Evidence is included or excluded on the basis of explicit quality criteria to minimize bias.
DARE also contains references to other reviews which may be useful for background information. More information about DARE can be obtained from the NHS Centre for Reviews and Dissemination home page. CCTR is a bibliography of controlled trials identified by contributors to the Cochrane Collaboration and others, as part of an international effort to hand search the world's journals and create an unbiased source of data for systematic reviews. Access to Cochrane is controlled by your computer's identifying IP number. Only persons identified as associated with UNM are permitted access.