# Avoiding Duplicate Publication of Your Systematic Review ## Quick Answer - Submit your systematic review to only one journal at a time and disclose any preprint or prior version to the editor during submission. - Check the target journal's preprint policy before posting or depositing any version of your manuscript. - Cite and link any prior version of your work clearly in the submitted manuscript so editors and reviewers can assess overlap. ## Understanding Duplicate Publication in Systematic Reviews Duplicate publication occurs when a work substantially overlaps with another already published work without proper cross-referencing or disclosure. For systematic reviews, this risk is especially high because the methodology is standardized and the same body of evidence can be analyzed multiple times with minor changes. The [Committee on Publication Ethics Core Practices](https://publicationethics.org/core-practices) identifies redundant publication as a form of research misconduct that journals treat seriously. Editors screen submissions for overlap, and when they detect duplicate or redundant content, they may reject the manuscript, retract a published article, or notify the author's institution. The practical problem for authors is not usually an intention to deceive. It is uncertainty about what counts as duplicate publication when a review has appeared as a preprint, a conference abstract, a thesis chapter, or a registered protocol. Each of these prior forms can create overlap with the final journal article, and the rules differ by journal and by publisher. Systematic reviews present a particular challenge because their value depends on transparency and reproducibility. A reader who encounters two versions of the same review without clear links cannot tell which is current, which is complete, and which should inform clinical or policy decisions. This confusion undermines the purpose of the review and can distort the evidence base. ## What Counts as Duplicate Publication Duplicate publication is not limited to publishing the same PDF in two journals. It includes substantial overlap in the research question, the search strategy, the data extracted, and the conclusions drawn. The [EQUATOR Network](https://www.equator-network.org/) emphasizes transparent reporting as the mechanism for readers to understand exactly what a study did and found. When two papers report the same systematic review with different titles or minor wording changes, readers cannot easily detect the overlap without the authors disclosing it. Common forms of problematic overlap include: - Publishing the same systematic review in two journals without cross-referencing - Splitting one systematic review into multiple papers that each report a subset of the same searches and data without clear linkage - Republishing a review with updated search dates but presenting it as a new review without citing the original - Submitting a manuscript that is substantially identical to a preprint without informing the journal The [National Library of Medicine Research Methods Resources](https://www.ncbi.nlm.nih.gov/books) gateway provides access to methodological references that define what constitutes a systematic review and how reporting standards apply. These resources make clear that the defining feature of a systematic review is its explicit methodology, which means two reviews of the same question using the same methods are likely to overlap substantially. ## Preprint Policies and Prior Versions Preprints are publicly available versions of a manuscript posted before peer review. They are common in biomedical and life science fields because they speed dissemination. However, posting a preprint creates a prior public version of your work, and journals handle this differently. Before you post a preprint, check the target journal's policy. Some journals accept manuscripts that have appeared as preprints and require you to disclose this during submission. Others do not consider preprints to be prior publication and welcome the manuscript. A few journals will not consider manuscripts that have been posted as preprints at all. The [ORCID for Researchers](https://info.orcid.org/researchers) resource explains how researchers can maintain a complete record of their work, including preprints and other outputs. Keeping your ORCID record current helps editors and readers see the full landscape of your outputs, which supports transparency even when policies vary. When you submit a manuscript that has a preprint version, you should: - Disclose the preprint in your cover letter to the editor - Cite the preprint in the manuscript where relevant - Update the preprint with a link to the published version once accepted - Ensure the preprint and the published version are clearly cross-referenced ## Simultaneous Submission Rules Simultaneous submission means sending the same manuscript to more than one journal at the same time. This practice is prohibited by virtually all journals because it wastes editor and reviewer time and creates the risk of duplicate publication if two journals accept the work. The [Committee on Publication Ethics Core Practices](https://publicationethics.org/core-practices) states that journals should have clear policies on submission and that authors should follow them. The standard expectation is that a manuscript is under consideration at only one journal at a time. If you withdraw a manuscript from one journal, you may submit it to