Cochrane Database of Systematic Reviews: editorial policies

Author responsibilities | Authorship | Artificial intelligence | Conflicts of interest | Reporting and conduct standards | Plagiarism | Peer review | Rejection and appeals | Data sharing | Co-publication | Copyright and licence for publication | Updating Cochrane Reviews | Comments and complaints | Managing potentially problematic studies | Allegations of misconduct | Withdrawal of published articles | Publishing model and open access

Cochrane’s work is internationally recognized as the benchmark for high-quality information about the effectiveness of health care. We strive to maintain our reputation for independence and credibility through core values of transparency and research integrity, which includes adhering to key editorial and publishing policies.

The Cochrane Database of Systematic Reviews (CDSR) is a member of the Committee on Publication Ethics (COPE) and follows COPE Core Practices. Cochrane editorial staff, Cochrane Review Groups (CRGs), authors, and peer reviewers are expected to understand and follow best practice in publication ethics.

Unless otherwise stated, the policies included here apply to articles published in the CDSR. That includes Cochrane Reviews, protocols for Cochrane Reviews, Editorials, and Supplements. For information on the processes and policies for Cochrane Clinical Answers see About Cochrane Clinical Answers.

Author responsibilities

Authors are responsible for ensuring that they adhere to Cochrane’s authorship and conflict of interest policies. These policies apply to protocols, new Cochrane Reviews, updated reviews, and editorials. Authors must consider these policies when forming the author team and make modifications as appropriate as the work progresses. Authors are also responsible for adhering to Cochrane’s plagiarism policy and reporting and conduct standards.

The contact author ordinarily takes primary responsibility for communication with Cochrane’s editorial team during the submission, peer review, and publication processes. They ensure that all administrative requirements are completed, such as providing up-to-date contact details, author affiliations, and details of author contributions, and gathering conflict of interest forms and licence for publication forms. The contact author may delegate these duties to one or more co-authors if necessary.

Authorship

Criteria for authorship

Authorship is based on the following four criteria, as described by the International Committee of Medical Journal Editors (ICMJE) in the Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals. All authors are required to sign a licence for publication form that affirms all the following:

• I have made substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work.
• I have drafted the work or reviewed it critically for important intellectual content.
• I approve the final version to be published.
• I agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

The specific contributions of each author of a Cochrane Review or protocol must be individually listed under the section Contributions of authors; authors may consult CRediT (Contributor Roles Taxonomy) for standardized options. The list of authors can be the name of an individual, several individuals, a collaborative group, or a combination of one or more authors and collaborative group(s). It is the collective responsibility of the authors to determine who meets authorship criteria and the order of authors in the byline. For more details, refer to the ICMJE recommendations.

Everyone listed as an author should meet the criteria for authorship, and anyone who meets the criteria for authorship should be listed as an author.

In line with the position of COPE and other scientific publications, tools that use artificial intelligence (AI), machine learning, language models, or similar technologies to generate written content are unable to fulfil Cochrane's criteria for authorship, and therefore cannot be listed as authors on Cochrane Library publications. See Cochrane's editorial policy on AI-generated content.

Acknowledgements

Individuals who do not meet the criteria for authorship but who have helped in other ways should be offered acknowledgement in the Acknowledgements section. Written permission to be acknowledged must be obtained by the corresponding author from all acknowledged individuals. For further information refer to the ICMJE's recommendations on non-author contributors.

Authors may also choose to acknowledge any resources they have used in the development of their article, for example training workshops, online courses, or written materials. 

Cochrane editors as authors

Cochrane editors and editorial staff can author Cochrane Reviews and protocols published in the CDSR. This includes when the Cochrane Review is part of the editor's Cochrane Review Group's (CRG's) portfolio. In line with Wiley's Best Practice Guidelines on Publishing Ethics: A Publisher's Perspective (second edition), the editor or editorial staff member who is an author of the Cochrane Review submitted for publication must:

• exclude themselves entirely from the editorial process to ensure separation of the author and the editorial processes; and
• ensure that another editor or member of the editorial staff takes on these roles.

Special circumstances in the author byline

Group name: Group names may be used in the author byline. All author names must still be listed individually in addition to any group names in the byline.

Joint authors: Cochrane permits joint first or last authors when two or more authors agree to have contributed equally to a review and wish to share the position of first or last author.

Deceased authors: When an individual has made a contribution to a Cochrane Review sufficient to warrant authorship, but has died before publication, that author can remain listed as an author on the published review, if all co-authors agree. Co-authors alternatively may choose to provide an acknowledgement or dedication.

