The Cochrane Library is an electronic publication designed to supply high quality evidence to inform people providing and receiving care, and those responsible for research, teaching, funding and administration at all levels. The Abstracts of Cochrane Reviews are available without charge and can be browsed or searched . A rapidly growing collection of regularly updated, systematic reviews of the effects of health care, maintained by contributors to the Cochrane Collaboration. New reviews are added with each issue of The Cochrane Library. Cochrane reviews are reviews mainly of randomised controlled trials.
Evidence is included or excluded on the basis of explicit quality criteria to minimise bias.
Data are often combined statistically, with meta-analysis, to increase the power of the findings of numerous studies each too small to produce reliable results individually. The review thereby continues to be the best single place where a distillation of the latest evidence is easily accessible. 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.