Evidence-based medicine (EBM) is the integration of best research evidence with clinical expertise and patient values ... When these three elements are integrated, clinicians and patients form a diagnostic and therapeutic alliance which optimizes clinical outcomes and quality of life. Centre for Evidence Based Medicine
While this quote focuses on medicine, it also captures four key elements relevant to all professions and professionals.
The first element is research evidence, essentially what works and why.
The second element is professional expertise, our capacity to understand and apply our professional knowledge in the circumstances of the particular case.
The third element is the patient or client, each with their specific attitudes and needs.
The final element is the integration of the first three elements - the diagnostic and therapeutic alliance - to provide the solution that best meets client needs.
In my brief introductory post on the case of evidence base medicine, I suggested that my instinctive first reaction on hearing about evidence based medicine was to say that's odd, I thought that all medicine was evidence based. I also suggested that this has proved, in fact, to be far from true.
Before continuing my analysis I should note that the Australian Broadcasting Corporation's Radio National has just completed a rather good two part series - Facing the Evidence - on evidence based medicine. The first part is already available in transcript and pod cast. The second will be available shortly.
Returning to my theme, when you look as I did in my last post at the standard way all professionals are trained, you can see that that training focuses on the transfer of existing knowledge and skills to the new professional, knowledge and skills that that professional then applies. The professional then builds on this base through practice, at the same time using various professional development activities to try to keep in touch with new developments.
But what happens if that existing knowledge base is in fact wrong? How might this arise? To quote from the first part of the ABC program:
Every day doctors and other health professionals use treatments that are harmful, or fail to use therapies that have been proven to work. In the US there is so much medical error that Congress has directed the Institute of Medicine to develop a strategy to improve the quality of care. In its initial report the Institute noted perhaps as many as 100,000 Americans die every year from medical errors, including the use of inappropriate treatments. That's much more than from car accidents, breast cancer or AIDS. Many more suffer side effects and unnecessary costs
How could this happen?
Part of the problem here lies simply in the placebo effect, that fact that patients respond just to the fact of treatment. So the treatment appears to work, thus supporting the original judgment.
Part of the problem also lies in the fact that individual outcomes can be affected by so many variables and over a considerable time horizon so that the fact of adverse outcomes may not be clear in an individual case or, if clear, may be due to a whole variety of factors external to the treatment itself. There is a linked issue here that relates to the size of the population.
Given that individual outcomes vary greatly, the fact that there is a problem and its scale and scope may only become clear if you look at a population as a whole. That is, the individual professional may have no easy way of detecting the problem in his/her individual cases.
A further problem lies in the nature of the models used.
All professions use models to try to explain a complex world. In economics, for example, models are a common method used to analyse economic behaviour and to suggest possible responses at firm and public policy levels. In the case of medicine, biological models are common.
The problem with all models is that they involve selection of key variables and the specification of relations between those variables. Get either wrong, and outcomes may be very different from those projected by the model.
Doctors have always been concerned about adverse or unexpected outcomes.
In 1972 Professor Archie Cochrane, a Scottish epidemiologist published Effectiveness and Efficiency: Random Reflections on Health Services. This plus Cochrane's subsequent advocacy caused increasing acceptance of the concepts behind evidence-based practice. Cochrane's work was honoured through the naming of centres of evidence-based medical research — Cochrane Centres — and an international organisation, the Cochrane Collaboration.
The explicit methodologies used to determine "best evidence" were then largely established by the McMaster University research group led by David Sackett and Gordon Guyatt. According to the Wikipedia article on evidence based medicine, the term "evidence-based medicine" itself first appeared in the medical literature in 1992 in a paper by Guyatt et al. (Guyatt G, Cairns J, Churchill D, et al. [‘Evidence-Based Medicine Working Group’] "Evidence-based medicine. A new approach to teaching the practice of medicine." JAMA 1992;268:2420-5. PMID 1404801)
From this point, the spread of the concept and its subsequent inclusion in professional training was rapid.
As with any other approach, evidence based medicine has its own methodological problems. However, it also has important lessons for other fields of professional practice.
Previous Posts in the "Towards a Discipline of Practice" Series
- 21 September 2006 Towards a Discipline of Practice
- 22 September 2006 Role of the diagnostic in professional practice - medicine vs law
- 8 January 2007 Reflections on Professional Practice and Practices
- 16 January 2007 Towards a Discipline of Practice - Evidence Based Medicine 1
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