Science-Based Medicine

Homeopathy and Science: Discussion, Summary and Conclusions

I was not surprised by a couple of the dissenting comments after Part IV of this blog. One writer worried that I had neglected, presumably for nefarious reasons, to cite replications of Benveniste’s results; another cited several examples of “positive” homeopathy studies that I had failed to mention. I answered some of those points here. I am fully aware of such “positive” reports, including those seeming to support Benveniste. I didn’t cite them, but not in some futile hope of concealing their existence from the watchful eyes of the readership. I also didn’t cite several “negative” reports, including an independent, disconfirming report of one of the claims of David Reilly, whose words began this series,* and the most recent of several reviews (referenced here) to conclude that “the clinical effects of homoeopathy are placebo effects.” I didn’t cite those reports for the same reasons that I didn’t cite the “positive” studies: they are mere footnotes to the overwhelming evidence against homeopathy.

To explain why, it will be necessary to discuss some of the strengths and weaknesses of the project known as “Evidence-Based Medicine.”

Continue Reading »

The Main Event: Novella vs. Katz

The remainder of the Symposium comprised two panels. The first was what I had come to see: a Moderated Discussion on Evidence and Plausibility in the Context of CAM Research and Clinical Practice, featuring our Founder, Steve Novella, who is also Assistant Professor of Neurology at Yale; and David Katz, the speaker who had borne the brunt of the criticism after the 2008 conference (as I wrote in Part I). According to the Symposium syllabus, he is:

David L. Katz, MD, MPH, FACPM, FACP, an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care. He is a board certified specialist in both Internal Medicine, and Preventive Medicine/Public Health, and Associate Professor (adjunct) in Public Health Practice at the Yale University School of Medicine. Katz is the Director and founder (1998) of Yale University’s Prevention Research Center; Director and founder of the Integrative Medicine Center at Griffin Hospital (2000) in Derby, CT; founder and president of the non-profit Turn the Tide Foundation; and formerly the Director of Medical Studies in Public Health at the Yale School of Medicine for eight years. He currently serves as Chair of the Connecticut Chapter of the Partnership to Fight Chronic Disease and represents Yale University on the Steering Committee of the Consortium of Academic Health Centers for Integrative Medicine.

The syllabus had excerpted that statement from a much larger, remarkable document, which I urge you to review.

I will attempt to report the Moderated Discussion as neutrally as possible, as though I were a disinterested journalist (don’t worry: later I’ll rail).

Continue Reading »

Review

This is the second post in a series* prompted by an essay by statistician Stephen Simon, who argued that Evidence-Based Medicine (EBM) is not lacking in the ways that we at Science-Based Medicine have argued. David Gorski responded here, and Prof. Simon responded to Dr. Gorski here. Between that response and the comments following Dr. Gorski’s post it became clear to me that a new round of discussion would be worth the effort.

Part I of this series provided ample evidence for EBM’s “scientific blind spot”: the EBM Levels of Evidence scheme and EBM’s most conspicuous exponents consistently fail to consider all of the evidence relevant to efficacy claims, choosing instead to rely almost exclusively on randomized, controlled trials (RCTs). The several quoted Cochrane abstracts, regarding homeopathy and Laetrile, suggest that in the EBM lexicon, “evidence” and “RCTs” are almost synonymous. Yet basic science or preliminary clinical studies provide evidence sufficient to refute some health claims (e.g., homeopathy and Laetrile), particularly those emanating from the social movement known by the euphemism “CAM.”

It’s remarkable to consider just how unremarkable that last sentence ought to be. EBM’s founders understood the proper role of the rigorous clinical trial: to be the final arbiter of any claim that had already demonstrated promise by all other criteria—basic science, animal studies, legitimate case series, small controlled trials, “expert opinion,” whatever (but not inexpert opinion). EBM’s founders knew that such pieces of evidence, promising though they may be, are insufficient because they “routinely lead to false positive conclusions about efficacy.” They must have assumed, even if they felt no need to articulate it, that claims lacking such promise were not part of the discussion. Nevertheless, the obvious point was somehow lost in the subsequent formalization of EBM methods, and seems to have been entirely forgotten just when it ought to have resurfaced: during the conception of the Center for Evidence-Based Medicine’s Introduction to Evidence-Based Complementary Medicine.

Thus, in 2000, the American Heart Journal (AHJ) could publish an unchallenged editorial arguing that Na₂EDTA chelation “therapy” could not be ruled out as efficacious for atherosclerotic cardiovascular disease because it hadn’t yet been subjected to any large RCTs—never mind that there had been several small ones, and abundant additional evidence from basic science, case studies, and legal documents, all demonstrating that the treatment is both useless and dangerous. The well-powered RCT had somehow been transformed, for practical purposes, from the final arbiter of efficacy to the only arbiter. If preliminary evidence was no longer to have practical consequences, why bother with it at all? This was surely an example of what Prof. Simon calls “Poorly Implemented Evidence Based Medicine,” but one that was also implemented by the very EBM experts who ought to have recognized the fallacy.

