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Bailey16 and von Elm et al17 used classification systems

to analyze the practices of duplicate publication in their

respective fields. Each method offers an interesting insight

Elm et al produced an algorithm with 6 endpoints toaddress these issues, including the Ingelfinger rule.3,4 categorize various patterns of duplicate publications: pattern

1A, identical study sample and identical outcomes; pattern

1B, identical study sample and identical outcomes but 2 or0161-4754/$32.00One of the landmark events relating to duplicate

publication is the publication of the 1969 editorial in the

New England Journal of Medicine by Franz Joseph Ingel-

finger. Now known for the Ingelfinger rule, he proposed that

manuscripts should only be considered for publication in his

journal if they were not submitted or published elsewhere.2

Since that time, many journals have adopted the same

policy. However, there are some who suggest that the

on the variations and intricacies of duplicate publication.

Bailey16 separated his classification system of similarity into

5 levels: level I, 10% or more of the contents are identical;

level II, highly similar contents without exact duplication;

level III, subsets (salami slicing) of the same study; level IV,

number of subjects in the study increases without new

conclusions or changes in the intervention; and level V, the

same message is published for different readerships. von17who will be affected by the information contained in

the literature.1readership to ens

importantly, becauCopyright D 20doi:10.1016/j.jmtudy should be presented as a whole to the appropriately combining them into 1 study), or the aut

may add new data and make a study appear new.1,6,9-11ting a study or a set of data. One can slice a cake

ares, triangles, rounds, or layers. Which of these is

way to slice a cake? Unfortunately, this is exactly

ng question. The point is that the cake that is being

to, the data set or the study, should not be sliced at

various orders.11,12 In some cases, redundancy may inc

salami slicing of the data into subsets instead of represen

the study as a whole (eg, using data collected from one g

of patients but carving out different data subsets instearepresenothers5,8,15 and may have similar or identical authors in

ludeEDITORIAL

REPETITIVE, DUPLICATE, ANDPUBLICATIONS: A REVIEW FO

Claire Johnson, MSEd, DCEditor

ABSTRACT

Repetitive, duplicate, and redundant publications are an

affects science and carries with it sanctions of consequen

classifications, impact, sanctions, and prevention strategie

(J Manipulative Physiol Ther 2006;29:505-509)

TRYING TO DEFINE THE PROBLEM

It would seem that the topic of duplicate publication is

easy to characterize. However, defining this issue is

challenging because of the many varieties in which one can

slice, reformat, or reproduce material from a study. This issue

also goes beyond the duplication of a single study because it

is possible that the same or similar data can be published in

the early, middle, and late stages of an ongoing study. This

can have a damaging impact on the scientific literature base.

Similar to slicing a cake, there are many ways of06 by National University of Health Sciences.pt.2006.07.001REDUNDANTR AUTHORS AND READERS

mportant concern in the scientific literature. Their occurrence

e. This editorial provides a brief review of the definitions,

regarding repetitive, duplicate, and redundant publications.

Redundant, duplicate, or repetitive publications occur

when there is representation of 2 or more studies, data sets, or

publications5-15 in either electronic or print media.7,15 The

publications may overlap partially or completely, such that a

similar portion, major component(s), or complete represen-

tation of a previously/simultaneously or future published

study is duplicated. These publications may share the same,

similar, or overlapping data, hypotheses, discussion, meth-

ods, results, and/or conclusions.6,8,9 Typically, one or more

of the publications do not have full cross-references tomore articles are combined to produce a different article;

pattern 2, identical study sample but different outcomes;

505

larger trial published in separate pieces; and pattern 4,

but also wastes resources and has a negative impact on the

of their previous writings on the same topic in another of

In each case, full disclosure and agreement are necessary.

The International Council of Medical Journal Editors has

published several criteria necessary if repetitive, redundant,

or duplicate publication is acceptable. These conditions

include the following: (1) editors from both journals have

given the author(s) approval; (2) priority of the primary

publication is respected; (3) the secondary publication,

which may be an abbreviated version, is intended for a

different readership; (4) the secondary publication accu-

rately represents the primary publication; (5) the secondary

publication clearly states that it is based on or replicates the

primary publication; and (6) the title of the secondary

publication indicates that it is a secondary publication.7

WHO IS RESPONSIBLE?

Embedded in the definition of authorship is the fact that

authors are ultimately the ones responsible for presenting,

publishing, and defending their work. Therefore, the

Fig 1. Problems caused by duplicate publication.

506 Journal of Manipulative and Physiological TherapeuticsJohnsonSeptember 2006Repetitive, Duplicate, and Redundant Publicationstheir publications, without specifically citing it formally in

quotes. . .this usually violates the copyright that has beenassigned to the publisher. . .Q5

WHEN IS DUPLICATE PUBLICATION ACCEPTABLE?

