Cochrane Central Register of Controlled TrialsThe Cochrane Central Register of Controlled Trials (CENTRAL) is a highly concentrated source of reports of randomised and quasi-randomised controlled trials. The majority of CENTRAL records are taken from bibliographic databases (mainly MEDLINE and Embase), but records are also derived from other published and unpublished sources. In addition to bibliographic details (author, source, year, etc.) CENTRAL records will often include an abstract (a summary of the article). They do not contain the full text of the article.