Since April 2012, all updated Cochrane Reviews receive a new citation so that the wording of the abstracts is always consistent between the CDSRand MEDLINE and other databases; see What's New events for Cochrane Reviews. 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 review 'History' alongside the published Cochane Reviews).