Jun 10, 2017

Evidence-based medicine or scientific medicine, same difference

According to Gordon Guyatt and David Sackett the first term for evidence-based medicine was scientific medicine. But they encountered opposition for the use of this term from the basic-science faculty:

Evidence-based medicine grew out of critical appraisal. When Gordon Guyatt, currently a professor of epidemiology and biostatistics and medicine at McMaster University, took over as director of the internal medicine residency program at McMaster in 1990, he wanted to change the program so that physicians managed patients based not on what authorities told them to do but on what the evidence showed worked. He needed a name, and the first was “scientific medicine.” The faculty reacted against this name with rage, arguing that basic scientists did scientific medicine. The next name was “evidence-based medicine”...

Subsequently, JAMA (through one of us, D.R.) established relationships with Sackett and Guyatt that led eventually to 2 pioneering series of articles in JAMA. The first was The Rational Clinical Examination,12,13 which was intended “to make a science out of taking a history and doing an examination.” These enterprises are fundamental to medicine but had not been scientifically studied. The second was the Users’ Guides to the Medical Literature, which was designed to help clinicians keep up to date by enabling them to interpret the burgeoning medical literature and to facilitate clinical decisions based on evidence from the medical literature rather than hope or authority.14

It is important to remember the origin of the framework as envisioned by Guyatt in his 1991 article and how evidence-based medicine was conceptualized from skepticism of certain practices at that time:

The way of the future described above depicts an important advance in the inclusion of new evidence into clinical practice. Clinicians were formerly taught to look to authority (whether a textbook, an expert lecturer, or a local senior physician) to resolve issues of patient management. Evidence-based medicine uses additional strategies, including quickly tracking down publications of studies that are directly relevant to the clinical problem, critically appraising these studies, and applying the results of the best studies to the clinical problem at hand. It may also involve applying the scientific method in determining the optimal management of the individual patient(3).

For the clinician, evidence-based medicine requires skills of literature retrieval, critical appraisal, and information synthesis. It also requires judgment of the applicability of evidence to the patient at hand and systematic approaches to make decisions when direct evidence is not available. The primary purpose of ACP Journal Club is to help make evidence-based medicine more feasible for internists by extracting new, sound clinical evidence from the morass of the biomedical literature so that practitioners can get at it.

When certain practices claim to be scientific it is important to consider what exactly do they mean by scientific. The practice of science is characterized by skepticism, independent critical thinking, genuine inquiry, acknowledgment of uncertainty, constructive valid criticism, and more. These appear to have been some of the goals of EBM practice as per its original conceptualization. Also, in a 1992 article Guyatt et al. placed EBM as a paradigm shift, quoting Thomas Kuhn's work on scientific revolutions:

Thomas Kuhn has described scientific paradigms as ways of looking at the world that define both the problems that can legitimately be addressed and the range of admissible evidence that may bear on their solution.4 When defects in an existing paradigm accumulate to the extent that the paradigm is no longer tenable, the paradigm is challenged and replaced by a new way of looking at the world. Medical practice is changing, and the change, which involves using the medical literature more effectively in guiding medical practice, is profound enough that it can appropriately be called a paradigm shift.

Furthermore, in a 2017 article by Djulbegovic and Guyatt, Kuhn's paradigm shift is used again to describe the contrast between EBM and the old ways of practicing medicine.

As discussed above, we see EBM as a socially constructed phenomenon in terms of Kuhn’s (new) scientific paradigm addressing the crisis in the practice of medicine that for centuries has relied almost exclusively on the subjective opinions of experts. EBM offers a new set of habits and ways of practicing medical science (Kuhn’s shared sets of values).

But if we look into the history of medicine we can find many examples where science has corrected medical practice. This is not a strange phenomenon in the world of science. The separation of science from non-science is known as the problem of demarcation. This problem has been instrumental in finding out what practices set science apart from other forms of practices that only proclaim to be scientific. Although a perfect demarcation criteria has not been discovered, philosophers and historians have been been successful in discovering certain distinctive practices between the two. In a BBC radio broadcast from 1973 Imre Lakatos, a philosopher of science, differentiated science and other practices that are only based on beliefs in the following manner:

Many philosophers have tried to solve the problem of demarcation in the following terms: a statement constitutes knowledge if sufficiently many people believe it sufficiently strongly. But the history of thought shows us that many people were totally committed to absurd beliefs. If the strengths of beliefs were a hallmark of knowledge, we should have to rank some tales about demons, angels, devils, and of heaven and hell as knowledge. Scientists, on the other hand, are very sceptical even of their best theories. Newton’s is the most powerful theory science has yet produced, but Newton himself never believed that bodies attract each other at a distance. So no degree of commitment to beliefs makes them knowledge. Indeed, the hallmark of scientific behaviour is a certain scepticism even towards one’s most cherished theories. Blind commitment to a theory is not an intellectual virtue: it is an intellectual crime.

Thus a statement may be pseudoscientific even if it is eminently ‘plausible’ and everybody believes in it, and it may be scientifically valuable even if it is unbelievable and nobody believes in it. A theory may even be of supreme scientific value even if no one understands it, let alone believes in it.

The cognitive value of a theory has nothing to do with its psychological influence on people’s minds. Belief, commitment, understanding are states of the human mind. But the objective, scientific value of a theory is independent of the human mind which creates it or understands it. Its scientific value depends only on what objective support these conjectures have in facts.