another, but you should not have it under active review at multiple journals. For systematic reviews, the same rule applies to the full manuscript. You may have a registered protocol in a registry such as PROSPERO, and you may have posted a preprint, but the manuscript itself should be with one journal at a time. ## Proper Citation of Prior Versions When your systematic review has prior versions, proper citation is the mechanism that prevents an accusation of duplicate publication. The goal is to make the relationship between versions explicit so that no reader or editor can mistake one for an unauthorized duplicate. The [EQUATOR Network](https://www.equator-network.org/) provides reporting guidelines that help authors describe their methods completely. When you cite a prior version, you should: - Cite the preprint or protocol in the methods section where relevant - Explain in the cover letter how the submitted manuscript differs from any prior version - Reference the prior version in the text when you discuss the development of the review - Link the published article to the preprint and the protocol The [National Institutes of Health Grants and Funding](https://grants.nih.gov/) pages describe how NIH expects grantees to manage their research outputs. While these pages focus on grant administration, they reinforce the principle that research outputs should be traceable and that duplication undermines the integrity of the scientific record. ## At a Glance | Scenario | What You Should Do | What to Avoid | | --- | --- | --- | | You posted a preprint before journal submission | Disclose the preprint in your cover letter and cite it in the manuscript | Submitting without mentioning the preprint to the editor | | You submitted to one journal and want to try another | Withdraw the manuscript from the first journal before submitting elsewhere | Keeping the manuscript under review at two journals at once | | Your systematic review updates a previously published review | Cite the original review and explain what the update adds | Presenting the update as a brand new review without reference to the prior work | | Your thesis chapter overlaps with your journal manuscript | Disclose the overlap to the editor and cite the thesis if it is publicly available | Submitting the thesis chapter unchanged without disclosure | ## Practical Workflow for Avoiding Duplicate Publication ### Step 1: Map All Prior Versions of Your Work Before you prepare a journal submission, list every version of your systematic review that exists or will exist. This includes preprints, conference abstracts, posters, thesis chapters, registered protocols, and reports to funders. For each version, note the date it became public, the platform where it appears, and its digital object identifier if one exists. The [ORCID for Researchers](https://info.orcid.org/researchers) resource describes how to maintain a complete record of your research outputs. Adding all versions of your review to your ORCID record gives you a single place to track what is public and when it appeared. ### Step 2: Check the Target Journal Policy Read the target journal's instructions to authors before you submit. Look specifically for statements about prior publication, preprints, and overlapping work. If the policy is unclear, email the editorial office and ask. Keep the response for your records. The [Committee on Publication Ethics Core Practices](https://publicationethics.org/core-practices) describes the responsibilities of journals to have clear policies. If a journal does not state its policy, that is a reason to ask directly instead of assume. ### Step 3: Draft Your Disclosure Language Write a paragraph for your cover letter that lists all prior versions and explains how the submitted manuscript differs from each. Be specific. State the search date range, the number of studies included, and any analyses that are new in this version. The [EQUATOR Network](https://www.equator-network.org/) reporting guidelines can help you describe your methods precisely so that the differences between versions are clear. ### Step 4: Cite Prior Versions in the Manuscript In the methods section, cite your protocol and any prior version that informed the current work. In the discussion, note how this review relates to any prior publication of the same or similar question. This is not a sign of weakness. It is a sign of transparent scholarship. ### Step 5: Track Submission Status Keep a record of where your manuscript is under review. If you decide to withdraw it, send a formal withdrawal notice to the editor and wait for confirmation before submitting elsewhere. ## Records and Measurements Maintain a submission log for each systematic review. The log should include: - The date you posted any preprint - The date you submitted to each journal - The date you withdrew from any journal - The journal policy on prior publication - The disclosure language you sent to each editor - The final publication details This log serves as your evidence of good faith if a question about duplicate publication ever arises. The [National Institutes of Health Grants and Funding](https://grants.nih.gov/) pages describe record-keeping expectations for NIH-funded work, and the same principle of maintaining clear records applies to all research outputs. ## Common Failure Patterns ### Failure to Disclose a Preprint Authors sometimes assume that because a preprint is not peer reviewed, it does not count as