Changes in authorship

Cochrane follows COPE guidance on authorship and contributorship for changes in authorship. In line with their recommendations, all authors, including any author(s) to be removed, must agree in writing with the modification before the author byline can be changed.

Post-publication, including during authoring phase: Authors requesting a change in authorship (modify the order, remove, or add an author) to reviews or updates following the publication of the protocol or previous version of the review, respectively, must submit a completed Changes in Authorship form at submission. The Cochrane Database of Systematic Reviews will also allow corrections to authorship on a published article if a valid reason exists to do so. Please contact Cochrane Support ([email protected]) for assistance.

Pre-publication after submission: Authors requesting a change in authorship (modify the order, remove, or add an author) after they have submitted their article must send a completed Changes in Authorship form to the editor handling their article.

Changes in authorship and Conflicts of Interest: Breaches of Cochrane's Conflict of Interest (CoI) policy cannot be resolved by changes in authorship. This includes modifying the order of authors. Under Cochrane’s CoI Policy for Cochrane Library Content (2020), first and last authors must be free of all relevant conflicts of interest.

Authorship problems and disputes

Cochrane handles any authorship problems and disputes in line with COPE guidance on authorship and contributorship, which addresses scenarios related to authorship including suspected gift, guest or ghost authorship, and manipulation of the publication process.

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Artificial intelligence (AI)-generated content

Author teams who use artificial intelligence (AI) tools, machine learning, language models, or similar technologies when preparing a manuscript for submission to the Cochrane Database of Systematic Reviews must include a statement in the Acknowledgements section, indicating which tool(s) was used, the version (if applicable), and for what purpose. Tools used to improve spelling or grammar are not included in this policy.

In line with the position of COPE and other scientific publications, tools that use artificial intelligence (AI), machine learning, language models, or similar technologies to generate content are unable to fulfil Cochrane's criteria for authorship, and therefore cannot be listed as authors on Cochrane Library publications.

Conflicts of interest

Cochrane defines a conflict of interest (CoI) as a set of conditions in which professional judgement concerning a primary interest (such as patients' welfare or the validity of research) can be unduly influenced (consciously or unconsciously) by a secondary interest (such as financial gain).

This is a summary of key points in the Conflict of Interest (CoI) Policy for Cochrane Library Content (2020). Authors should refer to the policy as a whole when preparing a submission to the Cochrane Library (see Author responsibilities).

The policy applies to all those involved in the creation of Cochrane Library content, defined as the Cochrane Database of Systematic Reviews (Cochrane Reviews, Cochrane protocols, editorials, commentaries and supplements) and Cochrane Clinical Answers. It applies to all new Cochrane Reviews, review updates, and other Cochrane Library content begun on or after 14 October 2020.

For Cochrane Reviews, review updates, and other Cochrane Library content underway or already published before 14 October 2020 the Commercial Sponsorship Policy applies. 

Cochrane’s CoI Policy for Cochrane Library Content requires financial and non-financial interests to be declared and mandates that some conflicts of interest will prevent people from contributing to Cochrane Reviews.

Authors must complete a declaration of interest (DoI) form at the following time points:

• submission of draft article;
• annually until publication;
• just prior to publication.

Funding of Cochrane Library content

• Cochrane Library content cannot be directly funded or produced by any commercial organization with a financial interest in the topic.
• Funders of Cochrane Library content should be declared in the ‘Sources of support’ section of the review or protocol, including a statement that the funder had no role in the design, conduct, or publication of the review, protocol, or update.
• Funders of Cochrane Reviews cannot interfere with review production, that is, the design, conduct, or publication of a review or its update.
• Funding may come from external non-commercial granting bodies such as governments and not-for-profit organizations.

Restrictions on authorship

The following people are prohibited from being an author on Cochrane Library content (relevant timeframes apply; see 'Timeframes' below):

• Anyone who is or has been employed by a commercial organization with a financial interest in the topic of the content
• Anyone who owns a commercial organization with an interest in the topic of the content
• Anyone who personally owns or has applied for a patent related to the topic of the content

In addition, the following restrictions apply to authorship:

• The first and last authors must not have any relevant financial conflicts of interest or have been involved in industry-controlled studies eligible for inclusion in the review. Industry-controlled studies are defined as studies with funding from a commercial organization which is involved in the design, analysis or reporting of the study.
• Overall, 67% (two-thirds) of the authors must be free of relevant conflicts of interest.
• Anyone who has been involved in the conduct, analysis, and publication of a study that could be included in a Cochrane Review cannot make study eligibility decisions about, extract data from, carry out the risk of bias assessment for, or perform GRADE assessments of that study.

