Seven philosophical criticisms of Evidence-Based Medicine and evidence hierarchiesHow Big Pharma hijacked Evidence-Based Medicine, Part IIEditor’s note: Once again this article is too long for most email systems so please click on the headline to read the full piece on the Substack site. Introduction In my last article, I presented ten practical and material criticisms of Evidence-Based Medicine (EBM). But there are even larger metaphysical, ontological, and epistemological problems with EBM. Numerous authors make the case that EBM and evidence hierarchies elide important debates in the philosophy of medicine. In this article I will review seven philosophical debates in connection with EBM and evidence hierarchies including: 1. Hierarchies are not how causation in science is usually constructed; 2. Evidence and interpretation are two different things; 3. The inferential gap may be unbridgeable; 4. Bayesian statistics has long since proven superior to the frequentist statistics relied on by RCTs; 5. Science can never prove hypotheses, only refute them; 6. Actual medical practice is necessarily pragmatic and different from the objectivism of EBM; and 7. Medicine is a practice not a science per se. 1. Hierarchies are not how causation in science is constructed Several authors have noted that EBM tends to overlook and ignore the contributions of basic science (also called “bench” or “fundamental” science and I will use these three terms synonymously in this section). Bench research is defined as “any research done in a controlled laboratory setting using nonhuman subjects. The focus is on understanding cellular and molecular mechanisms that underlie a disease or disease process” (“Bench research”, n.d.). Merriam Webster’s Dictionary defines basic science as, “any one of the sciences (such as anatomy, physiology, bacteriology, pathology, or biochemistry) fundamental to the study of medicine” (“basic science”, n.d.). The CEBM evidence hierarchy lists basic science as the fifth level of evidence, below the threshold suggested by Strauss et al. (2005) and others as even worth reading. To be clear, the CEBM and other evidence hierarchies are not excluding bench science entirely from the study of medicine — they are proscribing the consideration of bench science by doctors when they make clinical decisions (presumably others, namely pharmaceutical companies and academic researchers would be free to continue with a more comprehensive approach). Excluding basic science in this way is an odd choice because basic science has always been an essential component of establishing causation. Bluhm (2005) writes,
Bluhm (2005) argues that EBM should move from hierarchies of evidence to “networks of evidence” in which both epidemiology and lab-based biochemistry work hand in hand (p. 535). It is a fine point as far as it goes, but it strikes me that one could push this idea of networks of evidence even further — to include the subjective wisdom of both doctors and patients as well. I will elaborate on this point later in the article. Rawlins (2008) writes:
Goldenberg (2009) argues that the degradation of pathophysiology in evidence hierarchies is unwarranted “as pathophysiology often provides more fundamental understanding of causation and is in no way scientifically inferior” (p. 180). La Caze (2011) voices alarm that evidence hierarchies overlook the contributions of basic science. As pointed out above, basic science is usually assigned to the lower tiers of evidence hierarchies. While the assignments to the different tiers are rationalized based on reference to “quality” in fact, “proponents of EBM provide little justification for placing basic science so low in EBM’s hierarchy” (La Caze, 2011, p. 96). “Proponents of EBM urge clinicians to base decisions on the outcomes of large randomised studies rather than the mechanistic understanding of pharmacology and physiology provided by basic science” (La Caze, 2011, p. 83). While it is true that leaders of the EBM movement such as Sackett et al. (1996) mentioned integrating the totality of evidence in early statements on EBM, in practice, evidence hierarchies have become a sorting mechanism for what studies to read (RCTs) and what evidence to ignore (everything else). Contrary to holistic approaches to medicine that recommend evaluating the totality of evidence, in EBM, “evidence from randomised studies is taken to trump evidence from lower down the hierarchy, including evidence from basic medical science” (La Caze, 2011, p. 84): La Caze (2011), in his defense of basic science, draws attention to an issue that will be explored in greater depth below — the problem of inference from a sample population to a particular patient (La Caze refers to this as the problem of “external validity” and Upshur (2005) below refers to it as the “inferential gap”).
The various branches of science and medicine usually work together as an interwoven system so it is strange for EBM to privilege one strand of the system over all others.