prior publication. This assumption is risky. Many journals require disclosure of preprints, and editors may consider a failure to disclose as an ethical violation even if the preprint was posted openly. ### Submitting to Multiple Journals to Speed Acceptance Authors under time pressure may submit to several journals at once, planning to withdraw from all but one if multiple accept. This practice is prohibited and can result in rejection from all journals involved if detected. ### Updating a Review Without Citing the Original An updated systematic review that does not cite the original version can appear to be duplicate publication. The update should clearly state that it is an update, cite the original, and explain what new evidence was added. ### Publishing Thesis Chapters Without Disclosure If your thesis is publicly available and contains a chapter that is substantially the same as your journal manuscript, you must disclose this to the editor. Some journals consider thesis publication to be prior publication, while others do not. The editor needs the information to make that decision. ## Welfare and Safety Context Duplicate publication is not a safety issue in the same way as a faulty drug dose or a failed piece of equipment, but it has consequences for the integrity of the evidence base. Systematic reviews are used to inform clinical guidelines, funding decisions, and public policy. When the same review appears multiple times without clear cross-referencing, decision makers may count the same evidence more than once, which can distort the conclusions of subsequent analyses. The [National Institutes of Health Data Management and Sharing Policy](https://sharing.nih.gov/data-management-and-sharing-policy) describes expectations for managing and sharing research outputs. The principle behind these expectations is that research should be transparent and reproducible. Duplicate publication undermines that principle because it makes it harder to trace which version of a review is authoritative. ## Limitations and Professional Escalation The guidance in this article reflects general publication ethics principles, but journal policies vary. A policy that one journal accepts may be rejected by another. You must check the specific policy of each journal you target. If you are uncertain whether a prior version of your work creates a duplicate publication risk, escalate the question to a professional. Options include: - The editorial office of the journal you plan to submit to - A research integrity officer at your institution - A senior colleague with editorial experience - The [Committee on Publication Ethics](https://publicationethics.org/core-practices) resources for guidance on ethical dilemmas If you discover after publication that your article overlaps with a prior version in a way you did not disclose, contact the journal editor immediately. Explain the situation and propose a correction. Prompt action is the best way to limit the consequences. ## Building a Decision Framework for Prior Version Overlap A practical decision framework helps you determine whether a specific prior version of your systematic review creates an unacceptable duplicate publication risk before you submit. The framework below uses three assessment dimensions that map directly to the questions editors ask when they screen submissions. Work through each dimension for every prior version you have identified in your submission log. ### Dimension 1: Substantive Overlap The first question is how much of the prior version's content appears in your submitted manuscript. Substantive overlap is not measured by word count alone. It is measured by the elements that define a systematic review: the research question, the search strategy, the inclusion and exclusion criteria, the data extracted from included studies, and the conclusions drawn. For each prior version, compare these elements against your manuscript. The [EQUATOR Network](https://www.equator-network.org/) reporting guidelines provide a structured way to describe your methods, which makes this comparison easier because you can map each methodological element side by side. If the research question is the same, the search strategy is the same, and the included studies are the same, the overlap is substantive even if you have rewritten every sentence. A conference abstract that reports preliminary results from a subset of your included studies is not necessarily substantive overlap if your manuscript reports the full review. A preprint that reports the complete review with the same search dates and the same included studies is substantive overlap. A thesis chapter that contains the full methods and results sections of your review is substantive overlap if the thesis is publicly available. ### Decision 2: Public Availability The second dimension is whether the prior version is publicly available and how easily a reader can find it. A version that exists only in your private files creates no duplicate publication risk because no reader can encounter it. A version that is publicly available creates a risk because a reader can find both versions and wonder which one is authoritative. Public availability exists on a spectrum. A preprint on a repository such as bioRxiv or medRxiv is clearly public. A conference abstract published in a proceedings volume is public. A thesis deposited in a university repository is public. A thesis that sits only in a university library and is not indexed