Peer review is a term that describes the objective evaluation of clinical and scientific research, usually (but not restricted to) before publication. All new Cochrane Reviews undergo peer review, and most updates of Cochrane Reviews also undergo peer review. For further information, see Cochrane peer review policy statement.
Protocols for Cochrane Reviews are peer reviewed to ensure that the research question is valid, the methods suggested are appropriate, and to avoid duplication of effort. Editors may use peer review reports to ensure that resources are allocated appropriately; for example, to prioritise protocols that answer the most relevant questions. Protocols for Cochrane Reviews may be rejected before or after peer review; for example, if the topic is not relevant or not suitable for a review, if the methodology is unsound, or if there are other major issues with the protocol.
Cochrane Reviews are peer reviewed to ensure that they follow the published Cochrane Protocol (or any deviation from the published protocol is sufficiently explained); the research question is still valid, to identify whether any relevant and important studies have been excluded, the clinical context is correct and up-to-date, the methodology is appropriate and that the conclusions are based only upon the data available. Cochrane Reviews may be rejected before or after peer review; for example, if the methodology is unsound, or if the authors are unable to revise the review to the satisfaction of the Cochrane Review Group Editor(s). For more information, see the policy on the rejection of Cochrane Reviews.