There will be more evidence for these assertions as we proceed, but the main thrust of Part II is to begin to respond to this statement from Prof. Simon: “There is some societal value in testing therapies that are in wide use, even though there is no scientifically valid reason to believe that those therapies work.”

Continue Reading »

NB: If you haven’t yet read Part 1 of this blog, please do so now; Part 2 will not summarize it.

…

At the end of Part 1, I wrote:

We do not need formal statistics or a new, randomized trial with a larger sample size to justify dismissing the Gonzalez regimen.

In his editorial for the JCO, Mark Levine made a different argument:

Can it be concluded that [the] study proves that enzyme therapy is markedly inferior? On the basis of the study design, my answer is no. It is not possible to make a silk purse out of a sow’s ear.

That conclusion may be correct in the EBM sense, but it misses the crucial point of why the trial was (ostensibly) done: to determine, once and for all, whether there was anything to the near-miraculous claims that proponents had made for a highly implausible “detoxification” regimen for cancer of the pancreas. Gonzalez himself had admitted at the trial’s inception that nothing short of an outcome matching the hype would do:

DR. GONZALEZ: It’s set up as a survival study. We’re looking at survival.

SPEAKER: Do you have an idea of what you’re looking for?

DR. GONZALEZ: Well, Jeff [Jeffrey White, the director of the Office of Cancer Complementary and Alternative Medicine at the NCI—KA] and I were just talking a couple weeks ago. You know, to get any kind of data that would be beyond criticism is—-always be criticism, but at least three times.

You would want in the successful group to be three times — the median to be three times out from the lesser successful groups.

So, for example, if the average survival with chemo, which we suspect will be 5 months, you would want my therapy to be at least — the median survival to be at least 15, 16, 17 months, as it was in the pilot study.

We’re looking for a median survival three times out from the chemo group to be significant.

Recall that the median survival in the Gonzalez arm eventually turned out to be 4.3 months.

Continue Reading »

In Parts I and II of this series* we saw that from 2000 to 2002, key members of the Harvard Medical School “CAM” program, including the Director, had promoted quackery to the legislature of the Commonwealth of Massachusetts. We also saw other explicit or tacit promotions by Harvard institutions and professors, and embarrassing examples of such promotions on InteliHealth, a consumer health website ostensibly committed to “providing credible information from the most trusted sources, including Harvard Medical School….”

Those points were made in an essay that I sent in the spring of 2002 to Daniel Federman, the Senior Dean for Alumni Relations and Clinical Teaching at Harvard Medical School (HMS). I also sent Dr. Federman a treatise on homeopathy, including several examples of credulous Harvard professors and misrepresentations aimed at students, patients, and the public. Much of the content of that treatise has been covered by the series on homeopathy† with which I began my stint here on SBM, so here I’ll post only the parts relevant to promotions by academic physicians, including those at Harvard. There is a bit of redundancy involving InteliHealth, but please bear with me if you’ve made it this far; the discussion will be meatier than the short summary in Part II.

Continue Reading »

Background: the distinction between EBM and SBM

An important theme on the Science-Based Medicine blog, and the very reason for its name, has been its emphasis on examining all the evidence—not merely the results of clinical trials—for various claims, particularly for those that are implausible. We’ve discussed the distinction between Science-Based Medicine (SBM) and the more limited Evidence-Based Medicine (EBM) several times, for example here (I began my own discussion here and added a bit of formality here, here, and here). Let me summarize by quoting John Ioannidis:

…the probability that a research finding is indeed true depends on the prior probability of it being true (before doing the study), the statistical power of the study, and the level of statistical significance.

EBM, in a nutshell, ignores prior probability† (unless there is no other available evidence) and falls for the “p-value fallacy”; SBM does not. Please don’t bicker about this if you haven’t read the links above and some of their own references, particularly the EBM Levels of Evidence scheme and two articles by Steven Goodman (here and here). Also, note that it is not necessary to agree with Ioannidis that “most published research findings are false” to agree with his assertion, quoted above, about what determines the probability that a research finding is true.

The distinction between SBM and EBM has important implications for medical practice ethics, research ethics, human subject protections, allocation of scarce resources, epistemology in health care, public perceptions of medical knowledge and of the health professions, and more. EBM, as practiced in the 20 years of its formal existence, is poorly equipped to evaluate implausible claims because it fails to acknowledge that even if scientific plausibility is not sufficient to establish the validity of a new treatment, it is necessary for doing so.

Thus, in their recent foray into applying the tools of EBM to implausible health claims, government and academic investigators have made at least two, serious mistakes: first, they have subjected unwary subjects to dangerous but unnecessary trials in a quest for “evidence,” failing to realize that definitive evidence already exists; second, they have been largely incapable of pronouncing ineffective methods ineffective. At best, even after conducting predictably disconfirming trials of vanishingly unlikely claims, they have declared such methods merely “unproven,” almost always urging “further research.” That may be the proper EBM response, but it is a far cry from the reality. As I opined a couple of years ago, the founders of the EBM movement apparently “never saw ‘CAM’ coming.”