The denigration of bench science is yet another example of how EBM overlooks systems while privileging certain parts and certain actors. 2. Evidence and interpretation are two different things Upshur and Tracy (2004) point out that evidence itself does not indicate what should be done; the interpretation of evidence is key. But EBM elides this distinction between evidence and interpretation and implies that proper evidence (in their view, RCTs) is dispositive. In the process they smuggle in, without debate, a deterministic philosophy, which runs counter to actual medical practice. Upshur and Tracy (2004) take pains to correct the deterministic view of evidence that has emerged via EBM:
But actually applying the evidence requires a different set of skills:
Upshur’s views on evidence also show up in this correspondence with Gupta (2003):
Gupta (2003) continues:
If one is looking to solve complex problems in medicine, the relationship between evidence and interpretation matters enormously. If one is just looking to sell profitable drugs, that relationship is not as important. The fact that EBM has not adequately addressed the fundamental distinction between evidence and interpretation is troubling indeed. 3. The inferential gap may be unbridgeable Upshur (2005) points out that the sample population used in trials is often quite different from the actual population that uses a particular treatment. Doctors are expected to extrapolate from a sample population to their particular patient — but Upshur (2005) argues that such deduction (sometimes also referred to as extrapolation or inference) is more problematic than it would appear. He writes:
Upshur (2005) shows that medicine faces an irreducible problem in that average outcomes in RCTs do not indicate what treatment is appropriate for the individual patient. But EBM as currently constructed ignores this “inferential gap.” He writes:
This inferential gap is unlikely to ever be bridged because there is infinite variety in the human population so responses to medical interventions will always vary as well. Bayesian statistics might help narrow the gap a bit (see next section) as it allows one to continually refine estimates as new evidence becomes available (conditional probabilities that affect the prior probability of the hypothesis). But even with Bayesian statistics, the best one can come up with are probabilities, not the deterministic thinking of EBM. These are extraordinary debates at the core of the philosophy of medicine — and it is exactly these sorts of debates that EBM proponents circumvent in making RCTs the sole tool for clinical decisions. 4. Bayesian statistics has long since proven superior to the frequentist approach relied upon by RCTs Worral (2002) is withering in his critique of the over-reliance on RCTs within evidence-based medicine. The picture he paints is a battle between frequentist statisticians and Bayesian statisticians (and philosophers) over the epistemological basis of EBM. He notes that frequentist statisticians have elevated RCTs to the top of the evidence hierarchy as a sort of panacea for overcoming research bias but that such a ranking is not warranted by the evidence. Worrall (2002) writes that three arguments have traditionally been used in favor of randomization:
Worrall (2002) makes the case that none of these arguments withstands close examination. Ronald Fisher was an English statistician whose insights helped to create modern statistical science (Hald, 1998). Fisher argued that randomisation was the only means by which “the validity of the test of significance can be guaranteed” (1947, in Worrall, 2002, p. 321). Worrall (2002) responds to this line of reasoning by writing,
In 2008, Michael Rawlins gave the annual Harveian Oration at the Royal College of Physicians of London where he challenged many tenets of EBM. He stated his view that, “Decisions about the use of therapeutic interventions, whether for individuals or entire healthcare systems, should be based on the totality of available evidence. The notion that evidence can be reliably or usefully placed in ‘hierarchies’ is illusory” (Rawlins, 2008, p. 579). It was a direct challenge to a healthcare system increasingly designed around the use of EBM and evidence hierarchies. As part of his address, he also politely sided with the Bayesians over the frequentists:
But he notes that “regulatory authorities have sometimes been hesitant to concede that Bayesian approaches may have advantages” (Berry et al. 2005, in Rawlins, 2008, p. 582). 5. “Science can never prove hypotheses, only refute them...” (The Popperians vs. EBM) Eyal Shahar (1997) similarly challenges the epistemic basis of EBM — but from a Popperian perspective. Shahar, a doctor and epidemiologist, sees EBM as an end run around complicated epistemological issues that some scientists would rather not discuss. He writes: “‘evidence-based medicine’ is at best a meaningless substitute for ‘medicine’ and, at worst, a disguise for a new version of authoritarianism in medical practice” (Shahar, 1997, p. 110). He continues:
