Clinical decision making

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.[citation needed]

Evidence-based guidelines and policies

The term "evidence-based" was first used by David M. Eddy in the course of his work on 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 The manual was widely available in unpublished form in the late 1980s and eventually published by the American College of Medicine.[17][18] Eddy first published the term "evidence-based" in March, 1990 in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."[19] He discussed "evidence-based" policies in several other papers published in JAMA in the spring of 1990.[19][20] 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.[21]

Medical education

The term "evidence-based medicine" was introduced 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.[22] 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."[23] This branch of evidence-based medicine aims to make individual decision making more structured and objective by better reflecting the evidence from research.[24][25] Population-based data are applied to the care of an individual patient,[26] 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.[23]

This tributary of evidence-based medicine had its foundations in clinical epidemiology, a discipline that teaches health care workers how to apply clinical and epidemiological research studies to their practices. Between 1993 and 2000, the Evidence-based Medicine Working Group at McMaster University published the methods to a broad physician audience in a series of 25 "Users’ Guides to the Medical Literature" in JAMA. In 1995 Rosenberg and Donald defined individual level evidence-based medicine as "the process of finding, appraising, and using contemporaneous research findings as the basis for medical decisions."[27] In 2010, Greenhalgh used a definition that emphasized 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."[28] Many other definitions have been offered for individual level evidence-based medicine, but the one by Sackett and colleagues is the most commonly cited.[23]

The two original definitions[which?] highlight important differences in how evidence-based medicine is applied to populations versus individuals. When designing guidelines 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 should be good evidence to document a test´s or treatment´s effectiveness.[29] In the setting of individual decision-making, practitioners can be given greater latitude in how they interpret research and combine it with their clinical judgment.[23][30] in 2005 Eddy offered an umbrella definition for the two branches of EBM: "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."[31]