Financial interests

Financial interests are relevant if the payment is made by a commercial organization that is developing, or manufactures, markets or distributes (anywhere in the world) an intervention or potential comparator related to the topic of the review or other Cochrane Library content. This applies even if the payment was for work or advice that did not relate to the topic, and (for Cochrane Reviews) regardless of the reported direction of effect. Such payments include (but are not limited to):

• speaker fees, honoraria, consultancies, and membership of advisory boards;
• payment of travel, accommodation, subsistence and conference registration expenses.

In all cases these must be declared, and, in some cases, they may prohibit authorship.

Non-financial interests

Authors must also declare all relevant non-financial interests. Non-financial interests are considered relevant if they have a direct and obvious connection to the topic of the review or other Cochrane Library content.

Timeframes

The relevant timeframe for interests is the period beginning 36 months before article submission and ending at the date of publication.

For authors joining during the process, the relevant timeframe is the period beginning 36 months before the date their involvement began and ending at the date of publication.

Non-adherence

Submissions that do not comply with the CoI policy may not be published in the Cochrane Library.

Published Cochrane Library content that is considered to be in breach of this policy will be referred to the Research Integrity Editors and Conflict of Interest Panel and may be withdrawn from the Cochrane Library.

Cochrane Review Groups and editorial staff employed by Cochrane

The following restrictions apply to Cochrane Review Groups (CRGs), Editorial Board members, and all editorial staff employed by Cochrane.

• No CRG is permitted to accept funding from any commercial organization with a financial interest in the CRG topic area.
• All editorial team members of CRGs, members of the Editorial Board, and editorial staff employed by Cochrane must have NO relevant financial interests.
• Anyone newly appointed to a role in a CRG, to the Editorial Board, or as a member of editorial staff employed by Cochrane must be free of relevant financial interests from the date of appointment.
• All CRG staff, including Co-ordinating Editors, all Editorial Board members, and all editorial staff employed by Cochrane in post on 14 October 2020 who have financial CoI should not sign off reviews of topics relevant to those interests. If they remain in post, they should have divested themselves of those interests within five years and should not acquire any new relevant financial CoI.
• All editorial team members of CRGs, Editorial Board members, and editorial staff employed by Cochrane must complete an annual DoI form.

Governance

Cochrane’s Research Integrity Editors and CoI Panel provide guidance on CoI in the context of Cochrane Library content. Queries about the application of this policy can be made by submitting a referral.

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Reporting and conduct standards

For details of the standards used in the development of Cochrane Reviews, including Cochrane Handbooks and MECIR standards, see: Reference sources and standards.

Cochrane Reviews of interventions

Cochrane has agreed standards for the conduct and reporting of Cochrane Reviews of intervention: Methodological Expectations of Cochrane Intervention Reviews (MECIR) These standards specify the core attributes of Cochrane Reviews on the effects of interventions, and are compliant with PRISMA standards. They provide authors and users of Cochrane Reviews with clear and transparent expectations of review conduct and reporting. Authors and Editors are expected to follow the MECIR standards.

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Plagiarism

Cochrane takes measures to prevent, detect, and address plagiarised content submitted to the Cochrane Library. Submissions to CDSR are expected to be original piece of academic work produced by the listed authors. Material copied from other sources may be used under certain circumstances but should always be acknowledged.

When plagiarism is suspected in a Cochrane Library submission, Cochrane follows applicable COPE flowcharts.

Cochrane uses the World Association of Medical Editors definition of plagiarism: “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 plagiarizer. This applies whether the ideas or words are taken from abstracts, research grant applications, Institutional Review Board applications, or unpublished or published manuscripts in any publication format (print or electronic).

Cochrane uses Crossref's Similarity Check (powered by iThenticate) to carry out similarity checks on all submissions.

There are special circumstances when similarity in text is expected in Cochrane Reviews by the nature of the type of work. These special circumstances may result in Similarity Check finding a high level of similarity of the Cochrane Review text with text from other article(s). High levels of similarity will not always be considered plagiarism.

