Key points

Overview

While counseling his students more than 2500 years ago, Hippocrates declared that the physician need to “rely on actual evidence rather than on conclusions resulting solely from reasoning, because arguments in the form of idle words are erroneous and can be easily refuted.” Since the early days of medicine, there has been a need for evidence-based inquiries that enable a physician to ascertain and apply the best treatment strategy for each patient. Even during the early era of medicine, physicians understood the importance of using evidence to guide treatment protocols. Although we identify the outcomes movement and evidence-based medicine as new terms, the ideas that embody these themes are as old as organized medicine itself. Increased government involvement combined with an exceedingly demanding patient population have made the modern outcomes movement and evidence-based medicine an essential component of research and clinical practice.

Overview

While counseling his students more than 2500 years ago, Hippocrates declared that the physician need to “rely on actual evidence rather than on conclusions resulting solely from reasoning, because arguments in the form of idle words are erroneous and can be easily refuted.” Since the early days of medicine, there has been a need for evidence-based inquiries that enable a physician to ascertain and apply the best treatment strategy for each patient. Even during the early era of medicine, physicians understood the importance of using evidence to guide treatment protocols. Although we identify the outcomes movement and evidence-based medicine as new terms, the ideas that embody these themes are as old as organized medicine itself. Increased government involvement combined with an exceedingly demanding patient population have made the modern outcomes movement and evidence-based medicine an essential component of research and clinical practice.

Early evidence-based medicine movement

The outcomes movement and evidence-based medicine were spurred on by many early proponents, some of whom were shunned by their peers in response to the radical new ideas that they imposed. During the 1800s, the celebrated nurse Florence Nightingale used evidence gained from careful record keeping, observation, and statistical measurements to foster health care reform, becoming one of the earliest supporters of evidence-based medicine. Ernest Codman advocated meticulous data collection, patient follow-up, and the analysis and interpretation of patient outcomes to improve care and treatment methods. Although his ideas had practical value, his peers did not share his enthusiasm for the improvement of outcomes, instead preferring to alienate the brilliant surgeon and continue using the dated techniques and treatment methods they had learned during their medical training. Archie Cochrane championed the use of rigorously performed randomized controlled trials (RCTs) and systematic reviews, sparking the interest of those who would go on to place them at the top of the research hierarchy. Although they did not articulate these efforts in a particular terminology, these early pioneers were instrumental in the implementation of outcomes research and evidence-based methodology in medicine.

Modern evidence-based medicine movement

The modern outcomes movement in the United States has its roots in the Era of Expansion of the 1950s and 1960s, which stimulated a massive overhaul of the medical industry. This period was distinguished by a substantial increase in the number of medical facilities and physicians, extraordinary advances in science and medical technology, and for the first time an augmentation of medical insurance coverage into the majority of United States households. These changes created a different hospital system, attracting private investors who were looking to increase profit margins. The increased demand for medical services coupled with the high expenses incurred from sophisticated medical technology led to a substantial increase in medical costs. The soaring cost of medical care caused a crisis whereby patients began to demand lower prices for medical services. Also feeling the burden of high costs, the federal government and employers followed suit and started dictating the costs of health care, paying the hospitals much less than they were charging for the services that were being provided.

At the same time, the American public began to question the quality of the new, high-tech, and expensive treatment protocols that were quickly becoming standard practice. The Era of Expansion initially generated a belief that by increasing hospital admittance rates the overall population would be healthier, a belief that was later found invalid. Several investigators documented the variations in health care among different regions and hospitals, and soon established that high admittance rates and medical costs do not always translate to better medical care and a healthier population. These studies also raised concerns over the impact these substantial variations in health care might have on a population. Areas with easy access to health care and high admittance rates may have increased rates of unnecessary procedures, resulting in higher rates of preventable complications and increased medical costs. Populations in areas with low admittance rates may experience difficulty obtaining access to care and may not benefit from the advances of modern medicine. Because of the high variability of medical and surgical services among practitioners, hospitals, and regions, the optimal rate of hospital admittance and surgical interventions for different patients and conditions remains to be determined. This research avenue demands continued exploration so that costs can be contained and health care among all populations simultaneously improved.

