Editorial and Publishing Policy Resource
Cochrane Review updates

Definition of an updated Cochrane Review

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 an amendment, which could involve a little or a lot of work.

These definitions are from Chapter 3 of the Cochrane Handbook for Systematic Reviews of Interventions.

Frequency of updating Cochrane Reviews

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.

Refer to the Updating Classification System to help assess and report on the updating status of an individual Cochrane Review.

Living systematic reviews

Cochrane is exploring the feasibility of producing and publishing living systematic reviews (LSRs). Living systematic reviews offer an approach to review updating in which the review is continually updated, incorporating relevant new evidence as it becomes available. The first pilot LSRs are expected to be available on the Cochrane Library in 2017. This work is being led by Cochrane's Project Transform with support from the LSR Network. For more information about Cochrane's LSR pilots, including the interim guidance document for conducting LSRs, see Living Systematic Reviews.

Citation of updated Cochrane Reviews

Since April 2012, all updated Cochrane Reviews receive a new citation so that the wording of the abstracts is always consistent between the CDSR and MEDLINE and other databases. This applies to all updated Cochrane Reviews because at the very least any update will include a new ‘search date’. Citations to updates should be given even when a new search reveals no new trials, and when there are no edits made to the Cochrane Review apart from updating the search. Every time a Cochrane Review receives a new citation, the previously cited version is archived in the CDSR alongside the current version (see the ‘Other Versions’ tab).

Selecting ‘What’s new’ events for updates to Cochrane Reviews

Two ‘What’s new’ events must be selected for Cochrane Review updates in Review Manager (RevMan); see Table 1.  The first is ‘Updated’. The second depends on whether the review conclusions have changed following the update (‘New citation: conclusions changed’ or  ‘New citation: conclusions not changed’).

Table 1. Selecting the two ‘What’s new’ events in RevMan for Cochrane Review updates

Types of updates

RevMan event 1

RevMan event 2

Cochrane Review update and conclusions changed


New citation: conclusions changed

Cochrane Review update and conclusions not changed


New citation: conclusions not changed

Acknowledging previous versions of the review within an updated review

Updated Cochrane Reviews should acknowledge and cite the previous versions of the same Cochrane Review in the section ‘Other published versions of this review’ in RevMan, and the Cochrane Review text should reference the citation and make clear to readers that a previous version or versions have been published. The need for transparency in the publishing record of a Cochrane Review highlights the importance of citing every updated Cochrane Review so that there is a permanent record available to readers in the CDSR.

Licence for publication and declaration of interests forms

Authors need to complete a new licence for publication form and declaration of interest form each time an update is published.


Also see 'Changes to citation and author contact details in published Cochrane Reviews'.

Section info
Describe change
Added information about living systematic reviews.
Change date
26 June 2017