Guidelines for Reviewers

PLOS Medicine relies on members of the scientific research community to assess the validity of articles under consideration through peer review.

Invitation to Review

PLOS Medicine editors select potential reviewers based on their expertise in research areas relevant to the manuscript under consideration. Reviewer invitations are sent by email from the journal's Editorial Manager submission system. Use the links in the invitation email to accept or decline, or check the “New Reviewer Invitations” folder on your Reviewer Main Menu screen in Editorial Manager. Accept an invitation only if you have the knowledge, time and objectivity necessary to provide an unbiased assessment of the research. In agreeing to complete a review, you also give permission to publish your review under a Creative Commons Attribution CC BY license.

Our Peer Review Process

PLOS Medicine practices single-anonymized peer review by default, but offers opportunities for authors and reviewers to participate in signed and published peer review.

Our peer review model

	Single-anonymized peer review During the peer review process you will know the authors’ names, but your name will not be shared. Your review will appear in the editorial decision letter where it can be read by the authors and other reviewers.
	Signed peer review You can choose to sign your name to your review when you submit it. Remember, if you sign your name the authors and other reviewers of the manuscript will see it. If the authors choose to publish their peer review history your name will accompany your comments alongside the published article.
	Portable If the authors subsequently choose to transfer their manuscript to another PLOS journal your review will accompany it. You may hear from editors at another PLOS journal for re-review. Reviewers for any PLOS journal should be willing to have their reviews considered by the editors of another PLOS journal.
	Published peer review history If the authors decide to publish their peer review history, the editorial decision letter, including your review, will appear alongside the published article. Your name will not appear unless you choose to sign your review.

Best practices for reviewers

	Declaring competing interests A competing interest is anything that interferes with or could be perceived as potentially interfering with, a thorough and objective assessment of a manuscript. Common examples of competing interests may include: A recent or current collaboration with any of the authors Direct competition or a history of scientific conflict with any of the authors An opportunity to profit financially from the work Do not accept a review assignment if you have a competing interest, or don’t feel able to give an objective assessment. If you’re unsure whether your relationship qualifies as a competing interest, contact the journal office for advice. If we ask you to complete the review anyway, be sure to declare the competing interest when you submit your review.
	Crediting collaborators If you had help completing the review you must share your collaborator’s name with the journal via email. Be careful not to include your collaborator’s name in the text of the review itself.
	Confidentiality Keep manuscripts and correspondence confidential and do not share information about submissions with any one else unless previously agreed with the editor. We expect that reviewers will not make use of any material or take advantage of any information they gain through the peer review process. Read the PLOS Confidentiality Policy.
	Reviewing a manuscript you’ve previously reviewed If you reviewed the article at another journal, consider the manuscript as a new submission unless instructed otherwise. Keep in mind that it may have been revised since the last time you evaluated it, and PLOS Medicine’s criteria for publication may differ from those of the other journal. When you submit your review, let the editor know that you reviewed a previous version of the manuscript at another journal.
	Time to review Aim to complete your review within 8 days. If you need more time to perform the review, please email us as soon as possible.

Receiving credit

In choosing to volunteer as a peer reviewer for PLOS, you are helping to support free and open access to rigorous research. We couldn’t be more grateful!

Reviewer Credit with ORCID and Publons

Link your PLOS reviewer account to your ORCID or Publons record. Set up syncing to have reviewer activity automatically posted to your ORCID profile review activity. This record will confirm that you completed a review for the journal, but won’t publish the content of your review.

Submit Your Review Now

Learn About Peer Review

What to Assess

To be eligible for publication manuscripts must meet our criteria for publication and comply with our editorial and publishing policies. The following guidance relates to articles reporting the results of original research. If you are reviewing another article type see the other article types page and check your invitation letter for guidance on what to consider in your review.

Criteria for publication

In addition to being conducted in accordance with ethical standards and scientifically valid, research published in PLOS Medicine should fulfill each of the following criteria:

The research question is an important one to the community of researchers in this general area.
The results provide a substantial advance over existing knowledge, with clear implications for patient care, public policy, or clinical research agendas.
Published together with an Author Summary written for general readers, the article is of interest to clinicians and policymakers who are not specialists in this topic.

Writing the review

The purpose of the review is to provide the editors with an expert opinion regarding the validity and quality of the manuscript under consideration. The review should also supply authors with explicit feedback on how to improve their papers so that they will be acceptable for publication in PLOS Medicine. As you write, consider the following points:

What are the main claims of the paper and how significant are they for the discipline?
Are the claims properly placed in the context of the previous literature? Have the authors treated the literature fairly?
Do the data and analyses fully support the claims? If not, what other evidence is required?
PLOS Medicine encourages authors to publish detailed methods as supporting information online. Do any particular methods used in the manuscript warrant such publication? If a protocol is already provided, for example for a randomized controlled trial, are there any important deviations from it? If so, have the authors explained adequately why the deviations occurred?
Is this paper outstanding in its discipline? If yes, what makes it outstanding? If not, why not?
Does the study conform to any relevant guidelines such as CONSORT, MIAME, QUORUM, STROBE, and the Fort Lauderdale agreement?
Are details of the methodology sufficient to allow the experiments to be reproduced?
Is any software created by the authors freely available?
Is the manuscript well organized and written clearly enough to be accessible to non-specialists?

Although confidential comments to the editors are respected, any remarks that might help to strengthen the paper should be directed to the authors themselves.

Revisions

We often ask the original reviewers to evaluate revised manuscripts and the authors’ response to reviewer comments. We hope that you’ll make yourself available for re-review and questions from the editors.

Editing reviewers’ reports

The editors and PLOS staff will not change any reviewer comments that are intended for authors to read, except with reviewer approval prior to the decision letter being sent. For example, we may request changes if language is deemed inappropriate for professional communication, or if the comments contain information considered confidential, such as competing interest declarations.

The Editorial Process

Decision process

The editors make the final decision on whether to publish each submission based on the reviewers’ comments, the PLOS Medicine criteria for publication, and their own assessment of the manuscript.

Conflicting reviews

If reviewers appear to disagree fundamentally, the editors may choose to share all the reviews with each of the reviewers and request additional comments that may help the editors to reach a decision. Decisions are not necessarily made according to majority rule. Experts may disagree, and it is the job of the Editor to make a decision. Editors evaluate reviewer recommendations and comments alongside comments by the authors and material that may not have been made available to reviewers. Please know that your recommendation has been duly considered and your service is appreciated, even if the final decision does not accord with your review.

Help

For more tips on peer review go to the Peer Review Center, and sign up to the Peer Review Toolbox.

If you have questions or concerns about the manuscript you are reviewing, or if you need assistance submitting the review, please email us plosmedicine@plos.org.