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Assessing reviews for updating

An update of a Cochrane Review must involve an updated search and the incorporation of any new studies (see Cochrane policy). 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.

We routinely assess our reviews around two years after publication, unless otherwise agreed at publication (see below). From January 2017, our policy is to assess overviews for updating every five years rather than every two, unless otherwise agreed. This accounts for the length of time it takes to develop and publish Cochrane/systematic reviews that may be included in the overview.

We rely on the expertise of the authors and editors in assessing a review for updating, as well as the Cochrane Updating Classification System and the Updates Classification Flowchart. A full or restricted search is required before we can apply the classification, which provides the following three options.

1. No update planned, e.g. intervention no longer in use/superseded (also referred to as a 'stable' review).
2. Up to date, e.g. no new studies identified; new studies identified but unlikely to change conclusions (sometimes referred to as a 'stable' review). 
3. Update pending, e.g. new studies likely to change conclusions have been identified.

Any decision about the updating status of the individual review will be made in collaboration with the authors and editors. If the original author team is unavailable, PaPaS will make an editorial decision based on an updated search.

For options 1 and 2, the Managing Editor will guide authors through the process for making their review stable. A review can be stabilised permanently (option 1), or for a specific number of years (option 2). Before publication of a new review, it is our policy to discuss with authors whether we can stabilise directly upon publication; this relates to option 2 and allows us to stabilise a review for X years if we know the research area is not very active, or there are ongoing studies that are unlikely to be published for X years.

For option 3, the update development process will be initiated. Authors will be sent the latest Cochrane guidance as it is likely that standards will have changed since the last review version. We will also check that the team meets the requirements of the Cochrane Commercial Sponsorship policy. Our Information Specialist will perform full searches if necessary, e.g. only a restricted search was run earlier. 

To ensure a high-quality product in accordance with Cochrane standards, the editorial team will complete validation checks and minor copy editing amendments. We compare the update against the protocol to check for any differences, and we check for adherence to the Cochrane Style Manual, Cochrane Handbook and MECIR Standards. We will ask for the review to be revised if these standards are not met. See our "Useful links" page for more information, and our "Step by step" page for details of the update development process. Cochrane provides a range of information, resources and training covering the steps involved in conducting a Cochrane Review (see our "Useful links" page).