The amount of literature on the effectiveness of health care is enormous, and is increasing rapidly. It is impossible for health care providers to keep up to date by reading all reports of original research. Therefore there is a need to review all primary research. The late Archie Cochrane, famous for his influential book: Effectiveness and Efficiency, Random Reflections on Health Services, emphasised this need by stating:
It is surely a great criticism of our profession that we have not organised a critical summary, by specialty or subspecialty, adapted periodically, of all relevant randomised controlled trials.
Archie Cochrane
There is a need for methodologically sound meta-analyses as a way of reviewing. Unfortunately, the quality of the reviews from the past has left much to be desired. This is because often reviewers have not approached their task systematically, with respect to scientific principles. As a result, advice on some lifesaving therapies has been delayed for more than a decade, while other treatments have continued to be recommended long after controlled research showed them to be ineffective or actually harmful.
State of the art reviews which summarise all available evidence from randomised controlled clinical trials (RCTs) are necessary for the provision of the most optimal health care by clinicians and health care workers, the decisions of policy makers and financiers of health care and for future planning of relevant new research.
Systematic reviews need to be produced and have to be kept up to date. This continuous task cannot be done by one or two persons, but requires the co-operation of interested and enthusiastic individuals from all over the world.
The Cochrane Collaboration encourages groups of people to start collecting and reviewing all RCTs (or if not available other reliable evidence) on a specific topic or health problem.
The Cochrane Collaboration consists of review groups, fields and centres.
Review groups are responsible for providing and keeping an up to date overview of the available evidence on a specific health problem.
Fields are concerned with disciplines and specialties in health care. Their purpose is to ensure that, by wide and appropriate consultation, all the important topics which come to the attention of the fields are covered by review groups.
Cochrane centres share a responsibility for helping to co-ordinate and support the Cochrane Collaboration. Their role is broad and includes helping collaborators and contributors to reviews groups; maintaining a register of collaborators and reviews; developing protocols and software, policies and standards; promoting research to improve the generation of reviews and general co-ordination, support and guidance of the Cochrane Collaboration.