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research are unlikely to have a high ticular research questions. This is why become dated and irrelevant. Because of number of clinically based trials direct the evidence-based supplement will also this we will seek to both review our core ed towards them. Equally journals endeavour to include these when appro list regularly and also look beyond this which publish qualitative research are priate and well conducted. list. If any reader feels any particular disadvantaged in a table based on ran It is equally important that only well article is important and should be domised-controlled trials or systematic conducted and reported randomised included please feel free to contact the review. However rating journals on the controlled trials or systematic reviews editorial office with the reference. We basis of their number of citations is are included. If we were to look in detail will then include it in our review equally open to challenge as noted at both the randomised-controlled tri process. Provided it passes the quality above. als and systematic reviews identified by filters it will appear in the supplement. Well-conducted randomised -con- the search strategy above many would trolled trials and systematic reviews not meet our quality criteria (see page Acknowledgements based on them have great potential for 32). This supplement will endeavour to To Christine Allot, Librarian, at the Berkshire Health Authority who conducted the answering questions about whether a include only good quality articles relat medline searches. treatment does more harm than good ing to treatment, diagnostic testing, particularly in the clinical situation. screening, prognosis, economic analyses Therefore a rating process based on the and guidelines that meet predefined cri 1 Montgomery J. BDJ readership survey. Br numbers seems more appropriate. teria. Dent J1998; 184: 563-564. 2 Haynes R B, McKibbon K A, Fitzgerald D, However, if we only consider journals Our aim will be to bring to the prac Guyatt G H, Walker C J, Sackett D L. How to based on randomised-controlled trials tising dentist summaries of the best keep up with the medical literature: II. or systematic reviews we will miss many available dental literature based on a Deciding which journals to read regularly. good quality research articles which use core list of journals producing the great Ann lnt Med 1986; 105: 149. a qualitative approach. Qualitative est yield of useful papers. However it 3 Sackett D L S, Haynes R B, Guyatt G H, Tugwell P. Cl(nical epidemiology, a basic research is very important and qualita will not restrict itself to that list. Any science for clinical medicine, 2nd edn. tive research designs are often the most core list of journals or books that are Boston: Little, Brown and Co., 1991. appropriate method of answering par- accepted unquestioningly quickly
The Cochrane Collaboration: an introduction P. Alderson 1
pregnancy and childbirth as 'a real This brief introduction to the work of the Cochrane Collaboration is an abridged milestone in the history of randomised version of the full text appearing in The Cochrane Collaboration Brochure available trials and in the evaluation of care', and from the following web site: suggested that other specialties should copy the methods used. 3 In the same http:/ I som.flinders.edu.au/fusa/ cochrane.html year, the scientific quality of many pub lished reviews was shown to leave much to be desired.4 As Cochrane had In 1972, 1 Archie Cochrane, a British do not have ready access to reliable emphasised, reviews of research evi epidemiologist, drew attention to our reviews of the available evidence. In dence must be prepared systematically great collective ignorance about the 1979, he wrote:2 and they must be kept up-to-date to effects of health care. He recognised 'It is surely a great criticism of our take account of new evidence. that people who want to make more profession that we have not organised a If this is not done, important effects informed decisions about health care critical summary, by specialty or sub of health care (good and bad) will not specialty, adapted periodically, of all be identified promptly, and people relevant randomised controlled trials.' using health services will be ill served as 1Deputy Director, UK Cochrane Centre, NHS Research & Development Programme, In 1987 Cochrane referred to a sys a result. Without systematic, up-to-date Summertown Pavilion, Middle Way, Oxford tematic review of randomised con reviews of previous research, plans for OX2 7LG, UK trolled trials (RCTs) of care during new research will not be well informed.