There are few instances when republication is acceptable;

all of these include proper disclosure to all involved (eg,literature base (Fig 1).

WHY DO PEOPLE DO IT?

There are many proposed reasons for why authors

engage in the act of covert or overt duplicate publication.

Ultimately, the quandary lies in whether an author fully

discloses to the editor that there is a potential that the

submitted article contains some or much of the data from

another study (unpublished or not). Such redundancy should

be divulged to the readership by including a disclosure in

the text of the article. Table 1 cites some reasons for

duplicate publication.

It is important to note that although authors have

published a body of text, they are not allowed to republish

either portions or the whole of their work. As stated in the

World Association of Medical Editors guidelines, b[s]elf-plagiarism refers to the practice of an author using portionsduplication with different study samples and different

outcomes. Upon review of these classification systems, it

is evident that duplicate publication is a complex issue.

WHAT IS WRONG WITH DUPLICATE PUBLICATION?

Duplicate/redundant publication is especially improper

when it is deceptive. Covert submission and publication of

previously published material are deceiving to those who

read or use the information contained in the article.

Most would agree that if the editors, peer reviewers,

readers, and all end users of the information were informed

about an overlap or duplication of publication, appropriate

decisions could be made. However, when authors do not

disclose that the same study sample is being used or that an

earlier study is being supplemented to produce a larger

sample size although the earlier study included the same

patients, they would be misleading the readership, and some

would consider such act as a form of ethical misconduct.

Redundant publication not only has ethical and legal issuespattern 3A, different study samples with new data added to a

preliminary article with similar outcomes; pattern 3B,

different study samples with similar outcomes, part of aeditor, readers).1 Fig 2 lists some instances when this may

be appropriate.ultimate burden of integrity falls upon the authors. Although

some authors may claim ignorance to publication guidelines,

rra

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JohnsonJournal of Manipulative and Physiological Therapeutics

Repetitive, Duplicate, and Redundant PublicationsVolume 29, Number 7507Table 1. Several reasons prompting duplicate publication

Considered as noble reasons

Considered as questionable o

inappropriate reasons

To reach a larger audience9,11

To report study findings to

the media15

To inflate publication bibliog

on grant applications6,11

To increase publication recor

on curriculum vitae6,9

To secure a patent or financi

To influence promotion of ramany journals clearly publish what is or is not acceptable

with regard to duplicate publication. Thus, authors must read

the journal instructions and must be aware of these

issues.16,18 As Tobin10 stated, b [t]he editor is not the police,it is ultimately the authors who are responsible.Q

Editors have a different but equally tasking responsibility

in relation to duplicate publication. Editors must clearly

define and implement the ethical standards of their

journals.21 Although editors are responsible for follow-

ing up on ethical misconduct issues when they come

to light, they are not solely responsible for investigating

and/or punishing the authors. The structure of the greater

scientific community, including authors institutions, ethics

boards, licensing boards, and funding agencies, should also

be involved.21

Although challenging to define, it is even more difficult

to identify duplicate publication.19 Thus, the responsibility

to recognize and report duplication rests with all who

Some or all of the following have been recommended

Fig 2. Situations when duplicate publication may be acceptable.and should be based on the circumstances of the situation. If

duplication is identified before or after acceptance but

before publication, the manuscript should be rejected

outright.7,9 If duplicate publication is identified after

publication, the editor should communicate in one or more

of the following ways: (1) send a letter of reprimand to the

authors5,20; (2) notify editors of other journals20; (3) informcome in contact with the study, including colleagues aware

of ones work, peer reviewers, editors, and the readership

of the journal. At times, clandestine duplicate publications

are divulged when someone reads a journal article and

informs the editor of the journal or an official of the

authors institution.

ACTIONS AND SANCTIONS ONCE COVERTDUPLICATION IS IDENTIFIED

Once inappropriate duplicate publication has been recog-

nized, investigated, and confirmed, there are many suggested

actions. These actions are intended to correct the record,

notify others that misconduct has taken place, and provide

incentive to authors not to replicate this unethical behavior.

