With the UK government considering a ban on the prescription of homeopathic remedies on the NHS, John Worrall examines the rationale for such a proposal and suggests that the decision is not as simple as it might initially seem.
Current NHS policy on homeopathy is that, while dedicated homeopathic clinics may not be NHS-funded, regular, GMC-registered practitioners may write NHS prescriptions for homeopathic “remedies”. The UK Government is currently considering a ban on such prescriptions – on the grounds that there is no “top quality” evidence that homeopathic “remedies” are in fact effective.
I am not convinced that such a ban would be a good idea.
Before those who know my unrelentingly pro-science, pro-rationality views swoon in shocked surprise let me say: first, I wholeheartedly endorse the view expressed by David Hume that “the rational man tailors his belief to the evidence”. Indeed I regard this general idea as a (practically important) statement of the “bleedin’ obvious”. OF COURSE, medicine just like any rational pursuit, should be based on evidence. Reasonable criticism of EBM (Evidence-Based Medicine) is targeted, not at the general idea, but at the overly narrow and mechanistic views of what “really counts” as evidence that EBM has sometimes been taken to endorse.
Secondly, the theories underlying homeopathy are as far from evidence-based as it is possible to be. The first is the “like treats like” theory: substances that in large amounts cause the symptoms of some condition C can ameliorate C when given in small amounts. Very small amounts (!), because the second theory holds that homeopathic substances become more potent, the more they are diluted and “succussed”, i.e. vigorously shaken. Indeed, homeopathic substances are alleged to be at their most potent when diluted beyond Avogadro’s number, so that with overwhelming probability not a single molecule of the “active” substance remains. Homeopaths suggest that the diluent may retain a “memory” of the late, lamented “active” substance. This suggestion might generously be described as fanciful – at least when judged from the standpoint of current science; and what other reasonable standpoint could there be?
Might homeopathic treatments work despite the fact that the underlying theory of how they would work is far from defensible? Well, maybe: but the proposed ban on homeopathic prescriptions, is, however, exactly based on the claim that there is no “top quality” evidence that homeopathic treatments are effective.
So if the underlying theories of homeopathy are pseudoscientific and there is no “top quality” evidence that homeopathic treatments are effective, what’s not to like about the proposed ban? Surely ineffective, pseudoscience-based “remedies” should not be prescribed on the NHS?
Let’s think, however, about what’s involved in evidence being rated as “top quality”. The relevant evidence comes from clinical trials. Such trials must, of course, involve a control group alongside the group of patients given the treatment under test. The trial should then have further methodological virtues in order for the evidence obtained from it to count as “top quality” – virtues such as not being too small and ensuring that patients and investigators are kept ‘blind’ to group-allocation.
The control in trials of homeopathic “remedies” is invariably a placebo treatment. All that a homeopathic treatment has to do, then, to garner “top quality” evidence is to outperform placebo in a well-performed trial – and that in effect surely means outperforming nothing!
But, although EBM-ers sometimes do equate giving a placebo with doing nothing, this is quite wrong: the evidence from both clinical trials and now neurological studies leaves the existence of placebo effects in no doubt. (Anyone still inclined to question this should consult Fabrizio Benedetti’s magisterial Placebo Effects, Oxford University Press, 2nd edition 2014.) Of course the effect’s range should not be overstated: it will not treat lung cancer, or ischemic heart disease. However there is an evidence-based positive placebo effect on such conditions as mild depression, IBS (irritable bowel syndrome) and on pain. And it is for the treatment of these sorts of conditions that homeopathic treatments are generally trialled. “No evidence of the effectiveness” of a treatment should not then be taken literally; it really means “no evidence of greater effectiveness than an (acknowledged) placebo”; and this is compatible with the treatment’s being effective at any rate for a range of conditions.
Moreover – the twist in the tale –, there is good evidence that a placebo-treatment in general has a greater effect if the person receiving it believes it not to be a placebo. There are clinical trials that support this, but the most impressive evidence for the role of expectations in outcomes comes from Benedetti’s “closed/open” studies. In the simplest scenario, a group of patients suffering, for example, from post-operative pain is divided into two: both groups receive exactly the same intravenous analgesic in exactly the same amount but the members of one (“closed”) group are not told when they are being given the analgesic (the morphine is delivered via an intravenous line at times of which the patients are unaware), while the members of the other (“open”) group are given the morphine via injection by a doctor. Pain relief is significantly greater in the latter group. (The best evidence for the placebo effect comes from investigations in which no placebo is involved!)
It seems quite likely that most of those prescribed homeopathy on the NHS are somewhat inclined to think it effective and that this belief will be bolstered by its being prescribed for them by a figure with authority. Hence the homeopathic substance may prove more effective (again for limited ranges of conditions and of patients), if prescribed by an NHS doctor rather than by a homeopath. Moreover the NHS doctor will be more likely than the homeopath to rule out a more serious underlying pathology before treating the “non-specific pain” or IBS. It seems that the vast majority of homeopathic prescriptions under the current NHS arrangements are for mild depression, IBS, non-specific pain and the like. Given that there is no “active” treatment that is unambiguously better for these complaints than a homeopathic placebo, the proposed ban would stop physicians from prescribing a treatment that they have good evidence to hold is effective. And of course homeopathic treatments are cheap and unlikely to have adverse side-effects!
