Medicine is characterised by uncertainty and many treatments in use today have never been properly evaluated. At the same time new treatments are slow to be implemented.
Centres such as the NHS Centre for Reviews and Dissemination and the UK Cochrane Centre are now reviewing the evidence on effectiveness of treatments and disseminating the findings to clinicians, managers and patients through, for example, bulletins, journals and databases but it is a major task.
The Cochrane Library, which incorporates evidence from both the NHS Centre for Reviews and Dissemination and the Cochrane Collaboration, is the best available source of evidence about the effects of health care. The Cochrane Library is a collection of databases, published on CD-ROM and updated quarterly, containing the Cochrane Database of Systematic Reviews, the Cochrane Controlled Trials Register, the Database of Abstracts of Reviews and Effectiveness, the Cochrane Review Methodology Database and information about the Cochrane Collaboration.
A network of centres of evidence based medicine are planned as part of the NHS R&D Programme. The first of these was the Centre for Evidence Based Medicine in Oxford followed by the National Centre for Evidence Based Child Health which opened in London in 1995. Health authorities are increasingly looking to evidence of clinical effectiveness (which interventions really work) to support their purchasing decisions.