Special circumstances that will generate high levels of text similarity between Cochrane systematic reviews, versions of Cochrane systematic reviews, and other articles include:

• Similar methods sections
• Cochrane Review Group-specific template used for text in one or more sections (see below)
• Protocol to review, review to update, etc.
• Generic protocol (i.e. two or more reviews based on one protocol)
• Split and merged reviews (i.e. review either split into two or more reviews, or two or more reviews are combined into one review)
• Similarities with published studies (e.g. trials described in the characteristics tables/risk of bias tables)
• Co-publication of a Cochrane Review or protocol or republication in official Cochrane journals or derivative products
• A non-Cochrane systematic review is converted to a Cochrane Review
• Overviews of reviews

Use of text templates

Cochrane Reviews or protocols may make use of templates to ensure that methods are clearly presented. Such reviews may include material that is similar or identical to that in other reviews. Therefore, protocols and reviews that include template text will include a statement acknowledging the use of templates. This statement will be included in the Acknowledgements section.

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Peer review

CDSR is a peer-reviewed publication, which means that all research articles are evaluated by one or more specialists external to the Cochrane Review Group (CRG) editorial team before publication, and the authors have the opportunity to revise the Cochrane Review in response to feedback.

Named peer review

Since January 2019, CDSR has used a named peer review process, whereby the authors and peer reviewer know each other’s names and affiliations during the peer review process.

Consumer peer reviewers are exempt from the named peer review process, and may remain anonymous if they wish to do so. Consumers do still follow the policy for Declarations of potential conflicts of interest for peer reviewers.

If an Editor handling the article believes that the peer review process for a particular Cochrane Review will be significantly negatively impacted by using named peer review, the Editor may apply to the Network Senior Editor or the Editor in Chief for a policy exception on a review-by-review basis.

The names of all peer reviewers who have submitted a peer review report or completed a peer review checklist during the current calendar year are published on the CRG website, unless the peer reviewer has not consented to this. Lists from previous years are be archived and publicly accessible from the CRG website.

Peer reviewers are offered the option of acknowledgement in the Review to which they contributed.

Peer review for particular content types

All new Cochrane Reviews and protocols are peer reviewed.

When a Cochrane Review is updated, selective peer review may be appropriate in some cases, involving only peer reviewers with specific skills or peer review of selected parts of the review, and in other cases no peer review will be required. In all cases the updated Cochrane Review will undergo rigorous assessment by members of the editorial team.

Editorials may be peer reviewed, at the discretion of the Editor in Chief. Published editorials include a 'Provenance and peer review' statement that indicates whether an editorial has been peer reviewed.

CDSR supplements may be peer reviewed, at the discretion of the Editor in Chief. Supplements include a statement to indicate whether the supplement, or sections of the supplement, have been peer reviewed.

Number of peer reviewers

As a minimum standard, every Cochrane Review will be peer reviewed by at least one clinical/topic specialist (with a minimum of one external to the CRG editorial team) and one statistician/methodologist (who may, in some circumstances, be part of the CRG editorial team.

It is expected that CRGs aim to include at least one consumer peer reviewer per Cochrane Review; the Cochrane Consumer Network has more information on this role.

Cochrane Reviews of diagnostic test accuracy (DTA) are peer reviewed before publication. CRGs organize peer review of the DTA Review by consumers and professional specialists; the Cochrane DTA editorial team organize methodological peer review by a methodologist, a statistician, and an information specialist with expertise in DTA review methods. All correspondence with the authors is through the CRG. All revisions must be seen and approved by the DTA editorial team. The final decision on whether the Cochrane DTA Review is ready for publication is made by both the CRG and DTA Editorial Team together; DTA Reviews only progress to publication when both the CRG and the DTA Editorial Team are in agreement.

Post-publication peer review

There is a Comments feature present on all Cochrane Reviews. All comments submitted via this channel receive a response and, if appropriate, the comment and the response from the Cochrane Review author will be published. When necessary, the review will be revised and updated in response to post-publication peer review.

Peer reviewer conduct

Peer reviewers are requested to be aware of, and to follow, the COPE Ethical guidelines for peer reviewers. In summary, peer reviewers should:

• only agree to review manuscripts for which they have the subject expertise required to carry out a proper assessment and which they can assess in a timely manner.
• respect the confidentiality of peer review and not reveal any details of a manuscript or its review, during or after the peer-review process, beyond those that are released by the journal.
• not use information obtained during the peer-review process for their own or any other person’s or organization’s advantage, or to disadvantage or discredit others.
• declare all potential conflicting interests, seeking advice from the journal if they are unsure whether something constitutes a relevant interest.
• not allow their reviews to be in influenced by the origins of a manuscript, by the nationality, religious or political beliefs, gender or other characteristics of the authors, or by commercial considerations.
• be objective and constructive in their reviews, refraining from being hostile or in inflammatory and from making libellous or derogatory personal comments.
• acknowledge that peer review is largely a reciprocal endeavour and undertake to carry out their fair share of reviewing and in a timely manner.
• provide personal and professional information that is accurate and a true representation of their expertise.
• recognize that impersonation of another individual during the review process is considered serious misconduct.

