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.
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.
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.