, PhD, Sideview, Princess Risborough, England.


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21.Cheung VW, Lam GO, Wang YF, Chadha NK. Current incidence of duplicate publication in otolaryngology. Laryngoscope. 2014;124(3):655-658. doi:10.1002/lary.24294

22.Schein M, Paladugu R. Redundant surgical publications: tip of the iceberg? Surgery. 2001;129(6):655-661. doi:10.1067/msy.2001.114549

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24.Fontanarosa PB, Flanagin A, DeAngelis CD. Update on JAMA’s policy on release of information to the public. JAMA. 2008;300(13):1585-1587. doi:10.1001/jama.300.13.1585

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