Evidence-Based Medicine at a Glance
- Evidence-based medicine (EBM) is the use of the best current evidence in making decisions about the care of individual patients.
- EBM is predicated on asking clinical questions, finding the best evidence to answer the questions, critically appraising the evidence, applying the evidence to the treatment of specific patients, and saving the critically appraised evidence.
- The EBM approach is most appropriate for frequently encountered conditions.
- Results from well-designed clinical studies involving intact patients are at the pinnacle of the hierarchy of evidence used to practice EBM.
- Recommendations about treatment, diagnosis, and avoidance of harm should take into account the validity, magnitude of effect, precision, and applicability of the evidence on which they are based.
Until the 1940s there was no gold standard for determining whether a treatment was effective. The publication of the randomized controlled clinical trial (RCT) that demonstrated that streptomycin was effective in the treatment of pulmonary tuberculosis was a landmark event.1 Thereafter, the RCT quickly became the gold standard for determining whether a treatment is effective.
Hundreds of RCT were conducted between 1950s and the 1970s. However, their results were not cataloged or used systematically to inform medical decision-making. In 1972, Archie Cochrane, a British epidemiologist and physician, published his response to being asked to evaluate the effectiveness of the British National Health Service in delivering health care to the population of the United Kingdom. In his analysis, he concluded that medical science was poor at distinguishing interventions that were effective from those that were not and that physicians were not using available evidence from clinical research to inform their decision-making.2 See http://www.cochrane.org/about-us/history/archie-cochrane for more information on Archie Cochrane.
Groups of like-minded epidemiologists and physicians responded to Archie Cochrane's challenge by examining the methods by which medical decisions and conclusions were reached and proposed an alternative approach based on finding, appraising, and using available data from clinical research involving intact patients.3 In 1985, Sackett et al published Clinical Epidemiology: A Basic Science for Clinical Medicine, which detailed the rationale and techniques of this evidence-based approach.3 These authors and others reduced the rules of evidence to a small subset of principles that were easier to teach and understand, and reintroduced the concept in 1992.4 They named this technique evidence-based medicine (EBM). It was defined as the conscientious, explicit, and judicious use of the best current evidence in making decisions about the care of individual patients.4 Whereas making decisions about therapy has been the primary focus of EBM, its principles have been extended to diagnosis, prognosis, avoidance of the harmful effects of interventions, determination of cost-effectiveness, and economic analyses.
The introduction of EBM was met with considerable hostility. It was perceived as cookbook medicine, old hat, too restrictive, and an insult to those already trying to practice good medical care. The definition was softened to include the integration of independent ...