Peer reviewers must declare any potential conflicts of interest every time they undertake peer review of a Cochrane Review.

Peer reviewer reports are owned by the author of the report.

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Data sharing

Cochrane requires, as a condition for publication, that the data supporting the results in systematic reviews published in the Cochrane Database of Systematic Reviews are available for users. Author(s) are required to provide a data availability statement and to confirm, where necessary, that appropriate permissions have been obtained for such use. Analyses and data management are preferably conducted within Cochrane’s authoring tool, RevMan, for which computational methods are publicly available. Scripts and artefacts used to generate analyses outside of RevMan and presented in the systematic review must be publicly archived and cited within the data availability statement of the Review. Most data are shared within the published review directly from RevMan and author(s) are responsible for assessing all data for quality, accuracy and completeness.

For Cochrane systematic reviews, the following is automatically made available and, in most cases, downloadable for users of the Cochrane Library:

• Search strategies for each database (and other sources, if applicable) with search strings, database names, access platforms, search fields and other limitations/settings
• Full citations of each unique report for all studies included, or excluded at the full text screen, in the final review
• Study data, including study information, study arms, and study results or test data
• Risk of bias assessments
• Analysis data, including overall estimates and settings (analysis level), subgroup estimates (mid-level estimates for each subgroup), and individual data rows (all the rows in all the analyses).

For any external data or files, authors should follow the External data and files guidance.

Rejection and appeals

Rejection

A Cochrane Review (new or updated) or protocol can be rejected at any stage before publication.

Cochrane aims to make rejection decisions as early as possible in the editorial process.

The decision to reject is based on one or more of the following domains: topic; quality; timeliness; and policies.

Examples of criteria for a decision to reject a Cochrane Review or protocol:

Topic	The topic of a protocol or review overlaps with existing Cochrane protocols or reviews; editorial decision that the new overlap would not be justified. In the editors' judgement the research question is not suitable or of sufficient importance for a Cochrane Review.
Quality	Authors have not complied with the MECIR standards or other required standards, such as MECIR standards for intervention reviews. A serious problem with the content has been identified and confirmed by an editor. Editors have concerns with the review development process, and the authors have not addressed these to the editors' satisfaction.
Timeliness	Authors have been unable to comply with agreed editorial timelines, without reasonable explanation for the delay.
Policy	Authors have not declared relevant competing interests or have declared competing interests that contravene Cochrane's Conflict of Interest policy. There is an unresolved, published 'Expression of Concern' about the previously published version (e.g. on the protocol if the current manuscript is for the review, on the review if the current manuscript is for an update). The manuscript contravenes one or more of Cochrane's editorial policies.

Rights in Cochrane Reviews rejected before publication

Authors’ rights: If a Cochrane Review is rejected at any stage before publication, the authors’ rights in the unpublished review are unchanged, and the authors can use the content elsewhere (such as for publication in a journal, or for research purposes), on the condition that the work is not titled, described, or referred to as a 'Cochrane Review'.

Cochrane’s rights: Cochrane will retain a copy of the rejected Cochrane Review submission for archival purposes. Cochrane retains the rights to the elements within a rejected submission that were developed by Cochrane, such as the search strategy and templates. Cochrane may publish a Cochrane Review using elements developed by Cochrane for the rejected review and may use the same title and address the same question as the rejected review. This will be an entirely new work and, potentially, an entirely new author team.

Appeals

Any disagreement with the decision to reject will be considered according to the Cochrane appeals policy and process.

If authors disagree with an editorial decision to reject a specific Cochrane Review, they may appeal the decision.

Appeals are considered on the basis of:

• error(s) in the editorial process (the correct editorial procedure or Cochrane policy has not been followed), or
• error(s) in the decision (the correct process has been followed but there has been an error in interpretation or understanding).

Only one appeal will be considered.

For more information see Appeals process.

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Co-publication

Cochrane has a co-publication policy in place which enables the publication of Cochrane Reviews in other journals. This is permitted in certain circumstances to support the dissemination of the findings of Cochrane Reviews. In general, the journal for the co-publication is likely to be a specialist publication (and therefore reaching a specialist audience) or published in a language other than English (reaching a wider audience). The underlying principles that govern co-publication include the following:

Honesty and transparency are crucial, for example between the editorial teams of the Cochrane Review Group (CRG), the review authors, and journal editors/publishers, and also to inform the reader that different versions of the same data exist.