Considered as reasons caused by ignorance

phy

listed

interest6

6,10

Some authors are not aware that

duplicate/redundant publications are

inappropriate or exemplify ethical misconduct1,19

During the request for revision, some editors

recommend removing content or publishing

an article as 2 studies; thus, although editors

may not be suggesting to republish the data,

authors may misunderstand and think that

this is being condoned and hence publish out

of ignorance1the authors clinical institution5,11,20,21,22; (4) inform the

authors academic institution5,11,20,21,22; (5) inform ethics/

institutional review boards21,22; (6) inform professional

organizations18; (7) inform funding/granting agencies (eg,

National Institutes of Health)5,20; (8) inform indexing

services (eg, PubMed)20,21; and (9) inform a professional

ethics body (eg, Office of Research Integrity).22

Once the appropriate bodies have been informed, the

next step is to make a correction to the record, which may be

accomplished in several ways. A notice of duplicate/

redundant publication or plagiarism may be published in

the journal.5,10,20,21,22 A notice of retraction may also be

published.5,7,22 Some writers suggested that the journal

publish a letter of apology from the authors.18 Others

recommended that the journal publish reprimanding edito-

rials.11 Finally, articles may be retracted from journals5,7,9,22

and/or from indexing services.5,7,11,22

Editors should ensure that their journals policy on

1. Huth EJ. Repetitive and divided publication. In: Jones AH,

508 Journal of Manipulative and Physiological TherapeuticsJohnsonSeptember 2006Repetitive, Duplicate, and Redundant Publicationsduplicate publication is clearly stated and easy to fol-

low.1,5,11,20,21 Editors should publish editorials or commen-

taries to educate readers about this topic.1 Journals should

have in place definitions, procedures for handling suspected

manuscripts, reporting policies, corrections/retractions, and

sanctions.16,22 Editors may screen each manuscript for

redundancy if there are enough resources in their journal

office to complete this task successfully. An alternate

approach may be to randomly screen submissions for signs

of duplication.1,11,20 However, screening will not accountThere are recommended sanctions for authors who have

submitted covert duplicate or redundant publications.

Several writers suggested restricting authors from future

submissions to journals in which the misconduct was

recognized.10,11,20 A more punitive sanction recommended

is to restrict authors from future publication in journals

belonging to an editorial group, thereby greatly reducing the

number of journals to which a sanctioned author may submit

a manuscript.11

HOW TO PREVENT DUPLICATION

Prevention is possibly the best approach to duplicate

publication. Both the editor and the author can take steps

toward preventing this from becoming an issue. First, the

author should read in detail the instructions for authors of

the journal to which the manuscript is being submitted. This

document will usually provide detailed information regard-

ing the journals policy toward redundant publication. If

uncertain, the author should contact the editor and ask for

any necessary clarification. The author should fully disclose

to the editor in the cover letter and in the manuscript that

some or all of the same study contents or data have been

used/will be used in published articles, currently submitted

articles, unpublished papers, or any other article relating to

the data or content of the article.5,7,12,18 The author should

include in the cover letter or sign a statement denying or

disclosing overlap with any other work.7,20 It is suggested

that copies of the other work be submitted to the journal at

the same time as the study for consideration.7,21 As a rule of

thumb, Tobin10 stated, b[n]o matter how small the overlap,authors need to inform us [editors] about related work.Q

Authors should be cautious to report information about

their study to the media, funding agencies, government

agencies, or others who disseminate information before the

publication of their study.7 Some reporting in advance of

publication may be warranted but should be discussed with

the editor and agreed upon in advance.

Peer reviewers should notify the editor if duplicate

publication is supposed during the review process.1,20 After

publication, readers are encouraged to notify the editor if

there is suspicion of duplicate publication.for manuscripts that are currently in press, have been

indexed in an obscure database, or have simultaneouslyMcLellan F, editors. Ethical issues in biomedical pub-licationBaltimore7 Johns Hopkins University Press; 2000.p. 112-36.

2. Toy J. The Ingelfinger rule: Franz Ingelfinger at the NewEngland Journal of Medicine, 1967-77. Science Editor 2002;25:195-8.

3. Germenis AE. Beyond the Ingelfinger rule: the intellectualproperty ethics after the end of biomedical journals monopoly.been submitted to another journal. Some encourage editors

to use deterrents, such as reporting suspected manuscripts,

publishing reprimanding articles, and contacting the of-

fending authors institutions.11,22 However, I feel strongly

that prevention is the best approach, hence the publication

of this editorial.

THE JMPT POLICY AND CONCLUSION

It is my hope that through this editorial, the readership

of the JMPT will have a better understanding of this

complex issue. The JMPTs policy regarding repetitive,

duplicate, or redundant publications is presented below.

Additional information is included in the JMPT instruc-

tions for authors, available on the journals website at

www.mosby.com/jmpt.

The JMPT does not publish articles containing

material that has been reported at length elsewhere.

The corresponding author must include in the cover

letter a statement to the editor about all submissions

and previous materials that might be considered to be

redundant or duplicate publication of similar work,

including if the manuscript includes materials on

which the authors have published a previous report or

have submitted a related report to another publication.