For Popperians, the problem with EBM goes beyond the general and technical problems noted by others. Rather the problem is that the inductive method relied upon by EBM (inferring from a clinical trial to a particular patient) is not a valid methodology. Shahar (1997) writes,
While Upshur (2005) was troubled by EBM’s leaps across the inferential gap, Shahar (1997) goes further by arguing that this gap can never be closed completely. Popperians similarly reject the frequentist assumptions that underlie RCTs:
Shahar (1997) argues that given a heterogeneous population, personalized medicine is the only logically justified approach to evidence:
For Shahar (1997) EBM is an illegitimate attempt to elide the uncomfortable realities of the uncertainty that comes with medical practice:
Shahar (1997) concludes by writing:
Based on the evidence presented in Chapter 5 of my doctoral thesis we already have the answer to Shahar’s question. Practically speaking, the evidence generated by pharmaceutical companies through their contracts with overseas (usually Chinese) CROs, written up by ghost writers employed by pharmaceutical companies, and published in scientific journals that often have their own financial conflicts of interest, is the evidence that EBM tells doctors to rely upon. EBM is a corporate takeover of medicine by stealth with only a handful of critics raising questions about its troublesome context and implications. 6. The Pragmatists vs. EBM The pragmatic school in the philosophy of medicine also takes exception to what they call the objectivist ontology of EBM. Pragmatism is defined as “a philosophy emphasizing practical applications and consequences of beliefs and theories, that the meaning of ideas or things is determined by the testability of the idea in real life” (pragmatism, n.d.). Objectivism is defined as “one of several doctrines holding that all reality is objective and external to the mind and that knowledge is reliably based on observed objects and events” (objectivism, n.d.). The irony is that EBM sees itself as a pragmatic movement. But Goldenberg (2009) argues that EBM is actually an objectivist philosophy.
Goldenberg (2009) argues that EBM’s objectivist tendencies make it ill-suited to the demands of day-to-day medicine.
Goldenberg describes a certain paradox to EBM — on the one hand its proponents appeal to a certain pure standard of objectivity (via RCTs) while on the other hand ignoring evidence that RCTs are not as objective as they seem.
One of the things I find so troublesome about EBM is not its positivism or objectivism per se, but rather that it displays a certain corporate positivism and corporate objectivism. What I mean is that in EBM, (mostly) corporate-derived data is granted exclusive privileges for decision making in spite of evidence suggesting it is of low quality, while other valid but often non-corporate methods, such as observational studies or registries, are dismissed outright. Goldenberg argues that the “absolutist search for certainty can explain the appeal and rapid uptake of EBM” (p. 181).
It is not that science and medicine could never be tools for liberation. It is that actually existing science and medicine in the U.S., for the most part, are monopoly capitalist science and medicine that elevate profits over the well-being of people, which puts them in conflict with their own stated methods and principles. 7. Medicine as science vs. medicine as practice In How Doctors Think, Kathryn Montgomery (2006) argues that medicine is neither a science nor an art but a social science — specifically the development of practical reasoning which Aristotle called phronesis. She writes,
But medicine as science just does not fit the evidence of how doctors actually do their work according to Montgomery (2006).
Montgomery (2006) calls medicine a “practice” and proceeds to reintroduce ancient wisdom into the conversation. She writes,
If medicine at its best is properly thought of as a social and philosophical practice, EBM as currently taught interrupts that practice. EBM fixes medical practice to a frequentist, corporate ontology. By design, EBM quite explicitly turns off the multiple, conflicting, ever-changing ways of knowing and replaces them with a single corporatized channel, RCTs. Conclusion As with any successful marketing program, the words themselves are unobjectionable and pleasing: evidence-based medicine. But the actual program behind Evidenced-Based Medicine™ as practiced throughout the developed world over the last thirty years is corporate, captured, runs roughshod over essential debates in the philosophy of medicine, and promotes deadly junk