By William H Cordell, MD and Carey D Chisholm, MD

Evidence-Based Medicine or “EBM” is the integration of evidence, experience, and values into clinical decision-making. Evidence-Based Medicine conceptualizes clinical decision-making and practice as the intersection of three circles (evidence, experience, and values). Practicing by any of the three “intersecting circles” alone is bad medicine. For example, practicing by experience alone (Experience-Based Medicine) is practicing by habit or “flying by the seat of one’s pants.” This affords little opportunity for growth as a physician and makes it difficult to incorporate new knowledge into clinical practice. Practicing by values alone (“Emotional-Based Medicine”) is clearly not recommended. Furthermore, practicing by evidence alone is fraught with problems. Many of the patients we care for each day have problems that have not yet been “answered” by “hard science.” It’s the integration of all three “circles” that is Evidence-Based Medicine’s single most important gift to clinical practice and education.   Why have so many clinicians and educators embraced Evidence-Based Medicine?  EBM is one model for thinking about, continually learning, teaching, and practicing Medicine. EBM is in large part a philosophy and skill set that articulates the clinical decision-making process.  EBM is also about translation–the translation of research findings into clinical practice. Importantly, research findings are also translated into terms understandable by patients so they may be informed partners in the decision-making process. For example, what does clinical evidence, derived from studies of large numbers of patients usually in a different locale mean to the single patient now being cared for by me in my practice setting? EBM is very patient-focused and expressly includes the patient in the clinical decision-making process.

The application of EBM skills begins and ends with a single patient and includes the following steps:

1. Formulating answerable questions
2. Rapidly searching for best evidence to answer these questions
3. Critically appraising the evidence for validity and applicability
4. Integrating this appraisal with clinical expertise and patients’ values and applying it back to the individual patient.

It seems, however, that EBM has struck a raw nerve. Critics claim that Evidence-Based Medicine denigrates or ignores clinician experience and the “art of medicine” while promoting “cookbook medicine.” Critics argue that EBM is used as a cost-cutting tool, is an “ivory tower” concept, and will lead to therapeutic nihilism in the absence of evidence from randomized- controlled trials.   

But it seems a lot of bile is being spilled over what many critics incorrectly believe or perceive “evidence-based medicine” to be. We believe this confusion originates from the term “evidence-based” being indiscriminately used as a medical “buzz word de jour”–“evidence- based guidelines,” “evidence-based clinical pathways,” “evidence-based approach,” “evidence- based practice,” and “evidence-based [insert name of any medical specialty here].” Before Evidence-Based Medicine (EBM) can be fairly criticized, we should at least be clear about what EBM is.

The most common misconception about EBM is that it is making decisions based on research evidence alone. In fact, quite the opposite is true. As mentioned earlier, Sackett and his colleagues define Evidence-Based Medicine as “the integration of best research evidence with clinical expertise and patient values.”¹ By clinical expertise we mean the ability to use our clinical skills and past experience in caring for patients. Jadad and Cepeda noted that human beings have over thousands of years developed powerful but nonscientific ways of knowing.² These “hard wired” primal knowledge tools include anecdotes, rules of thumb, tacit knowledge, “sixth sense,” pattern recognition, and “hairs standing up on the back of the clinician’s neck.” Instead of demeaning clinical experience, Evidence-Based Medicine expressly embraces and even celebrates its role in clinical decision-making. EBM is not an exercise for academicians, statisticians, or researchers.  It is not about learning to do research. It is about learning to use research in clinical practice.  EBM teaches clinicians to become informed consumers of the medical literature. As Straus and McAlister³ noted, surveys and audits of front-line clinicians clearly refute the “pseudo-limitation” that EBM is an ivory-tower concept. EBM also deplores dogma, experts, and medical divas.  Because EBM insists that individual clinicians can and should learn to make up their own minds, it is fundamentally about “critical thinking,” a concept threatening to many. EBM teaches clinicians to be skeptical (“show me convincing evidence”), but not cynical (the a priori rejection of evidence). There are many other myths about EBM. To address but a few, EBM is not a better way of reading a journal, “trashing” an article, or running a journal club. EBM does not insist that practice be guided by only meta-analysis or large randomized controlled trials. And EBM is not synonymous with guidelines or clinical pathways.   

But learning EBM does come with a price. Clinicians and learners do need to acquire certain skills (e.g., computer skills, rapid searching, and analysis of evidence), learn new concepts (e.g., hierarchy of evidence, probability revision), and understand the basics of meta- analysis and clinical trials (e.g., randomization, intention-to-treat, baseline comparisons). EBM cannot be mastered by reading a few articles, attending a workshop, or discussing it once a month in a journal club. The principles and skills of EBM must be incorporated into daily practice and become part of the clinician’s mindset toward patient care and continual learning.   

In summary, Evidence-Based Medicine is a philosophy and skill set for integrating evidence, clinical experience, and patient’s preferences, values, and rights. EBM has been one of the most significant paradigm shifts and conceptual advances in facilitating the incorporation of medical innovation into practice. EBM has transformed our thinking about how clinicians should be educated and continue to learn for the rest of their lives.   

Just don’t be fooled if you see the phrase “evidence-based medicine” tagged on to an article title. If it’s not the integration of evidence, experience, and values into clinical decision- making, it’s not Evidence-Based Medicine. It’s not the real thing!

References

1. Sackett DL, Straus SE, Richardson WS, Rosenberg W, Haynes RB. Evidence-based Medicine: How to Practice and Teach EBM. Second ed. New York: Churchill Livingstone; 2000.
2. Jadad AR, Cepeda MS. Evidence-based emergency medicine. Ten challenges at the intersection of clinical research, evidence-based medicine, and pain relief. Ann Emerg Med 2000;36:247-52.
3. Straus SE, McAlister FA. Evidence-based medicine: a commentary on common criticisms. CMAJ 2000;163:837-41.