The needs of end users are the prevailing consideration but the wellbeing of Cochrane, the Cochrane brand, and the CDSR are also crucial to any decision.

Cochrane Review authors and CRG editorial teams who have contributed to the development of a Cochrane Review should be involved in any decision-making in relation to co-publication, and co-publication requires the permission of all the authors on the by-line of the Cochrane Review.

The primary publication of a Cochrane Review (and subsequent updates) is in the CDSR; any exception to this requires permission from the Editor in Chief.

All co-publication of Cochrane content needs to be consistent with the guidance of the International Committee of Medical Journal Editors (ICMJE), particularly regarding overlapping publication.

Co-publications may take one of the following forms:

• Short version of the review (the abstract and/or Plain Language Summary and/or an abridged version of the review content) on its own.
• As above alongside an accompanying original commentary/article.
• Short version of the review alone translated into a specific language with option of including it in English (language of original publication) also.

Post-publication co-publication refers to requesting to co-publish an abridged Cochrane Review in another journal after it has first been published in the CDSR. The standard type of co-publication would be post-publication. There may be instances when the public would benefit from the publication of a co-published version of a Cochrane Review in both the CDSR and another journal on the same day. Same-day publication is subject to approval by the Cochrane Editorial & Methods Department.

Requirements for co-publication

When considering submitting an article to another journal to be co-published, author teams are asked to ensure that the following requirements are met:

1. Authors must ensure to make a complete statement to the journal editor so they are aware that a submission is based on a Cochrane Review and should share the permission to co-publish form with the journal Managing Editor once it is completed.
2. The journal version must faithfully reflect the data and interpretations of the Cochrane version. Where journal editing and peer review have resulted in differences in the data or interpretation, these should be discussed with the CRG, and, where appropriate, incorporated into a revised version of the Cochrane Review at the next available opportunity, and with appropriate acknowledgement to the journal’s peer reviewers/editors.
3. The title of the journal version should indicate that it is a secondary publication of the Cochrane Review, preferably by including 'Cochrane Review' or 'Cochrane Systematic Review' in the title.
4. The support of the CRG in publishing the Cochrane Review should be acknowledged in an appropriate place in the journal version (e.g. in the Acknowledgements section).
5. The Cochrane Review must be cited in the reference list of the journal version.

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Copyright and licence for publication

Authors of Cochrane Reviews (including updates and protocols for a Cochrane Review) and Editorials are required to sign a licence for publication each time a new citation version is prepared.

Publication in the CDSR will proceed only once all authors have signed the licence for publication form.

When an author’s contributions are owned by the author’s employer (e.g. WHO, PAHO) an addendum must be signed. Any other involvement from an external institution (e.g. funding, commissioning) does not require an addendum to be completed but may require acknowledgment elsewhere in the review or protocol.

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Updating Cochrane Reviews

An update of a Cochrane Review must involve a search for new studies. If any new studies are found, these must be added to the relevant section of the Cochrane Review and classified as included, excluded, or ongoing studies (or ‘Studies awaiting classification’ if all reasonable efforts to classify it in one of these ways have failed), before labelling the revised Cochrane Review as an update. Any other change to a Cochrane Review, and any change to a Protocol for a Cochrane Review, is classified as an amendment.

A Cochrane Review should be updated based on need. Aspects to consider are the currency of the question, the impact and usage of the current version, the availability of additional studies (or additional data for studies already included), and an assessment of the likely change of any newly identified studies or additional data on the current review version; in addition to methodological enhancements that may be required.

Updated Cochrane Reviews acknowledge and cite the previous versions of the same Cochrane Review

Authors need to complete a new licence for publication and declare relevant conflicts of interest for each update.

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Comments and complaints

Comments on the content of a Cochrane Review, Protocol or Editorial can be submitted via the Cochrane Library. Concerns about policies, processes, or actions can be raised with the Editor in Chief through the complaints procedure.

Comments

Cochrane welcomes comments on Cochrane Reviews, protocols or Editorials published in the CDSR. Comments are welcome from all users of the Cochrane Library, including patients and consumers. Comments should be submitted via the Cochrane Library and may be published on the Cochrane Library.

See Submitting comments

Complaints

Complaints could apply to the policies, processes, or actions of staff, contributors or position-holders within Cochrane who are involved in the publication or content of the Cochrane Library. Cochrane welcome complaints as they provide an opportunity for improvement, and aims to respond efficiently and constructively.