The proposed ban seems initially like a “no-brainer” but maybe, when thought through, its rationale is not so clear-cut.
By John Worrall
John Worrall is a Professor in the Department of Philosophy, Logic and Scientific Method at LSE. As well as Evidence-based Medicine, he specialises in the philosophical issues raised by major theory-change in science; and is especially known for his work on structural realism. He is also the founder and lead guitarist of the Department’s house band, The Critique of Pure Rhythm.
Featured image credit: Jonathan Wilson / CC BY 2.0
One problem is that in ordinary practice (ie not trials) doctors are not allowed to prescribe placebos. When, therefore, they want to take advantage of the placebo effect, they must prescribe physiologically-active medicines with the risk that real side-effects will be produced. Allowing them to prescribe homoeopathic ‘medication’ might obviate this problem.
A premise that runs through this article is that there is no evidence to support homeopathy. That is of course incorrect. Here is just some of the evidence:
There other types of evidence, such as the fact that 100 million people in India depend entirely on homeopathy of ailments ranging from dengue fever to leprosy.. I’m sure all those people would be surprised to know they have been cured by placebo.
Having practiced homeopathy for over a quarter century I’ve learned that a homeopathy skeptic is simply someone who has never taken a well chosen remedy. It’s a simple as that. People learn with their bodies.
A large % of homeopathy supporters, like myself, turned to this form of treatment after suffering from disastrous health events that conventional medicine was unable to address or made worse.
Even the ardent UK critic, Edzard Ernst had to admit in an interview in 2003 that he treated his French wife with homeopathy since “we both grew up with it.” In another interview Ernst noted that he was “impressed” by the fact that in a homeopathic hospital where he was a young intern, patients treated with homeopathy were able to totally discontinue their use of prescription drugs. A literature search reveals that where homeopathic remedies have been either added to, as integrative treatment, or substituted for conventional drugs in clinics and hospital settings, this trend is well established.
Additionally, Professor E.Ernst, as a co-author of a research study regarding the benefit of homeopathy in the treatment of osteo and rheumatoid arthritis, concluded that the “evidence supports the use of homeopathic remedies over placebo in osteoarthritis & rheumatoid arthritis” http://www.ncbi.nlm.nih.gov/pubmed/15218409
First off, it is simply untrue that there is no “top quality” evidence that supports homeopathy. This is one of those talking points that permeates online media, thanks to skeptic propaganda, the purpose of which is to deliberately circulate disinformation about homeopathy. There are plenty of good trials, including RCTs and meta-analyses. To deny this is violate the principle of scientific objectivity. It should be noted that Dr. Hahnemann was one of the very first to introduce blindedness into his research. Provings were conducted on subjects who were unaware of the substances that they were taking. As such, Hahnemann was way ahead of his time.
Furthermore, the theories underlying homeopathy derive directly from the practice of homeopathy. They are attempts to explain the phenomena observed in clinical practice. In this sense, they are based upon empirical evidence. Professor Worrall admits to his bias when he calls homeopathic theory “fanciful – at least when judged from the standpoint of current science; and what other reasonable standpoint could there be?” As a matter of fact, there are a good number of additional reasonable standpoints. I assume that, as a philosopher of science, the Professor understands that science has evolved over the course of history. There is no reason to believe that we have somehow arrived at the apex of science, which will from henceforth cease to change. Homeopathy is a science that has already begun to change the way we think about a number of different phenomena.
I do agree with one point that Prof. Worrall makes, which is that EBM is “overly narrow and mechanistic,” and, I would add, both highly reductionistic and eggheadedly rationalistic to the point of being incapable of perceiving the obvious. This is the type of built-in tunnel vision that has allowed drugs to market that ultimately turn out to be quite dangerous. The same tunnel vision is very poorly suited to studying a holistic therapy such as homeopathy.
The Professor’s opinion here is clearly based upon a mixture of false information and his own philosophical beliefs that cause him to prejudge homeopathy as pseudoscientific. To write homeopathy off as placebo is further indication that he is making assumptions that do not correspond to the actual growing body of scientific evidence to the contrary.
Homeopathy works. It is practised by MD’s and hospitals around the world, particularly in Europe; taught in medical schools and universities and included by some Governments as part of their State medical system.
This would never happen and could never happen if it were not effective or pure placebo.
Would Professor Worrall be prepared to state that scientific understanding is absolutely complete and there is nothing left to learn about the possible capacity of water, in this instance, to receive, record, retain and release information? I doubt it. Just as quantum mechanics was controversial and horrifying to many noted scientists, including Einstein, so theories surrounding how Homeopathy might work are still in the realms of conjecture but that does not automatically make any of them wrong per se:
In addition, since Homeopathy is practised by many MD’s and hospitals around the world, particularly in Europe, it is very clear that not everyone agrees with Professor Worrall’ view and in fact one can assume they have done their own research and found Homeopathy credible, effective and more than pure placebo, or their actions would be fraudulent and most if not all of them would be sued and they are not. Ditto for medical schools and universities which teach it and Governments which include Homeopathy in their State medical systems.