online may be less visible, but it is still discoverable by a determined reader. The [ORCID for Researchers](https://info.orcid.org/researchers) resource explains how researchers can maintain a complete record of their outputs, which means that even versions you do not consider public may be linked to your researcher profile and therefore discoverable. The key question is not whether you think a reader will find the prior version. The key question is whether a reader could find it. If the answer is yes, you must disclose it. ### Decision 3: Journal Policy and Editorial Expectation The third dimension is the specific policy of the journal you plan to submit to. This dimension is the one that varies most across journals and publishers. Some journals explicitly state that preprints do not count as prior publication. Others state that any publicly available version, including a preprint, makes the work ineligible for consideration. Still others leave the question open and expect you to disclose all prior versions so the editor can decide. The [Committee on Publication Ethics Core Practices](https://publicationethics.org/core-practices) describes the responsibility of journals to have clear policies on these matters. In practice, however, policies vary widely, and some journals do not state their position clearly. When the policy is unclear, you should ask the editorial office directly and record the response in your submission log. ### Applying the Framework To apply the framework, create a table for each prior version of your review. List the version, the date it became public, the platform where it appears, and then answer the three questions: - Does the prior version contain the same research question, search strategy, and included studies as your manuscript? - Is the prior version publicly available or discoverable through your researcher profile? - Does the target journal policy address this type of prior version, and if not, what did the editor say when you asked? If the answer to the first question is yes and the answer to the second question is yes, you have a potential duplicate publication risk regardless of the journal policy. You must disclose the prior version and explain the differences in your cover letter. If the answer to the first question is no, the prior version is likely not a duplicate publication risk, but you should still disclose it if it is publicly available and related to your review. The [National Library of Medicine Research Methods Resources](https://www.ncbi.nlm.nih.gov/books) gateway provides access to methodological references that define what constitutes a systematic review. These references help you make the substantive overlap comparison because they specify the elements that define a systematic review. If your prior version contains all of those elements, the overlap is substantive. ### Applying the Framework to Common Scenarios Consider a protocol registered in PROSPERO. The protocol contains your research question, your search strategy, and your planned inclusion criteria. It does not contain your results or your conclusions. The substantive overlap is partial. The protocol is publicly available. The journal policy on protocols is usually clear, and most journals welcome submissions that cite a registered protocol. The framework tells you to cite the protocol in your methods section and mention it in your cover letter, but the risk of duplicate publication is low because the protocol does not contain the results. Consider a preprint that contains the full review. The substantive overlap is high. The preprint is publicly available. The journal policy varies. The framework tells you that this is a high-risk situation. You must disclose the preprint, cite it in the manuscript, and explain what has changed between the preprint and the submitted version. If the changes are minimal, you should expect the editor to ask why you are submitting the same work again. Consider a conference abstract that reports a subset of your findings. The substantive overlap is partial. The abstract is publicly available in a conference proceedings. The journal policy may not address conference abstracts at all. The framework tells you to disclose the abstract in your cover letter and cite it where relevant. Most journals accept this situation, but the editor needs to know about the abstract to make an informed decision. ### When the Framework Indicates a Problem If the framework indicates a serious risk, you have three options. The first option is to proceed with submission and disclose the prior version fully. This is the correct option when the journal policy accepts prior versions and you can explain the differences clearly. The second option is to revise your manuscript so that the substantive overlap is reduced. This is rarely possible for a systematic review because the research question and the included studies define the work. The third option is to choose a different journal that has a policy more favorable to your situation. The [National Institutes of Health Grants and Funding](https://grants.nih.gov/) pages describe how NIH expects grantees to manage their research outputs, and the same principle of traceability applies here. Your decision framework should produce a clear record of why you made the submission decisions you made. That record is your evidence of good faith if a question about duplicate publication ever arises. ### Recording Your Decision For each prior