science as the gold standard of science. Think about this: over the last three decades, the biggest blockbuster drugs include vaccines, SSRIs and other psychopharmaceuticals, and statins. All of them were licensed using EBM rubrics. And yet none of them have been shown to have more benefits than harms in the real world. EBM has turned allopathic medicine into a Potemkin Village — a pretty façade with almost nothing of substance behind it. The character arc of EBM is like reading a Greek tragedy or the Old Testament. A bunch of smart, seemingly well-intentioned people organized themselves to take over the practice of medicine. They wanted to make it better. It went well for a while but then hubris, greed, power, and corruption took over. Epidemiologists became a new priestly class and replaced science with dogmatism. Once unleashed, EBM became a runaway freight train. Now it is actively harming patients and destroying allopathic medicine in the name of saving it. We need not sacrifice our dignity, common sense, and rational faculties on the altar of EBM as Guyatt and others have done. Rigged RCTs are not evidence. Corporate science is not science. We need to return to the old ways. We must let doctors be doctors again, relying on evidence, experience, and intuition — phronesis as Aristotle taught us (and Kathryn Montgomery reminds us). And we must let parents be parents again. Personal sovereignty and responsibility are the foundation of medicine and society. No financially conflicted epidemiologist in an ivory tower thousands of miles away (or heaven help us, Washington D.C.) knows what’s best for a person. The era of corporate EBM is over and the future of medicine is decentralized, N-of-1, non-corporate, non-government, person-to-person, direct primary care, based on the totality of evidence, decency, life experience, and personal values. REFERENCES basic science. (n.d.). https://www.merriam-webster.com/dictionary/basic science bench research. (n.d.). https://web.archive.org/web/20181209194911/http://medical-dictionary.thefreedictionary.com/bench+research Bluhm, R. (2005). From Hierarchy to Network: a richer view of evidence for evidence-based medicine. Perspectives in Biology and Medicine, 48(4), 535-547. https://sci-hub.se/10.1353/pbm.2005.0082 objectivism. (n.d.) Farlex Partner Medical Dictionary. (2012). https://www.thefreedictionary.com/objectivism Goldenberg, M. J. (2009, Spring). Iconoclast or Creed?: Objectivism, Pragmatism, and the Hierarchy of Evidence. Perspectives in Biology and Medicine, 52(2). https://sci-hub.se/10.1353/pbm.0.0080 Gupta, M. (2003). A critical appraisal of evidence‐based medicine: some ethical considerations. Journal of Evaluation in Clinical Practice, 9(2), 111–121. https://sci-hub.se/https://doi.org/10.1046/j.1365-2753.2003.00382.x La Caze, A. (2011). The role of basic science in evidence-based medicine. Biology and Philosophy, 26(1), 81-98. Montgomery, K. (2006). How doctors think: Clinical judgment and the practice of medicine. Oxford University Press. https://global.oup.com/academic/product/how-doctors-think-9780195187120 pragmatism. (n.d.) Farlex Partner Medical Dictionary. (2012). http://medical-dictionary.thefreedictionary.com/pragmatism Rawlins, M. (2008, December). De Testimonio: on the evidence for decisions about the use of therapeutic interventions. Clinical Medicine, 8(6). http://doi.org/10.7861/clinmedicine.8-6-579 Sackett, D. L., Rosenberg, W. M. C., Gray, J. A. M., Haynes, R. B., & Richardson, W. S. (1996, January 13). Evidence based medicine: What it is and what it isn’t. British Medical Journal, 312(7023), 71–72. https://doi.org/10.1136/bmj.312.7023.71 Shahar, E. (1997). A Popperian perspective of the term ‘evidence-based medicine’. Journal of Evaluation in Clinical Practice, 3, 109-116. https://sci-hub.se/10.1046/j.1365-2753.1997.00092.x Upshur, R. E. G. and Tracy, C. S. (2004, Fall). Legitimacy, Authority, and Hierarchy: Critical Challenges for Evidence-Based Medicine. Brief Treatment and Crisis Intervention, 4(3), 197-204. http://doi.org/10.1093/brief-treatment/mhh018 Upshur, R. E. G. (2005, Autumn). Looking for rules in a world of exceptions: reflections on evidence-based practice. Perspectives in Biology and Medicine, 48(4), 477-489. https://sci-hub.se/10.1353/pbm.2005.0098 Worrall, J. (2002, September). What Evidence in Evidence-Based Medicine? Philosophy of Science, 69(S3), S316-S330. https://sci-hub.se/http://doi.org/10.1086/341855 Blessings to the warriors. 🙌 Prayers for everyone fighting to stop the iatrogenocide. 🙏 Huzzah for everyone building the parallel society our hearts know is possible. ✊ In the comments, please let me know what’s on your mind. As always, I welcome any corrections. You're currently a free subscriber to uTobian. For the full experience, upgrade your subscription. |
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