Evidence-based medicine (EBM) is a form of medicine that aims to optimize decision-making by emphasizing the use of evidence from well designed and conducted research. Although all medicine based on science has some degree of empirical support, EBM goes further, classifying evidence by its epistemologic strength and requiring that only the strongest types (coming from meta-analyses, systematic reviews, and randomized controlled trials) can yield strong recommendations; weaker types (such as from case-control studies) can yield only weak recommendations. The term was originally used to describe an approach to teaching the practice of medicine and improving decisions by individual physicians.[1] Use of the term rapidly expanded to include a previously described approach that emphasized the use of evidence in the design of guidelines and policies that apply to populations ("evidence-based practice policies").[2] It has subsequently spread to describe an approach to decision making that is used at virtually every level of health care as well as other fields, yielding the broader term evidence-based practice.[3]

Whether applied to medical education, decisions about individuals, guidelines and policies applied to populations, or administration of health services in general, evidence-based medicine advocates that to the greatest extent possible, decisions and policies should be based on evidence, not just the beliefs of practitioners, experts, or administrators. It thus tries to assure that a clinician's opinion, which may be limited by knowledge gaps or biases, is supplemented with all available knowledge from the scientific literature so that best practice can be determined and applied. It promotes the use of formal, explicit methods to analyze evidence and make it available to decision makers. It promotes programs to teach the methods to medical students, practitioners, and policy makers. The term "evidence-based medicine" was first coined and developed by doctors at McMaster University Medical School in the 1980s.[4] The first Centre for Evidence-Based Medicine was established at the University of Oxford by David Sackett in 1995.

In its broadest form, evidence-based medicine is the application of the scientific method into healthcare decision-making. Medicine has a long tradition of both basic and clinical research that dates back at least to Avicenna.[5][6] However until recently, the process by which research results were incorporated in medical decisions was highly subjective. Called "clinical judgment" and "the art of medicine", the traditional approach to making decisions about individual patients depended on having each individual physician determine what research evidence, if any, to consider, and how to merge that evidence with personal beliefs and other factors. In the case of decisions that applied to populations, the guidelines and policies would usually be developed by committees of experts, but there was no formal process for determining the extent to which research evidence should be considered or how it should be merged with the beliefs of the committee members. There was an implicit assumption that decision makers and policy makers would incorporate evidence in their thinking appropriately, based on their education, experience, and ongoing study of the applicable literature.

Beginning in the late 1960s, several flaws became apparent in the traditional approach to medical decision-making. Alvan Feinstein's publication of Clinical Judgment in 1967 focused attention on the role of clinical reasoning and identified biases that can affect it.[7] In 1972, Archie Cochrane published Effectiveness and Efficiency, which described the lack of controlled trials supporting many practices that had previously been assumed to be effective.[8] In 1973, John Wennberg began to document wide variations in how physicians practiced.[9] Through the 1980s, David M. Eddy described errors in clinical reasoning and gaps in evidence.[10][11][12][13] In the mid 1980s, Alvin Feinstein, David Sackett and others published textbooks on clinical epidemiology, which translated epidemiological methods to physician decision making.[14][15] Toward the end of the 1980s, a group at RAND showed that large proportions of procedures performed by physicians were considered inappropriate even by the standards of their own experts.[16] These areas of research increased awareness of the weaknesses in medical decision making at the level of both individual patients and populations, and paved the way for the introduction of evidence based methods.

The term "evidence-based medicine", as it is currently used, has two main tributaries. Chronologically, the first is the insistence on explicit evaluation of evidence of effectiveness when issuing clinical practice guidelines and other population-level policies. The second is the introduction of epidemiological methods into medical education and individual patient-level decision-making.

The term "evidence-based" was first used by David M. Eddy in the context of population-level policies such as clinical practice guidelines and insurance coverage of new technologies. He first began to use the term "evidence-based" in 1987 in workshops and a manual commissioned by the Council of Medical Specialty Societies to teach formal methods for designing clinical practice guidelines. The manual was widely available in unpublished form in the late 1980s and eventually published by the American College of Medicine.[12][17] Eddy first published the term "evidence-based" in March, 1990 in an article in the Journal of the American Medical Association that laid out the principles of evidence-based guidelines and population-level policies, which Eddy described as "explicitly describing the available evidence that pertains to a policy and tying the policy to evidence. Consciously anchoring a policy, not to current practices or the beliefs of experts, but to experimental evidence. The policy must be consistent with and supported by evidence. The pertinent evidence must be identified, described, and analyzed. The policymakers must determine whether the policy is justified by the evidence. A rationale must be written."[18] He discussed "evidence-based" policies in several other papers published in JAMA in the spring of 1990.[18][19] Those papers were part of a series of 28 published in JAMA between 1990 and 1997 on formal methods for designing population-level guidelines and policies.[20]

