Thursday, July 24, 2014
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What’s Wrong with Evidence-Based Medicine?

SEATTLE – Every health-care system balances coverage, quality, and cost – often focusing on one or two at the expense of the others. European systems, for example, tend to focus on coverage and ensure universal access to care; in the United States, by contrast, quality appears to be paramount.

But, whatever one’s view is about the proper priorities, it is clear that the US has room for improvement in all three areas. Fortunately, efforts are underway to address each of them. And efforts in the US have implications for other countries as well.

The US Patient Protection and Affordable Care Act (the landmark legislation now widely known as “Obamacare”) aims to widen coverage, while so-called accountable care organizations, such as Kaiser Permanente, try to contain costs by aligning the interests of providers and payers. However, efforts to raise quality through the application of evidence-based medicine (EBM) risk ignoring what we know about human cognition and expertise, and may undermine the vital role played by a physician’s expert judgment.

There are at least three reasons to be wary. For starters, EBM is grounded in a fundamental distrust of physicians’ intuition – that is, the rendering of pattern-based judgments that rely on years of experience. To be sure, there are good reasons to be skeptical of intuition, given the countless cases in which it has proved to be wrong. But it does not follow that all cases of intuition are flawed or that skilled intuition has no function in healthcare.

Physicians develop expertise over many years, and when they have ample opportunities for feedback about their judgments, their intuitions are valuable, particularly in more complex cases. An experienced physician will evaluate a patient’s vital signs and test results in the context of the patient’s life – for example, whether he is an octogenarian with diabetes and a smoker’s cough, or a three-week premature baby. With heuristics, intuition, and experience, an experienced physician can best understand a complicated case and develop a plan.

In fact, an experienced doctor’s conclusions may be more accurate than those provided by EBM. That is because EBM, though based on data from randomized trials and rigorous experiments, is designed for situations that approximate the conditions of patients in those tests. The problem is that when the context changes, the trial results become less reliable.

In such cases, the physician must determine how close his or her patient’s situation matches that in the relevant studies. If the disease is not as advanced as in the trials, the doctor will have to decide whether to embark on the recommended protocol. And clinicians may be unsure about which constraints are inviolate. Ultimately, the final judgment is informed by personal experience and pattern recognition, an approach that EBM supporters discount or even disparage.

A second problem with EBM is that it offers little guidance when a medical condition is evolving. For example, acute asthma may be the focus of care at one moment, but might shift to the patient’s diabetes later. EBM guidelines focus on asthma treatment or diabetes, but not both, or even how they may interact and change over time.

Finally, and perhaps most critically, one must ask how clinicians are to make decisions when there are gaps in the EBM knowledge base. Doctors often spot trends and develop hypotheses that involve guesswork, and that are validated by trials only later. Should doctors therefore ignore observed patterns until the data are in? Indeed, one might wonder how such trials are initiated at all if clinicians do not tentatively explore a problem in the first place. To insist that all treatment decisions be based on existing best practices stifles this exploration and prevents potential medical breakthroughs.

Advocates of EBM respond that it is the job of researchers to generate the data that are turned into best practices; the clinician’s role is to implement the results. But this approach runs counter to medical history, in which advances come only after practitioners notice anomalies, discover flaws in current “best practices,” or improve on existing approaches. Many medical advances, from ulcer therapies to joint replacement, have evolved through clinician curiosity, not as a result of trials.

Moreover, important sources of EBM have themselves proved to be misleading. The Framingham Heart Study, considered the gold standard in its field, was shown to be flawed, owing to its focus on white males. For example, a key symptom of a heart attack identified by the study (the feeling of “an elephant sitting on my chest”) is found in only 5% of women. As one emergency medicine physician ruefully admitted to us, “I think about all the women I sent home to their deaths because I was following best practices.”

As we consider a likely future in which physicians adhering to EBM are paid more, we must consider the cognitive limitations and the human cost of unquestioning compliance with so-called “best practices.” A more effective approach must be to combine EBM with the expertise and intuition of experienced caregivers, and to take the benefits of both.