And Professor Worrall is clearly unaware, no doubt the result of limited research that Homeopathic medicine has been found to demonstrate effect on cells, body tissue and plants and months after being taken which means patently it is not pure placebo.
In due respect, it would seem that a man of your stature would do his homework before pontificating on a subject he knows little. It seems embarrassing when ill-informed people assert that homeopathic medicines are “simply water.” Real scientists and academically-inclined individuals will benefit from reviewing the writings of Professor Martin Chaplin, a world renowned expert on water:
Unless you know something about WATER, saying that homeopathy is “just water” is without any meaning.
One important experience from homeopathic medicines is its use of “nanodoses” of various plants, mineral, or animal substances as medicines. Skeptics of homeopathy commonly assert that there is “nothing” in homeopathic medicines except water, and yet, such skeptics only “theorize” that such assertions are true and have never proven this in controlled scientific studies. In comparison, research published in the American Chemistry Society’s leading scientific journal, called “Langmuir,” has confirmed in controlled studies that “nanodoses” of homeopathic medicines remain in solution even after they are diluted 1:100 six times, 30 times, or even 200 times (Chikramane, Kalita, Suresh, et al, 2012).
Skeptics of homeopathy then assert that these nanodoses cannot possibly have any physiological effect on the human body, and yet, such skeptics embarrassingly enough prove their own ignorance of normal human physiology because many of our body’s hormones and cell-signal systems are known to operate at similar nanodoses found in homeopathic medicines (Eskinazi, 1999). Are skeptics of homeopathy actually asserting that our hormones act as placebo? I sincerely hope not!
Ultimately, high quality research showing the efficacy of homeopathic medicines have been published in many of the most respected medical journals in the world, including The Lancet, BMJ (British Medical Journal), Chest (the publication of the American College of Chest Physicians), Rheumatology (the publication of the British Society for Rheumatology), Pediatrics (publication of the American Academy of Pediatrics), Cancer (journal of the American Cancer Society), Journal of Clinical Oncology, Pediatrics Infectious Disease Journal (publication of the European Society of Pediatric Infectious Diseases), European Journal of Pediatrics (publication of the Swiss Society of Pediatrics and the Belgium Society of Pediatrics), and numerous others (Ullman, 2014).
Why do you think that 95% of French pediatricians, dermatologists, and general family practitioners use homeopathic medicines? Are you so arrogant to condemn them all for using placebos? (http://www.ncbi.nlm.nih.gov/pubmed/25921648)
And if so, how can you explain that homeopathy gained its popularity in the USA and Europe due to its amazing successes in treating infectious diseases of that day and age, including cholera, typhoid, yellow fever, scarlet fever, and many others? This is historical FACT, not any theory.
Chikramane PS, Kalita D, Suresh AK, Kane SG, Bellare JR. Why Extreme Dilutions Reach Non zero Asymptotes: A Nanoparticulate Hypothesis Based on Froth Flotation. Langmuir. 2012 Nov http://www.ncbi.nlm.nih.gov/pubmed/23083226
Eskinazi, D., Homeopathy Re-revisited: Is Homeopathy Compatible with Biomedical Observations? Archives in Internal Medicine, 159, Sept 27, 1999:1981-7. http://www.ncbi.nlm.nih.gov/pubmed/10510983
Ullman, Dana. Dysfunction at Wikipedia on Homeopathic Medicine. http://www.huffingtonpost.com/dana-ullman/dysfunction-at-wikipedia-_b_5924226.html (Rather than list the reference for each of the studies listed in this paragraph, this article provides such references.)
I see that a number of homeopathy apologists have posted here and most of them, if not all, are US based. The UK health system is very different from the US, as are the legislation and regulations that cover homeopathic medicines.
In the UK, in order for a homeopathic medicine to be put on the market, it must be registered with the MHRA. There are purported thousands of different homeopathic medicines but not that many that registered. The unregistered ones are treated as unlicensed medicines. You will only find a handful of registered ones in most high street dispensing pharmacies. Whilst there are exemptions that allow for the supply of unregistered homeopathic medicines, effectively they can only be supplied by the manufacturer.
All NHS organisations should have a policy in place regarding prescription of unlicensed medicines, which would by de facto cover unregistered homeopathic medicines.
Use of homeopathy is in decline in the NHS. There seems little point in an outright prescription ban when it is slowly shrinking away to nothing. It’s a symbolic act.
The length of a homeopathic consultation varies – can be as long as an hour. This is far longer than any NHS GP consultation.
Great article and beautifully written. The only (small) thing to add is that Professor Worrall claims that ‘ there is good evidence that a placebo-treatment in general has a greater effect if the person receiving it believes it not to be a placebo’. In support of this claim, he cites open versus hidden trials. Open versus hidden treatment is not quite the same as deceptive versus non-deceptive placebo, see here for evidence: https://www.ncbi.nlm.nih.gov/pubmed/28452193.
This post is a helpful overview of the particular topic and very actionable. Interesting approach!