version, record the framework outcome in your submission log. Include the date you applied the framework, the answers to the three questions, and the decision you made. This record serves two purposes. It helps you stay consistent across multiple submissions, and it provides evidence that you considered the overlap before submitting. The [Committee on Publication Ethics Core Practices](https://publicationethics.org/core-practices) describes the importance of transparency in the publication process, and a written decision record is a practical way to demonstrate that transparency. ## Frequently Asked Questions ### What is the difference between a preprint and a duplicate publication? A preprint is a version of your manuscript posted publicly before peer review. It becomes a duplicate publication risk only if you publish the same content in a journal without disclosing the preprint or if the journal considers preprints to be prior publication. The key is disclosure and cross-referencing. ### Can I submit my systematic review to a journal if I already posted it as a preprint? Yes, in most cases you can, but you must check the journal policy first. Many journals accept preprint manuscripts and require disclosure in the cover letter. Some journals do not accept work that has appeared as a preprint. Always verify before submitting. ### Is it acceptable to submit the same systematic review to two journals at the same time? No. Simultaneous submission is prohibited by virtually all journals. You must wait for a rejection or formally withdraw your manuscript before submitting it to another journal. ### How do I cite my own preprint in my journal manuscript? Cite the preprint in the methods section where you describe the development of your review. Include the preprint title, the repository name, and the digital object identifier if one exists. Also mention the preprint in your cover letter to the editor. ### What should I do if my thesis chapter is the same as my journal manuscript? Disclose the thesis to the editor during submission. Explain that the thesis is publicly available and describe how the journal manuscript differs from the thesis chapter. The editor will decide whether the overlap is acceptable. ### Can I publish an updated systematic review if I already published the original? Yes, but you must cite the original review and clearly state that the new work is an update. Explain what new searches you ran, what new studies you included, and how the conclusions changed. This transparency prevents the update from appearing to be a duplicate. ### What happens if a journal detects duplicate publication after my article is published? The journal may retract the article, issue a correction, or notify your institution. The [Committee on Publication Ethics Core Practices](https://publicationethics.org/core-practices) describes the range of actions journals can take. The best response is to contact the editor immediately and explain the situation. ### Where can I find reporting guidelines for my systematic review? The [EQUATOR Network](https://www.equator-network.org/) provides a searchable database of reporting guidelines. For systematic reviews, the relevant guideline is PRISMA, which you can access through the EQUATOR site. ## Using the Evidence | Source | Best use in this topic | Important limitation | |---|---|---| | [Research Methods Resources](https://www.ncbi.nlm.nih.gov/books) | official guidance | Check the linked page for current local requirements | | [EQUATOR Network](https://www.equator-network.org/) | official guidance | Check the linked page for current local requirements | | [Core Practices](https://publicationethics.org/core-practices) | official guidance | Check the linked page for current local requirements | ## Related Articles - [Meta-Analysis vs Systematic Review: What's the Difference?](/blog/guides/meta-analysis-vs-systematic-review-what-s-the-difference) - [Ethical Considerations in Research: A Practical Checklist for Study Design](/blog/guides/ethical-considerations-in-research-a-practical-checklist-for-study-design) - [Ethical Concerns in Research: Common Pitfalls and How to Avoid Them](/blog/guides/ethical-concerns-in-research-common-pitfalls-and-how-to-avoid-them) - [Meta-Analysis vs Systematic Review: Choosing the Right Synthesis Method](/blog/guides/meta-analysis-vs-systematic-review-choosing-the-right-synthesis-method) - [Meta-Analysis vs Scoping Review: Which Approach Answers Your Question?](/blog/guides/meta-analysis-vs-scoping-review-which-approach-answers-your-question) ## References and Further Reading - [Research Methods Resources](https://www.ncbi.nlm.nih.gov/books). National Library of Medicine. - [EQUATOR Network](https://www.equator-network.org/). EQUATOR Network. - [Core Practices](https://publicationethics.org/core-practices). Committee on Publication Ethics. - [NIH Grants and Funding](https://grants.nih.gov/). National Institutes of Health. - [ORCID for Researchers](https://info.orcid.org/researchers). ORCID. - [Data Management and Sharing Policy](https://sharing.nih.gov/data-management-and-sharing-policy). National Institutes of Health. - [NCBI Literature Resources](https://www.ncbi.nlm.nih.gov/). National Center for Biotechnology Information. - [PubMed](https://pubmed.ncbi.nlm.nih.gov/). National Library of Medicine. > This article is educational and does not replace institutional policy, professional advice, or applicable safety and regulatory requirements.