Copies of the related material may be requested by the

editor in order to assist with the editorial decision of

the paper.

If redundant or duplicate publication is attempted

or occurs without proper disclosure to the editor,

editorial action will be taken as follows. If it is

confirmed that a paper is a duplicate or redundant

publication and is discovered in the prepublication

phase, the paper will be rejected, even if an accept

notice has been distributed previously to the authors.

If duplicate or redundant publication is confirmed

after publication, the paper will be retracted and the

appropriate boards/institutions notified.

REFERENCESMed Inform Internet Med 1999;24:165-70.4. Jacobson MW. Biomedical publishing and the internet: evo-

lution or revolution? J Am Med Inform Assoc 2000;7:230-3.

5. World Association of Medical Editors (WAME). WAMErecommendations on publication ethics policies for medicaljournals: originality, prior publication, and media relations.[monograph on the Internet]. London7 WAME; 2005 [[cited2006 Jul 4]. Available from: http://www.wame.org/pubethicre-com.htm#orig].

6. Elstein AS, Cadmus C, Pitkin R, Mundy D, McDowell C.Salami science: are we still allowing it? Science Editor 1998;21:200.

7. International Council of Medical Journal Editors (ICMJE).Uniform requirements for manuscripts submitted to biomedicaljournals: writing and editing for biomedical publication. IIIDoverlapping publications [monograph on the internet]. Phila-delphia7 ICMJE; 2006 [[cited 2006 Jul 4]. Available from:http://www.icmje.org/#over].

8. Committee on Publication Ethics (COPE). Guidelines on goodpublication practice [monograph on the Internet]. London7COPE; 2003 [[cited 2006 Jul 4]. Available from: http://www.publicationethics.org.uk/guidelines].

9. Benos DJ, Fabres J, Farmer J, et al. Ethics and scientificpublication. Adv Physiol Educ 2005;29:59-74.

10. Tobin MJ. AJRCCMs policy on duplicate publication:infrequently asked questions. Am J Respir Crit Care Med2002;166:433-4.

11. Schein M, Paladugu R. Redundant surgical publications: tip ofthe iceberg? Surgery 2001;129:655-61.

12. Rivara FP, Christakis DA, Cummings P. Duplicate publication.Arch Pediatr Adolesc Med 2004;158:926.

13. Kassirer JP, Angell M. Redundant publication: a reminder.N Engl J Med 1995;333:449-50.

14. Rogers LF. Salami slicing, shotgunning, and the ethics ofauthorship. AJR Am J Roentgenol 1999;173:265.

15. Iverson C, Flanagin A, Fontanarosa PB, et al. AmericanMedical Association manual of style: a guide for authors andeditors. 9th ed. Philadelphia7 Lippincott Williams & Wilkins;1998. p. 98-100.

16. Bailey BJ. Duplicate publication in the field of otolaryngol-ogyhead and neck surgery. Otolaryngol Head Neck Surg2002;126:211-6.

17. von Elm E, Poglia G, Walder B, Tramer MR. Different patternsof duplicate publication: an analysis of articles used insystematic reviews. JAMA 2004;291:974-80.

18. Reeves DS, Wise R, Drummond CW. Duplicate publication: acautionary tale. J Antimicrob Chemother 2004;53:411-2.

19. Tramer MR, Reynolds DJ, Moore RA, McQuay HJ. Impact ofcovert duplicate publication on meta-analysis: a case study.BMJ 1997;315:635-40.

20. Yank V, Barnes D. Consensus and contention regardingredundant publications in clinical research: cross-sectionalsurvey of editors and authors. J Med Ethics 2003;29:109-14.

21. Council of Science Editors. Editorial policy statements.[monograph on the internet]. Reston (Va)7 Council of ScienceEditors; 2006 [[cited 2006 Jul 4]. Available from: http://www.councilscienceeditors.org/services/cse_editorial_policies.cfm].

22. Office of Research Integrity. Managing allegations of scien-tific misconduct: a guidance document for editors. Rockville(Md)7 Office of Research Integrity, Office of Public Healthand Science, US Department of Health and Human Services;2006 [Available from: http://ori.dhhs.gov/documents/masm_2000.pdf].

JohnsonJournal of Manipulative and Physiological Therapeutics

Repetitive, Duplicate, and Redundant PublicationsVolume 29, Number 7509

Repetitive, Duplicate, and Redundant Publications: A Review for Authors and ReadersTrying to Define the ProblemWhat Is Wrong With Duplicate Publication?Why Do People Do It?When Is Duplicate Publication Acceptable?Who Is Responsible?Actions and Sanctions Once Covert Duplication Is IdentifiedHow to Prevent DuplicationThe JMPT Policy and ConclusionReferences