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  1. CommentedAndrew Min

    Physicians' intuition is incredibly problematic because clinicians are bad at correctly detecting and leveraging past trends. See, e.g., Gawande, A. 1999. When doctors make mistakes. The New Yorker. and Dawes, R. M., Faust, D., & Meehl, P. E. 1989. Clinical versus actuarial judgment. Science, 243, 1668-1674. Evidence-based medicine is certainly imperfect, but I'm not sure how one could make a causal claim that intuition is superior.

  2. CommentedAndrej Grajn

    All the elaborate responses of previous commentators hold merit. Those of us who practice medicine know fairly well that our art cannot be simply described in algorithms and guidelines which are far to primitive to encompass the complex nature of the pathology.

  3. CommentedEdward Ponderer

    Medicine is a lot more nonlinear and synergistic than physics, and even physics has discovered quantum entanglement in the sub-classical world, and deterministic chaos dominating the generally Newtonian everyday world. Non-linearity is the key, and while linear incremental steps as in the perturbations methods of physics may be appropriate, they must be shallow steps, work there way in, and be prepared not only to back step--but for effects that don't simply reverse.

    If one may generalize too, the physician as well-described by Ms. Klein, is as a neural net that has been exposed to many training sessions over the years which provides complex pattern recognition--a basis function in a complex space that will not come out in one-dimension ECM, even if its statistical data base is much larger.

    Simply put though, we are not in a mutually responsible society, but one where ego is king. When the decision makers are not the recipients of the programs that they manage, one can be sure that the best interests of those who will use the program are uppermost on these decision makers minds.

    Years back there was the famous scandal when it was uncovered from internal memos that the International Red Cross had avoided using new HIV detection technology to test blood donations because it was determined that projected legal fees and risks of financial loss in lost wrongful death suits were less than the costs of implementing the tests.

    Hopefully not quite as callous--hopefully, but nonetheless, do the EBM proponents also not know where their bread is buttered?

  4. CommentedZsolt Hermann

    Maybe we can answer the question in the title with another question:
    "Whose evidence?"

    Evidence would mean some absolute fact, data we simply do not have.
    Through the latest advances of psychology, or quantum physics we now start to understand that our perception of reality is completely subjective.

    This is why we find in well respected scientific publications, peer review journals two completely opposing ideas, theories, practices proven despite the highest statistical scrutiny.

    Every observer is biased to such an extent that even so called "double blind" studies will yield results that are mostly favourable for those leading the research, trying to prove themselves right.

    And on top of this in medicine basically everything from drugs to implants is industry driven, where physicians, managers are completely at the mercy of marketing, financial support, open or hidden bribes, and so on, without any chance of being independent.

    In order to arrive to a truly evidence based medicine or any other science, we need truly objective observers.
    A truly objective observer is one that is "outside of oneself", without any self-calculations, totally unbiased without any influence.

    Such a state can only be achieved in a circle, where a group of scientists create a completely equal, mutual relationship, where each agrees to give up his/her own ideas for accepting the ideas and opinions of others and in this way they can reveal, build something completely new in between them, as if their mutual "nullifications" towards each other opened a new channel.
    We need to start building such circles not only in science but at any place where decisions have to be made in an objective fashion.

    This obviously needs a "lead in" time, hard work, and gradual development since such a mutually 'self-less" work is against our nature. We have to find some very valid positive motivation to encourage people to try the method.

  5. CommentedRajan Bhardvaj

    The combined approach makes sense and one hopes that the EBM had not imagined a rigid practice of medicine. There is evidence from other domains including in international development that best outcomes result when where human judgment is exercised "...freedom to adapt and respond improves results ...esp. for complex projects.... " http://t.co/A6K8vBYhv3.

    At the same time, there are many cases where the de facto practices are just plain wrong or undertaken with regard to financial benefits rather the patients best interest. It seems to me that care should not only be informed by the available evidence and judgement but that we should collect and analyze post care data for efficacy and safety.

  6. CommentedRajan Bhardvaj

    The combined approach makes sense and one hopes that the EBM had not imagined a rigid practice of medicine. There is evidence from other domains including in international development that best outcomes result when where human judgment is exercised "...freedom to adapt and respond improves results ...esp. for complex projects.... " http://t.co/A6K8vBYhv3.

    At the same time, there are many cases where the de facto practices are just plain wrong or undertaken with regard to financial benefits rather the patients best interest. It seems to me that care should not only be informed by the available evidence and judgement but that we should collect and analyze post care data for efficacy and safety.

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