The term "evidence-based medicine" was first used slightly later, in the context of medical education. This branch of evidence-based medicine has its roots in clinical epidemiology. In the autumn of 1990, Gordon Guyatt used it in an unpublished description of a program at McMaster University for prospective or new medical students.[21] Guyatt and others first published the term two years later (1992) to describe a new approach to teaching the practice of medicine.[1] In 1996, David Sackett and colleagues clarified the definition of this tributary of evidence-based medicine as "the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. ... [It] means integrating individual clinical expertise with the best available external clinical evidence from systematic research."[22] This branch of evidence-based medicine aims to make individual decision making more structured and objective by better reflecting the evidence from research.[23][24] It requires the application of population-based data to the care of an individual patient,[25] while respecting the fact that practitioners have clinical expertise reflected in effective and efficient diagnosis and thoughtful identification and compassionate use of individual patients' predicaments, rights, and preferences.[22] This tributary of evidence-based medicine had its foundations in clinical epidemiology, a discipline that teaches medical students and physicians how to apply clinical and epidemiological research studies to their practices. The methods were published to a broad physician audience in a series of 25 "Users Guides to the Medical Literature" published in JAMA between 1993 and 2000 by the Evidence based Medicine Working Group at McMaster University. Other definitions for individual level evidence-based medicine have been put forth. For example, in 1995 Rosenberg and Donald defined it as "the process of finding, appraising, and using contemporaneous research findings as the basis for medical decisions."[26] In 2010 by Greenhalgh used a definition that emphasized the use of quantitative methods: "the use of mathematical estimates of the risk of benefit and harm, derived from high-quality research on population samples, to inform clinical decision-making in the diagnosis, investigation or management of individual patients."[27] Many other definitions have been offered for individual level evidence-based medicine, but the one by Sackett and colleagues is the most commonly cited.[22]

The two original definitions highlight important differences in how evidence-based medicine is applied to populations versus individuals. When designing policies such as guidelines that will be applied to large groups of people in settings where there is relatively little opportunity for modification by individual physicians, evidence-based policymaking stresses that there be good evidence documenting that the effectiveness of the test or treatment under consideration.[2] In the setting of individual decision-making there is additional information about the individual patients. Practitioners can be given greater latitude in how they interpret research and combine it with their clinical judgment.[22][28] Recognizing the two branches of EBM, in 2005 Eddy offered an umbrella definition: "Evidence-based medicine is a set of principles and methods intended to ensure that to the greatest extent possible, medical decisions, guidelines, and other types of policies are based on and consistent with good evidence of effectiveness and benefit."[29]

Both branches of evidence-based medicine spread rapidly. On the evidence-based guidelines and policies side, explicit insistence on evidence of effectiveness was introduced by the American Cancer Society in 1980.[30] The U.S. Preventive Services Task Force (USPSTF) began issuing guidelines for preventive interventions based on evidence-based principles in 1984.[31] In 1985, the Blue Cross Blue Shield Association applied strict evidence-based criteria for covering new technologies.[32] Beginning in 1987, specialty societies such as the American College of Physicians, and voluntary health organizations such as the American Heart Association, wrote many evidence-based guidelines. In 1991, Kaiser Permanente, a managed care organization in the US, began an evidence based guidelines program.[33] In 1991, Richard Smith wrote an editorial in the British Medical Journal and introduced the ideas of evidence-based policies in the UK.[34] In 1993, the Cochrane Collaboration created a network of 13 countries to produce of systematic reviews and guidelines.[35] In 1997, the US Agency for Healthcare Research and Quality (then known as the Agency for Health Care Policy and Research, or AHCPR) established Evidence-based Practice Centers (EPCs) to produce evidence reports and technology assessments to support the development of guidelines.[36] In the same year, a National Guideline Clearinghouse that followed the principles of evidence based policies was created by AHRQ, the AMA, and the American Association of Health Plans (now America's Health Insurance Plans).[37] In 1999, the National Institute for Clinical Excellence (NICE) was created in the UK.[38]

On the medical education side, programs to teach evidence-based medicine have been created in medical schools in Canada, the US, the UK, Australia, and other countries. A 2009 study of UK programs found the more than half of UK medical schools offered some training in evidence-based medicine, although there was considerable variation in the methods and content, and EBM teaching was restricted by lack of curriculum time, trained tutors and teaching materials.[39] Many programs have been developed to help individual physicians gain better access to evidence. For example, Up-to-date was created in the early 1990s.[40] The Cochrane Center began publishing evidence reviews in 1993.[33] BMJ Publishing Group launched a 6-monthly periodical in 1995 called Clinical Evidence that provided brief summaries of the current state of evidence about important clinical questions for clinicians.[41] Since then many other programs have been developed to make evidence more accessible to practitioners.

Continue reading here:

Evidence-based medicine - Wikipedia, the free encyclopedia