Evidence-based medicine and the Cochrane Collaboration in anaesthesia.

In 1972, the British epidemiologist Archie Cochrane book, Evidence-Based Medicine: How to Practice and Teach Evidence-Based Medicine.3 The following is a short published his view of the principles on which the delivery outline of the five principles of EBM. of health care should be based.1 Put simply, he stated that limited resources should be used equitably to provide care of proven benefit. Cochrane promoted randomized Ask a clinical question you can answer controlled trials (RCT) as the most reliable source of In order to find an answer to your clinical question, the evidence on which to base decisions about the effectivequestion will have to be clear and well focused. For ness of health care interventions. He advocated the example, see the following. compilation of a comprehensive catalogue of definitive reviews of scientifically valid clinical trials for each special(i) Who is the question about? How could you describe ity. These regularly updated reviews could be consulted to a group of patients similar to this particular patient? assist with clinical decision-making. Medical interventions (E.g. a healthy teenager, an overweight pregnant would thus be scientifically based on properly planned and woman or an elderly person with coronary heart executed clinical trials (distilled where possible into equally disease.) scientifically valid reviews) rather than on anecdote, habit, (ii) Which treatment or manoeuvre are you considering selective experience, faulty memory, or a skewed sample for the patient? (E.g. type of anaesthesia, route for of the relevant clinical trials. The impact of Cochrane’s central venous catheterization or antibiotic in the book,1 Effectiveness and Efficiency, was not fully recognized intensive care unit.) at the time, but it captured the essence of today’s evidence(iii) What is the desired (or undesired) outcome for the based medicine movement. Cochrane’s vision of a reliable, patient? (Reduced postoperative nausea and vomiting, comprehensive and accurate medical database, the Cochrane reduced morbidity or mortality, reduced costs.) Library, is approaching reality. A good question will cover these three areas of subject, intervention and outcome, each of equal importance. Failure to frame the question properly will make it harder to find Evidence-based medicine useful and applicable answers. For example, ‘Is propofol a The Cochrane Collaboration is a major focus of activity better induction agent than thiopental? ’ contrasted with and a rich source of information within the evidence-based ‘Does propofol lead to fewer unexpected overnight admismedicine movement. The term evidence-based medicine sions than thiopental after adult day case laparoscopic (EBM) originated at McMaster University in Canada, and sterilization? ’ has been defined as ‘the conscientious, explicit and judicious use of the best evidence in making decisions about the care Search for evidence of individual patients.2–4 Thus to practice EBM is to integrate clinical expertize with the best available external Information technology has undoubtedly made it easier to evidence from systematic research.3 search the medical literature, and most institutions provide computers that allow electronic searching. Several databases The practice of EBM is described in David Sackett’s