Complaints are defined as an expression of unhappiness about a failure of process or an important misjudgement. The Editor in Chief of the Cochrane Library is responsible for this complaints procedure and will respond to queries about it.

See: Cochrane Library complaints procedure

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Managing potentially problematic studies

Cochrane Reviews are high quality systematic reviews that aim to provide the best available evidence of the effects of healthcare interventions. The Cochrane Review process is robust and methodologically mature, but the quality of the evidence produced depends, inevitably, upon the reliability of the studies included. The Cochrane policy for managing potentially problematic studies details what Cochrane Review authors and editors should do when serious concerns are raised about the trustworthiness of included studies.

Definitions

Cochrane Review: the term ‘Cochrane Review’ refers to the published stages of a review, including the protocol, review, and any updates. The term also covers overviews, prognosis reviews, reviews of diagnostic test accuracy (DTA), and other review formats. Problematic study: there is currently no universally accepted definition of a problematic study. For the purposes of this policy, the term refers to any published or unpublished study where there are serious questions about the trustworthiness of the data or findings, regardless of whether the study has been formally retracted. Scientific misconduct will not be the only reason that a study might be problematic; problems may result from poor research practices or honest errors. Post-publication amendment: a note added to a published article to correct, withdraw, or raise concerns about the findings reported. Types of post-publication amendment include: Errata/Corrections, Retractions, Expressions of concern, Editorial notes. Retraction: this policy uses the Committee on Publication Ethics (COPE) definition of retraction, namely: “a mechanism for correcting the literature and alerting readers to articles that contain such seriously flawed or erroneous content or data that their findings and conclusions cannot be relied upon. Unreliable content or data may result from honest error, naïve mistakes, or research misconduct.”.

 

Concerns may arise about the validity of data in an included study, or a study eligible for inclusion while a Cochrane Review is being conducted, or after publication. Such concerns may arise due to publication of a post-publication amendment for an included study, or where Cochrane Review authors and/or Cochrane Review Groups (CRGs) identify concerns about the trustworthiness of the data for included studies without formal post-publication amendments. This policy covers managing such problematic studies, including:

• studies that have been formally retracted;
• studies that have a published Expression of Concern;
• studies with no formal post-publication amendment, but where Cochrane authors or editors have concerns about the trustworthiness of the study data.

This policy does not cover cases where concerns are raised about the conduct or reporting of a Cochrane Review itself. For more on this see Allegations of misconduct

Future developments

There is currently no standard definition of – or a validated method to identify – a problematic study that has not been identified as such through a post-publication amendment. Cochrane appreciates this is an area where further guidance is needed; this policy and the accompanying resources will be revised and updated as empirical evidence becomes available and consensus emerges in this area.

Cochrane authors and CRGs may encounter studies with no post-publication amendments concerning retraction, or Expressions of concern, for which they have serious concerns about the trustworthiness of the data. Until a validated method to identify problematic studies is developed, this policy and the accompanying Implementation Guidance explain Cochrane’s policy on how such studies should be managed.

Roles and responsibilities

All CRGs are expected to take steps to minimise the risk of including problematic studies in Cochrane Reviews. These steps include:

• ensuring that the search strategy for a Cochrane Review includes searches for any post-publication amendments to studies (See MECIR C48);
• acting on any concerns identified by the review authors or CRG members about the trustworthiness of a study;
• not including studies in a review until any serious concerns about their trustworthiness (from review authors or CRG members) have been resolved. These studies can be placed in the Awaiting classification section;
• recording any information of concern appropriately.

If there are questions about the trustworthiness of an included study (or one that is eligible for inclusion) in a Cochrane Review, steps should be taken to ensure that the study is acceptable for inclusion. Recommended steps for this are detailed in the Implementation Guidance. Any concerns about a study must be resolved before the study data can be included in a Cochrane Review.

If a CRG employs its own criteria for the inclusion and/or exclusion of studies (in line with the Cochrane Handbook policy), these criteria must be available from the CRG website.

It is not within Cochrane’s remit to conduct a formal investigation, or to draw formal conclusions regarding the misconduct of an individual or group of individuals, or to determine whether a published article should be retracted. That role belongs to the employer, university, granting agency, regulatory body, or journal editor concerned. Cochrane does, however, have a responsibility to protect the integrity of the public scientific record by sharing reasonable concerns with authorities that can conduct such an investigation (including journal editors).

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Allegations of misconduct

For handling allegations of misconduct in Cochrane Reviews, Cochrane follows the Committee on Publication Ethics (COPE) guidelines and flowcharts. All cases of suspected or proven misconduct will be assessed fairly and decisions are transparent. Relevant institutions or authorities may be informed as applicable.