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As a result, researchers and funding The methods used in preparing sys context of the Collaboration's eight bodies will miss promising leads, and tematic reviews draw on the work of guiding principles, will ensure that it embark on studies asking questions Cochrane methods working groups. succeeds in getting to grips with the that have already been answered. 5 These organise and disseminate the important agenda bequeathed by work of methodologists who have come Archie Cochrane. The Cochrane Collaboration together to improve the validity and The Cochrane Collaboration devel precision of systematic reviews. Cochrane A L. Effectiveness and Efficiency. oped in response to Cochrane's call for The work of the Cochrane groupings Random Reflections on Health Services. London: Nuffield Provincial Hospitals systematic, up-to-date reviews of all described above is facilitated in a vari Trust, 1972. (Reprinted in 1989 in relevant RCTs of health care. The UK ety of ways by the work of Cochrane association with the BMJ) National Health Service Research and centres. The characteristics of each 2 Cochrane A L.1931-1971: a critical review, Development Programme took up this Cochrane centre reflect the interests of with particular reference to the medical suggestion and provided funds to the individuals associated with it and profession. In: Medicines for the year 2000. London: Office of Health establish a 'Cochrane Centre', to collab the resources made available to them; Economics, 1979,1-11. orate with others to facilitate systematic but all centres share a responsibility for 3 Cochrane A L. Foreword. In: Chalmers I, reviews of randomized controlled trials helping to co-ordinate and support the En kin M, Keirse M J N C (eds). Effective across all areas of health care.6•7 A year Cochrane Collaboration. care in pregnancy and childbirth. Oxford: later, in October 1993, 77 people from Consumers participate throughout Oxford University Press, 1989. 4 Mulrow CD. The medical review article: nine countries founded 'The Cochrane most of the organisation. Collaborative state of the science. Ann tnt Med 1987; Collaboration'. review groups, fields and Cochrane 106: 485-488. The Cochrane Collaboration has centres all seek input and feedback 5 Antman EM, Lau J. Kupelnick B, Mosteller evolved rapidly, but its basic objectives from consumers, which the Cochrane F, Chalmers T C. A comparison of results of and principles have remained the same. Collaboration considers essential in meta-analyses of randomized control trials and recommendations of clinical It is an international organization that order to fulfil its goals. experts. JAMA 1992; 268: 240-248. aims to help people make well 6 Chalmers I, Dickersin K, Chalmers T C. informed decisions about health care The Cochrane Library Getting to grips with Archie Cochrane's by preparing, maintaining and ensur Cochrane reviews and information agenda. BMJ 1992; 305: 786-788. ing the accessibility of systematic about the collaborative review groups, 7 Editorial. Cochrane's Legacy. Lancet 1992; 340: 1131-1132. reviews of the effects of health care together with information about all the 8 Chalmers I, Sackett D, Silagy C. The interventions. The Collaboration 1s other groupings registered as contribu Cochrane Collaboration. In: Maynard A, being built on eight values: tors to the Collaboration are published Chalmers I (eds). Non-random reflections collaboration quarterly in The Cochrane Library. on health services research: on the 25 building on the enthusiasm of Several databases are included in The anniversary ofArchie Cochrane's Effectiveness and Efficiency. London: BMJ individuals Cochrane Library. One of them, The Books,1997: 231-249. avoiding duplication Cochrane Database of Systematic minimising bias Reviews, contains Cochrane reviews keeping up to date and another, The Cochrane Controlled ensuring relevance Trials Register, is a bibliographic data • ensunng access base of controlled trials. The Database continually improving the quality of Abstracts of Reviews of Effectiveness of its work. (DARE) includes structured abstracts How to contact Preparation and maintenance of of systematic reviews which have been Evidence-Based Dentistry Cochrane reviews is the responsibility critically appraised by reviewers at the of international collaborative review NHS Centre for Reviews and Dissemi Written communications should be groups. At mid-1998, the existing nation in York and by other people, e.g. sent to: Evidence-Based Dentistry, review groups (over 40) cover most of from the American College of Physi British Dental Association, 64 Wim the important areas of health care. The cians' Journal Club and the journal Evi pole Street, London W1M SAL, UK members of these groups dence-Based Medicine. The Cochrane researchers, health care professionals, Review Methodology Database is a bib Telephone: 0171-935 0875 consumers, and others - share an liography of articles on the science of Facsimile: 0171-224 0603 interest in generating reliable, up-to research synthesis. date evidence relevant to the preven The Collaboration is still very young To get in touch bye-mail contact: tion, treatment and rehabilitation of but it has already achieved a great deal. 8 [email protected]. uk particular health problems or groups of The continued enthusiasm and good problems. An example is the Cochrane will of individuals, combined with Oral Health Group. strategic alliances developed within the
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