While the term evidence-based medicine (EBM) first appeared around 1990, its origins were in the 1960’s. As recounted by Ariel Zimmerman, in her recent article “Evidence-Based Medicine: A Short History of a Modern Medical Movement,” one of the important driving forces behind the development of what became known as EBM was the institution of the Canadian national health plan (Medicare). McMaster University, founded in 1968 in Hamilton, Ontario, is arguably the birthplace of EBM. It was one of four new schools established in the wake of Canadian health reform, in an effort to integrate concepts of epidemiology and public health into the medical curriculum. It’s not too much of a stretch to assert that a desire to ensure optimal use of finite health care resources – the best outcomes at the lowest cost – led to what eventually became a world-wide effort to promote a more systematic, less variable and idiosyncratic, approach to clinical care. In other words, if you want value, practice evidence-based medicine.
This was a key revelation to me as I read the series of articles on EBM in the most recent issue of Virtual Mentor, the AMA’s on-line ethics journal. We talk about value as the ratio of quality to cost; as a result, we often focus on the numerator and the denominator separately, with a natural inclination among clinicians to place far more value on the quality component than the cost. But the best evidence-based practice automatically maximizes value, for at least a few reasons.
- EBM leads to less variability; specifically, it eliminates variability that does not add value, while preserving acceptable variability due to either lack of evidence or evidence that multiple approaches might lead to the same value. Such consistency will necessarily decrease waste.
- The best evidence (which admittedly is not always available, especially in pediatrics) incorporates some type of cost-benefit analysis. Synthesizing such evidence into care guidelines helps ensure that both the numerator and denominator of the value equation are considered.
- One less-emphasized aspect of EBM is the explicit incorporation of patient preferences into the decision making process. This can be done either in the guideline development stage, by using data about average patients into the analysis, or at the bedside with the use of decision aids. This is really the ultimate way of ensuring that what we do is of most value to those we serve.
None of this is easy. First, the evidence base may be lacking or uncertain. Several of the articles talk about the challenges in communicating issues of risk and benefit, including a delightful essay by the late Stephen Jay Gould. Another article talks about medico-legal aspects of EBM. And there are indications that patients are somewhat skeptical about the whole notion of evidence-based medicine, feeling that all medicine must be evidence-based, and that more care always mean better care. (Both of these assertions, by the way, are demonstrably not true.)
Nevertheless, as we work to improve the value of the care we provide – by decreasing our unnecessary variability – we’ll be best served by following the methods of evidence-based practice. As difficult as it may be, it’s much better than the alternatives.