Momentum of evidence-based strategies in the medical community

Although the outcomes movement has gathered considerable momentum in the medical research sector, its application has not halted the continued escalation of health care costs and the uncertain quality of medical services. Even so, the outcomes movement has played an important role in paving the way for the widespread implementation and acceptance of evidence-based strategies into the medical community. In fact, evidence-based medicine was specifically designed to address the shortcomings that are apparent in the outcomes movement by focusing simply on the application of outcomes data rather than on the scientific rigor of deriving these outcomes data. Physicians David Sackett and Gordon Guyatt would lay the initial groundwork for the development of evidence-based medicine, and both would go on to provide substantial contributions to the continued evolution of the concept.

While studying ways to improve treatment compliance of hypertension in 1975, Sackett discovered a disturbing trend. He and the other investigators found that a determining factor in the prescribing treatment for hypertension was the graduating year of the physician. It appeared that the treating physicians were basing their management of patients on the treatment protocol that was considered acceptable at the time they had completed their medical training, even if the treatment was completely outdated. This recurring theme prompted David Sackett, Brian Haynes, Peter Tugwell, and Victor Neufeld to publish a series of articles beginning in 1981 in the Canadian Medical Association Journal highlighting the importance of a physician’s ability to carefully read and comprehend research published in medical journals. In this series of articles, the investigators emphasize using epidemiology concepts to apply the best available evidence and solve clinical problems. These articles were aimed at helping the busy clinician stay up to date with the latest advances in medicine.

The phrase “evidence-based medicine” was initially coined in 1990 by Gordon Guyatt, after an unsuccessful attempt to implement a new strategy he originally defined “Scientific Medicine” into an internal medicine residency program at McMasters University. His Scientific Medicine program was designed to enhance clinical treatment with the application of current systematic scientific evidence, modeled after the ideas of his mentor David Sackett. The program was promptly disparaged by his peers, who were offended at the implication that current decision-making practices in medicine lacked scientific qualities. This reaction persuaded Guyatt to give his initiative a new designation: evidence-based medicine. With this new name his proposed residency program curriculum was well received, compelling Guyatt to officially publish the term in a 1991 editorial. Not long after, a team at McMasters University, including Sackett and Guyatt, continued improving on the idea of evidence-based medicine, eventually leading to an international collaboration between Canadian and American academicians to further enhance this novel approach.

International Evidence-Based Medicine Working Group

The International Evidence-Based Medicine Working Group, as it became known, worked to further refine evidence-based medicine from Sackett’s original critical appraisal articles and Guyatt’s previous concepts. The Group discovered that although the critical appraisal articles were helpful in guiding clinicians to better understand the quality of evidence in scientific articles, they lacked instruction on applying the evidence gained from scientific studies to the clinical setting. After addressing potential problems and enhancing the existing components of evidence-based medicine, an improved version was officially introduced in 1992, promoting the critical appraisal, identification, and application of scientific evidence. This article was followed by the JAMA User’s Guide to the Medical Literature , a publication initially designed to help physicians better understand the basic concepts of evidence-based medicine, later progressing to a series of 25 articles as the initiative evolved and gained acceptance.

Evidence-based medicine bridges the gap between research and practice

At its core, evidence-based medicine attempts to bridge the gap between the realms of research and practice. Although seemingly simple, this ideal is exceedingly complicated, plagued by countless arguments concerning effectiveness, a lack of procedural and technical comprehension, a pervasive fear of abuse, and an overabundance of poorly performed studies that hamper the use and quality of data. To account for these challenges and address the opposition to evidence-based medicine, Sackett and colleagues published a short explanation titled “Evidence based medicine: what it is and what it isn’t,” which highlights the implications and importance of such a system. These investigators also explain that a good clinician must rely on individual experience and expertise, and incorporate the best available evidence to achieve the best possible outcomes, but that neither of these elements is sufficient in and of itself to provide the best care. Clinical experience is vital, but can quickly become outdated without the support of a good scientific knowledge base, whereas evidence alone can result in the poor management of a patient when the data are not applied appropriately, based on specific patient characteristics and needs. Thus, it is essential that physicians use both clinical experience and the best available evidence to provide the best treatment, a concept that has now been established as a fundamental principle for evidence-based practices.