Evidence based medicine

A new journal to help doctors identify the information they need

Busy doctors have never had time to read all the journals in their disciplines. There are, for example, about 20 clinical journals in adult internal medicine that report studies of direct importance to clinical practice, and in 1992 these journals included over 6000 articles with abstracts: to keep up the dedicated doctor would need to read about 17 articles a day every day of the year.1 In earlier eras limitations in our understanding of human biology and the absence of powerful clinical research methods meant that major advances were published far less commonly than now. Consequently, clinicians' failure to keep up did not harm patients.

Not any more. Rapid advances in physics, chemistry, and molecular biology since the second world war have led to a huge increase in the possibilities for managing patients. Effective treatments have appeared often for the first time. In parallel with these scientific advances researchers have developed methods of applied research—epitomised by the randomised controlled trial—to identify which new ideas for diagnosis, treatment, and predicting outcome actually work. Many do not and may do more harm than good.

Doctors need to know about the studies that show whether new ideas work, but their volume has grown enormously. What's more, many are published in inaccessible places, are not published at all, or are seriously flawed. Most busy doctors lack the time or skill to track down and evaluate this evidence. Although the skills of searching for evidence and critically appraising it are being mastered by growing numbers of doctors, many cannot keep up. Consequently there is a widening chasm between what we ought to do and what we actually do.

Evidence based medicine2 3—which is described at length by William Rosenberg and Anna Donald on p 11224—attempts to fill the chasm by helping doctors find the information that will ensure they can provide optimum management for their patients. In essence, evidence based medicine is rooted in five linked ideas: firstly, clinical decisions should be based on the best available scientific evidence; secondly, the clinical problem—rather than habits or protocols—should determine the type of evidence to be sought; thirdly, identifying the best evidence means using epidemiological and biostatistical ways of thinking; fourthly, conclusions derived from identifying and critically appraising evidence are useful only if put into action in managing patients or making health care decisions; and, finally, performance should be constantly evaluated. The practice of evidence based medicine seems to be able to halt the progressive deterioration in clinical performance that is otherwise routine5 and which continuing medical education cannot stop.6

In 1991 the American College of Physicians began a journal, ACP Journal Club, which aimed to provide doctors with the up to date information they need.7 The editorial team screens far more journals than the average doctor can ever hope to read and identifies research articles of potential clinical relevance. Next, the team scrutinises the research methods used in these studies and rejects those whose conclusions are likely to be invalid or inapplicable.

The selected articles are then described on one page, beginning with an abstract that is structured and rewritten—because many abstracts published in the original journals do not include essential information.8 Each abstract is accompanied by a commentary from an expert in the subject who integrates it with other evidence and draws out the messages for practice. The articles cover the prevention, cause, and course of disease; screening; diagnosis; treatment; and rehabilitation; there are also studies of the economic aspects and quality of care and of strategies for improving the education and performance of doctors.

The results of this process are dramatic and cheering. The 6000 original articles on internal medicine published each year in general journals are distilled to 300, and each article is on one page rather than four or five. Thus, even a doctor with a broadly based clinical practice can keep up with the latest important advances in clinical research by reading a page a day, and still have days to spare.

Not surprisingly ACP Journal Club has a high readership and is found extremely useful by its readers. Now the American College of Physicians and the BMJ Publishing Group are to collaborate to publish Evidence Based Medicine, a development of ACP Journal Club. This will include some abstracts and commentaries published in ACP Journal Club but will also include new ones. These will come from the subspecialties of general medicine and from general practice, paediatrics, surgery, obstetrics and gynaecology, psychiatry, public health, and the parts of anaesthetics—for instance, the management of pain—that are common to much of medicine. Preference will be given to studies that cover conditions—like diabetes and depression—that are common and encountered in all specialties. Evidence Based Medicine will also publish systematic reviews of the effects of health care from the Cochrane Collaboration, selected reports from the York Centre for Reviews and Dissemination, educational material describing how to practise evidence based medicine, and editorials of general interest. Full information on subscribing to the new journal, which will be launched in October 1995, is available in the advertisement in this week's BMJ.*

ACP Journal Club and Evidence Based Medicine will publish the gold that intellectually intense processes will mine from the ore of about 100 of the world's top journals. Doctors owe it to themselves and their patients to make sure that they keep up with what is new and important.