Via the Cochrane Database of Systematic Reviews
The CDSR includes an archive of all citation versions of published Cochrane Reviews (including Protocols) starting from Issue 4, 2003 (www.cochranelibrary.com). Where previous versions of a Cochrane Review exist in the CDSR, these can be accessed via the ‘Other Versions’ link on each Cochrane Review.
All published versions of Cochrane Reviews (including Protocols for Cochrane Reviews) are stored on the Cochrane central server, Archie. This also includes versions published before the launch of Archie in 2005–2006. The published versions stored in Archie cannot be deleted. Archie also contains versions of draft Cochrane Reviews that are not published.
Full access to the archive of all published Cochrane Reviews in Archie is available only to a few individuals in each Cochrane Group, such as Cochrane Review Groups (CRGs), as well as Archie ‘Super Users,’ and system and data administrators. This access to the archive can help CRG editorial teams answer queries about previously published versions that are not available in the public archive through the Cochrane Database of Systematic Reviews (CDSR) (see below). However, it is at the discretion of the CRG editorial teams as to whether they choose to provide copies of Cochrane Reviews to people who have asked for them.
Using the archive data for methodological purposes
Researchers who are proposing to use the archived data for methodological purposes can also apply for permission for access to all previously published reviews by completing a Reviews and methods data request form. These requests are escalated to Cochrane’s Editor in Chief and Chief Information Officer for approval. If permission is granted, Cochrane will assist in providing these data, but there may be a cost for this service, depending on the complexity of the request.