What Is Duplicate Publication?

Duplicate (redundant) publication means publishing the same data or substantially the same paper in more than one place without clear disclosure and permission. It misleads readers, can distort evidence if results are counted twice and wastes editorial resources.

What it is and is not

• Duplicate publication: the same results or text appear in two papers without cross-reference and editor approval.
• Acceptable overlap: presenting data as a conference abstract or poster before full publication is not generally regarded as prior publication by many journals, but check each journal's policy; a preprint may also be acceptable under many policies.
• Secondary publication: publishing the same paper in another language or for a different audience may be acceptable, with permission from both editors, a clear statement of the earlier publication and a different readership.
• Publishing different analyses of the same trial is acceptable if the relationship is clearly disclosed and analyses are not misrepresented as independent.

How to avoid it

1. Never submit the same manuscript to more than one journal at the same time.
2. Tell the editor about related papers, abstracts and preprints, and cite them.
3. For secondary publication, follow the ICMJE conditions and obtain permissions.
4. Report linked papers (for example a trial and its follow-up) with clear references.

Consequences

Editors may reject, retract or correct duplicated papers and may notify institutions. Duplicate publication of data may bias systematic reviews, which is a concern for research integrity.

Illustrative example

Invented for teaching. An author prepares a short conference abstract and later a full paper. She cites the abstract in the cover letter and the paper, noting that the data are the same but the paper includes full methods and follow-up. The editor accepts this.

Common pitfalls

• Submitting the same manuscript to several journals at once.
• Failing to disclose a related paper.

Key takeaways

• Disclose and cite related publications.
• One study, one primary report, with transparent links.

This page is general educational information about research methods. It is not medical, legal or regulatory advice; follow your institution's ethics board and your target journal's instructions.