Continue Reading »

OK, I admit that I pulled a fast one. I never finished the last post as promised, so here it is.

Cochrane Continued

In the last post I alluded to the 2006 Cochrane Laetrile review, the conclusion of which was:

This systematic review has clearly identified the need for randomised or controlled clinical trials assessing the effectiveness of Laetrile or amygdalin for cancer treatment.

I’d previously asserted that this conclusion “stand[s] the rationale for RCTs on its head,” because a rigorous, disconfirming case series had long ago put the matter to rest. Later I reported that Edzard Ernst, one of the Cochrane authors, had changed his mind, writing, “Would I argue for more Laetrile studies? NO.” That in itself is a reason for optimism, but Dr. Ernst is such an exception among “CAM” researchers that it almost seemed not to count.

Until recently, however, I’d only seen the abstract of the Cochrane Laetrile review. Now I’ve read the entire review, and there’s a very pleasant surprise in it (Professor Simon, take notice). In a section labeled “Feedback” is this letter from another Cochrane reviewer, which was apparently added in August of 2006, well before I voiced my own objections:

Continue Reading »

This is actually the second entry in this series;† the first was Part V of the Homeopathy and Evidence-Based Medicine series, which began the discussion of why Evidence-Based Medicine (EBM) is not up to the task of evaluating highly implausible claims. That discussion made the point that EBM favors equivocal clinical trial data over basic science, even if the latter is both firmly established and refutes the clinical claim. It suggested that this failure in calculus is not an indictment of EBM’s originators, but rather was an understandable lapse on their part: it never occurred to them, even as recently as 1990, that EBM would soon be asked to judge contests pitting low powered, bias-prone clinical investigations and reviews against facts of nature elucidated by voluminous and rigorous experimentation. Thus although EBM correctly recognizes that basic science is an insufficient basis for determining the safety and effectiveness of a new medical treatment, it overlooks its necessary place in that exercise.

This entry develops the argument in a more formal way. In so doing it advocates a solution to the problem that has been offered by several others, but so far without real success: the adoption of Bayesian inference for evaluating clinical trial data.
Continue Reading »

During the most recent kerfuffle about whether or not Evidence-Based Medicine can legitimately claim to be science-based medicine, it became clear to me that a whole, new round of discussion and documentation is necessary. This is frustrating because I’ve already done it several times, most recently less than a year ago. Moreover, I’ve provided a table of links to the whole series at the bottom of each post*…Never mind, here goes, and I hope this will be the last time it is necessary because I’ll try to make this the “go to” series of posts for any future such confusions.

The points made in this series, most of which link to posts in which I originally made them, are in response to arguments from statistician Steve Simon, whose essay, Is there something better than Evidence Based Medicine out there?, was the topic of Dr. Gorski’s rebuttal on Monday of this week, and also from several of the comments following that rebuttal. Mr. Simon has since revised his original essay to an extent, which I’ll take into account. I’ll frame this as a series of assertions by those who doubt that EBM is deficient in the ways that we at SBM have argued, followed in each case by my response.

First, a disclaimer: I don’t mean to gang up on Mr. Simon personally; others hold opinions similar to his, but his essay just happens to be a convenient starting point for this discussion. FWIW, prior to this week I perused a bit of his blog, after having read one of his comments here, and found it to be well written and informative.

Continue Reading »

Part I of this blog† summarized the origin of homeopathy, invented in 1790 by Samuel Christian Hahnemann. It discussed Hahnemann’s first two “homœopathic laws of nature,” similia similibus curantur (like cures like) and the “law of infinitesimals,” and showed that his rationales for each have long been refuted. Hahnemann proclaimed a third doctrine, the “law of psora” ["itch"], said by him to be “the mother of all true chronic diseases except the syphilitic and sycotic.”[1] Oddly, it seems to have been forgotten.

Part II gives Hahnemann the opportunity to explain his assertions more thoroughly, as is his due. It considers those assertions from the vantage point of modernity, as is ours.

“Leave None of them Uncured”

According to Hahnemann, homeopathy is a panacea:

“Now, however, in all careful trials, pure experience, the sole and infallible oracle of the healing art, teaches us that actually that medicine which, in its action on the healthy human body, has demonstrated its power of producing the greatest number of symptoms similar to those observable in the case of disease under treatment, does also, in doses of suitable potency and attenuation, rapidly, radically and permanently remove the totality of the symptoms of this morbid state, that is to say, the whole disease present, and change it into health; and that all medicines cure, without exception, those diseases whose symptoms most nearly resemble their own, and leave none of them uncured.”[2]

How might this happen?

Continue Reading »