This parallels what evidence-based medicine stands for, as the name implies it is based on the evidence and not on what a person or a group of people believe. This is in contrast on the notion that it is a socially constructed paradigm as stated by Guyatt and Djulbegovic. In the same broadcast Lakatos adds:

What, then, is the hallmark of science? Do we have to capitulate and agree that a scientific revolution is just an irrational change in commitment, that it is a religious conversion? Tom Kuhn, a distinguished American philosopher of science, arrived at this conclusion after discovering the naivety of Popper’s falsificationism. But if Kuhn is right, then there is no explicit demarcation between science and pseudoscience, no distinction between scientific progress and intellectual decay, there is no objective standard of honesty. But what criteria can he then offer to demarcate scientific progress from intellectual degeneration?

More than just what a group of individuals practice at a certain point in history, EBM seems to be in the history of medicine as well. In a 1997 article Sackett states that evidence based medicine is not new and has its philosophical roots in the 19th century. Sackett writes:

Evidence based medicine, whose philosophical origins extend back to mid-19th century Paris and earlier, remains a hot topic for clinicians, public health practitioners, purchasers, planners, and the public.

The history of medicine is filled with examples of practices that were debunked with the help of the scientific method. These practices were demonstrated either to be harmful or not beneficial for patients, for example bloodletting. Even to this day we use the scientific method to help us determine which practices are beneficial and which ones are not. It appears then that the practice evidence-based medicine may just be an attempt to bring the scientific method to the forefront of medical practice. Even to this day we see how science corrects the practice of medicine, for example:

There are in fact multiple examples of doctors being convinced that a treatment is the right thing to do, only to later conclude the opposite. These medical reversals might have been originally based on flawed theory and small studies, for example: steroids and prophylactic hyperventilation for traumatic brain injury, the military anti-shock trousers suit for hypovolaemic shock, and aggressive volume resuscitation for shock associated with penetrating truncal trauma. Similarly, there are many examples of positive results from trials based on surrogate measures (i.e. disease-oriented outcomes) that are subsequently overturned by trials based on clinically meaningful (i.e. patient-oriented) outcomes, such as high-dose steroids for spinal cord injury, calcium in cardiac arrest, cyclo-oxygenase-2 enzyme (COX-2) inhibitors, early decompressive craniectomy in traumatic brain injury, vest CPR for out-of-hospital cardiac arrest, and drotrecogin alfa for sepsis. These are now discredited, but at the time, they seemed like a logical and good idea.

Unfortunately, a logical theory often trumps reality.[2] Many medical reversals involve a standard of care that has been promoted and based on our incomplete or flawed understanding of the pathophysiology of the condition.[3] Maybe half of these practices are wrong.[1] Perhaps more than half. In these cases, it is evident that clinicians have been using medications or procedures, such as those outlined above, in vain and causing harm. Yet, these same treatments have been promoted by professional bodies and consensus guidelines.[3] Indeed, exaggerated results in medical literature have reached epidemic proportions in recent years.[4] Many treatments that claim a benefit have turned out not to be true. Examples of this are increasingly being published, and papers reporting this phenomenon are becoming common.[5] Moreover, even when the effects are genuine and confirmed on replication of the study, their true magnitude is typically smaller than originally claimed.[4, 6] This might be due to underlying publication bias with journals preferring positive data over null results, and the selective reporting of results. As Richard Palmer states: ‘We cannot escape the troubling conclusion that some – perhaps many – cherished generalities are at best exaggerated in their biological significance and at worst a collective illusion nurtured by strong a priori beliefs often repeated.’[6] Scientists frequently find ways to confirm their preferred hypothesis, disregarding what they do not want to see.[6]

Fatovich, D. M. (2013), Medical reversal: What are you doing wrong for your patient today?. Emerg Med Australas, 25: 1–3. doi:10.1111/1742-6723.12044

Our medical knowledge is very much scientific knowledge; it is incomplete, fallible, and perpetually in revision. But it's the best method we have to understand how the world works. I believe Neurath gives an excellent metaphor on scientific knowledge:

There is no way to establish fully secured, neat protocol statements as starting points of the sciences. There is no tabula rasa. We are like sailors who have to rebuild their ship on the open sea, without ever being able to dismantle it in dry-dock and reconstruct it from its best components. Only metaphysics can disappear without a trace. Imprecise ‘verbal clusters’ [Ballungen] are somehow always part of the ship. If imprecision is diminished at one place, it may well re-appear at another place to a stronger degree. (Neurath 1932/1983, 92)

Cat, Jordi, "Otto Neurath", The Stanford Encyclopedia of Philosophy (Winter 2014 Edition), Edward N. Zalta (ed.)

If evidence-based medicine or scientific medicine as originally conceptualized is what's desired for practice due to its successful record, then what needs to be taught is how science works, not just its products. As stated by Norris beliefs will not serve us well in becoming intellectually independent.

Unless individuals have some grounds for distinguishing the level of justification that they have for their various beliefs, then they are as likely to act upon false beliefs as upon true ones. Rote learning, by definition, is learning that provides no justification for what is learned, and even pays scant attention to its meaning. Furthermore, rote learning as a goal of science education is unacceptable on moral grounds. To ask of other human beings that they accept and memorize what the science teacher says, without any concern for the meaning and justification of what is said, is to treat those human beings with disrespect and is to show insufficient care for their welfare. It treats them with disrespect, because students exist on a moral par with their teachers, and therefore have a right to expect from their teachers reasons for what the teachers wish them to believe. It shows insufficient care for the welfare of students, because possessing beliefs that one is unable to justify is poor currency when one needs beliefs that can most reliably guide action.

Evidence-based medicine, as originally conceptualized, is just medical practice using the scientific method.

Bold text represent my emphasis

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1. You should attempt to re-express your target’s position so clearly, vividly, and fairly that your target says, “Thanks, I wish I’d thought of putting it that way.
2. You should list any points of agreement (especially if they are not matters of general or widespread agreement).
3. You should mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Daniel Dennett, Intuition pumps and other tools for thinking.

Valid criticism is doing you a favor. - Carl Sagan