Allegations of research misconduct will be investigated by the Editor in Chief's office. Concerns may include doubts about the scientific accuracy or validity of a Cochrane Review, the integrity of the review authors, instances of plagiarism, figure manipulation, peer review manipulation and other forms of misconduct. Whenever possible, the confidentiality of whistle-blowers will be protected, whether those are internal or external to Cochrane.

In accordance with COPE guidance, Cochrane reserves the right to contact the institution, funders, or regulatory bodies of Cochrane authors for obtaining additional information or raising concerns. Cochrane may also seek advice on difficult cases by submitting anonymous cases to COPE forums for advice. If a concern is confirmed, Cochrane will ensure prompt correction or amendment of the Cochrane Review or protocol of concern.

Concerns of research misconduct should be referred directly to the Editor in Chief and will be investigated thoroughly by a non-conflicted Senior Editor. Concerns should be as factual as possible and should include specific examples to facilitate the investigation process.

COPE guidance, including flowcharts, guidance documents, and insights from resolved cases, will be followed as much as possible. While the procedure may change depending on the concern at hand, concerns will always be treated with respect for the confidentiality of authors and those raising the concern.

In line with COPE guidance the wish to retain anonymity by whistle-blowers will always be respected whenever possible, whether raised directly or via social media.

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Withdrawal of published articles

Cochrane Reviews

Cochrane Reviews are withdrawn when serious issues with conduct or reporting are identified.

Reasons for withdrawing a Cochrane Review or protocol:

• Serious error in a Cochrane Review. Following the conclusions of the published review could result in harm to patients or populations of interest (other than known adverse effects); and/or there are factual errors in describing one or more included studies that risk misinforming implementation or investment decisions about an intervention; and/or the reported treatment effect is inconsistent with the real effect shown in the reported data.
• The conclusions of a Cochrane Review are unreliable as a direct result of the retraction of an included study. This could occur if a study, or studies, included in a Cochrane Review are retracted from publication, and an analysis shows that the removal of the retracted studies from the analyses in the Cochrane Review has a major effect on the review. Also see: Cochrane policy on managing potentially problematic studies.
• Research misconduct in the Cochrane Review. This refers to misconduct during the conduct or reporting of the Cochrane Review.
• Serious breach of Cochrane’s conflict of interest policy. A ruling by Cochrane’s Research Integrity Editors and CoI Panel that a Cochrane Review has seriously breached Cochrane’s conflict of interest policy.

Withdrawing a Cochrane Review generates a new version of the review with a new DOI. The withdrawn content remains accessible via the version history.

Prior to July 2019, Cochrane Reviews were withdrawn for other reasons (e.g. the review no longer represented the best current evidence or it was superseded by another systematic review). Prior to March 2022, protocols were also withdrawn to inform readers that a protocol would not be progressed to the review stage. This is now indicated by the addition of an Editorial note to the protocol.

Withdrawal followed by republication

The Editors may accept for publication a revised version of a Cochrane Review that addresses the issues raised in the withdrawn notice. Any such version will be re-evaluated using standard Cochrane editorial process, and may then be approved for publication (as a separate, subsequent version) by the Editor in Chief in consultation with the Network Senior Editor.

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Publishing model and open access

All Cochrane Reviews are free to view 12 months after publication and all protocols are free to view immediately upon publication. Authors also have the option to publish with a Creative Commons licence, which enables immediate open access and other benefits, upon payment of an APC or via a fee waiver for eligible author teams (via gold open access).

All Editorials are free to view immediately upon publication. Authors also have the option to publish with a Creative Commons licence, which enables immediate open access and other benefits, upon payment of an APC or via a fee waiver for eligible author teams.

For more information, see open access.

Cochrane supports article sharing in line with the STM article sharing framework. For more information on the options for sharing an article published in the CDSR please visit howcanishareit.com.

Authors have the right to post the published version of their Cochrane Review or protocol for a Cochrane Review in a repository, 12 months after publication. A repository is an online archive of a research institution for the collection preservation and dissemination of digital copies of its authors’ intellectual output.

PubMed Central

Cochrane Reviews and Protocols may be submitted and included in PubMed Central or PMC Europe through one of the following routes:

• Articles published with standard licence (green open access)
• Articles published with a Creative Commons licence (gold open access)
• USA National Institutes of Health (NIH) funded research
• UK National Institute for Health Research (NIHR) Programme Grants

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Date updated: 7 March 2024