To save readers and researchers from being overwhelmed by redundant material, we do not want to publish papers that overlap substantially with papers published elsewhere. We want to make up our own minds on the degree of overlap. Whenever a paper submitted to the journal overlaps by more than 10% with previously published work, or work submitted elsewhere, we expect authors to send us copies of those papers.

Duplicate publication is the publication of the same paper or substantially similar papers in more than one journal. Authors must explain in the submission letter any prior publication of the same or substantially similar paper, and should explain any circumstances that might lead the editor or reviewer to believe that the paper may have been published elsewhere (for example, when the title of a submitted paper is the same as or similar to the title of a previously published article).

If the editor learns that a submitted paper has been published elsewhere (in either the same or substantially similar form), the editor reserves the right to consult with other editors about the content of the papers in question. Furthermore, the editor may return the paper unreviewed, may consider no papers by any of the authors for a period of time, may announce publicly in the journal (perhaps as a simultaneous announcement with the editor of the journal that published the earlier paper) that the authors have submitted a previously published article, or may do any combination of these actions.

If the paper is accepted and published before the duplication is discovered, the editor will announce the duplication in the journal or have the authors write a letter acknowledging the duplicate publication, and the editor may notify the authors' employers.

Authors may not send the same manuscript to more that one journal at the same time. If the editor learns of possible simultaneous submission, he or she reserves the right to consult with the other editor(s) who have received the paper. Furthermore the editor may return the paper without review, or may reject it without regard to the reviews, or make this decision in discussion with the other editor(s) involved, and may decide to consider no papers from these authors for a period of time, and may also write to the authors employers, or may do any combination of these actions.

Plagiarism is the use of others' published and unpublished ideas or words (or other intellectual property) without attribution or permission, and presenting them as new and original rather than derived from an existing source. The intent and effect of plagiarism is to mislead the reader as to the contributions of the plagiariser. This applies whether the ideas or words are taken from abstracts, research grant applications, ethics committee applications, or unpublished or published manuscripts in any publication format (print or electronic).

Plagiarism is serious scientific misconduct.

Authors can submit papers published (or in press) elsewhere as supplementary material.

See Online only and supplemental material for more guidance.

1. Contact the authors to request an explanation

2. Request the raw data of the study

3. Request copies of relevant correspondence - for example, with the research ethics committee that approved the study

If an editor has concerns that a submitted paper describes something that might be considered to constitute research or professional misconduct, the case may be discussed without the author(s) permission with any or all of the following:

If the case cannot be resolved by discussion with the author(s) the editor may:

1. Ask the author(s) employer to investigate

2. Report the case to the appropriate authorities

3. Where appropriate, contact the Chair of the research ethics committee who approved the study

If, during the course of reviewing a paper, an editor is alerted to possible problems (for example, duplicate publication or fraudulent data) in another publication, the editor may contact the journal in which the other publication appeared to raise the concern.

Journal of Medical Ethics is a member of the Committee on Publication Ethics (COPE). Cases of suspected research or publication misconduct may also be referred to COPE in an anonymised format.

Where the matter affects the interests of the BMJ Publishing Group, the BMJ Ethics Committee

Any other appropriate person(s) at the editor's discretion

The editor will inform the author(s) if he or she takes any of the actions above.

Where the editor does find that there has been research or professional misconduct, he or she may publish a notice in the journal and may impose any of the sanctions suggested in the COPE guidelines. Where the editor does find that there has been serious research or professional misconduct relating to a published article he or she will retract that article.