Evidence-based medicine - history

The 'Wedge' of Best Evidence - Start at the top

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Introduction

See also Evidence-based health care, Evidence-based practice workshops & History of evidence-based approaches in medicine

The notion of using evidence-driven medical research as the basis for clinical practice is attributed to the work of British epidemiologist Archie Cochrane in the 1970s. By analyzing patient outcomes at hospitals in the United Kingdom, Cochrane noticed that much of clinical practice at the time was based on tradition not on empirical evidence. Cochrane discovered that patients whose care was supported by evidence received higher quality care and had better outcomes than patients who did not. In addition, evidence-based medicine improved the overall cost efficiencies at the hospital. Cochrane’s work had a profound impact on the healthcare community, which generated a now widely-accepted shift towards evidence-based health care.

Evidence-based movement of the 20th century

Although the evaluation of procedures and interventions has existed for centuries, it was not until the Scottish epidemiologist, Archie Cochrane, promulgated EBM principles through his 1972 book Effectiveness and efficiency: random reflections on health services. His subsequent efforts at advocacy of empirical methods caused increased acceptance of using the research to make clinical decisions. Today, Cochrane's work is honoured through the international Cochrane Collaboration and the Cochrane Library. Explicit methodologies are used in all of the Cochrane initiatives in order to determine "best evidence" which were established by prominent figures at McMaster such as David Sackett and Gordon Guyatt.

The term "evidence-based medicine" can be traced back to a 1992 paper by Gordon Guyatt and others. In the 1990s, evidence-based medicine emerged as one of the premier research methods in evaluating clinical interventions. What made evidence-based health care different was that it combined the best medical evidence with the values of patients. The available medical literature that applied to patients made it possible to diagnose their problems and to choose treatments that were quantitatively evaluated. By using these methods in large groups of patients with the same illness, doctors were able to develop clinical practice guidelines for the evaluation and treatment of human diseases and conditions. Clinical practice guidelines have been used to aid physicians in the evaluation of their performance and identifying new areas for study.

Systematic reviews of the medical literature, large randomized controlled trials (the best way to assess efficacy of treatments), and large prospective studies (followed up over time) are three potentially important types of medical research as they are seen to be high up on the evidence-based pyramid of evidence about tests and treatments. Reports of the experiences of individual patients or small groups provide less reliable evidence, although they too can provide insight into the many possible adverse effects of treatments.