I have often asked myself whether it is right/necessary to scientifically test things which are entirely implausible. Should we, for instance test the effectiveness of treatments which have a very low prior probability of generating a positive effect such as paranormal healing, homeopathy or Bach flower remedies? If you believe in the principles of evidence-based medicine you might focus on the clinical evidence and see biological plausibility as secondary. If you are a basic scientist, you are likely to do the reverse.
A recent article addressed this issue. The author points out that evaluating the absurd is absurd. Specifically, he noted that the empirical evaluation of a therapy would normally assume a plausible rationale regarding the mechanism of action. However, examination of the historical background and underlying principles for reflexology, iridology, acupuncture, auricular acupuncture, and some herbal medicines, reveals a rationale founded on the principle of analogical correspondences, which is a common basis for magical thinking and pseudoscientific beliefs such as astrology and chiromancy. Where this is the case, it is suggested that subjecting these therapies to empirical evaluation may be tantamount to evaluating the absurd.
This makes a lot of sense – but is it really entirely true? Are there no legitimate reasons at all for testing alternative treatments that lack biological plausibility? Ten or twenty years ago, I would have disagreed with the notion that plausibility is an essential prerequisite for scientific testing; today, I have changed my mind a little, but not as much as to agree completely with the assumption. In other words, I still see more than one good reason why evaluating the absurd might be reasonable or even advisable.
- Using plausibility as the only arbiter of scientific ‘evaluability’, assumes that we understand everything about plausibility there is to know. Yet it might just be possible that we mis-categorise something as implausible simply because we are not yet fully aware of all the facts.
- Declaring something as plausible and another thing as implausible are not hard and fast verdicts but judgements which, at least to some degree, are subjective. Sceptics find the axioms of homeopathy utterly implausible, for instance – but ask a homeopath, and you will hear all sorts of explanations which, at least to them, sound plausible.
- If an implausible alternative treatment is in wide-spread use, we arguably have a responsibility to test it scientifically in order to demonstrate the truth about it (to those proponents of that therapy who are willing to accept that rigorous science can find the truth). If we fail to do this, it will be the enthusiasts of that therapy who conduct less than rigorous science and produce false positive results. In turn, this will give the impression that the treatment is effective and mislead consumers, politicians, journalists etc. Seen from this perspective, it might even be unethical to not do the science.
So, I am in two minds about this (which might be a reflection of the fact that, during different periods of my life, I have been a clinician, a basic scientist and a clinical researcher). I realise that plausibility and prior probability are important – much more so than I appreciated years ago. But I think they should not be the only criteria. The clinical evidence should not be pushed aside completely.
I’d be interested to learn your views on this tricky issue.
Homeopathy is a deeply puzzling subject for many observers. Perhaps it gets a little easier to understand, if we consider the three main perspectives on homeopathy. For the purpose of this post, I take the liberty of exaggerating, almost caricaturizing, these perspectives in order to contrast them as clearly as possible.
THE SCEPTICS’ PERSPECTIVE
Sceptics take a brief look at the two main assumptions which underpin homeopathy (like cures like and potentiation/dilution/water memory) and henceforward are convinced that homeopathic remedies are pure placebos. Homeopathy flies in the face of science; if homeopathy is right, several laws of nature must be wrong, they love to point out. As this is most unlikely, they reject homeopathy outright, usually even without looking in any detail at what homeopaths consider to be evidence in support of their trade. If sceptics are forced to consider a positive study of homeopathy, they know before they have seen it that its results are wrong – due to an error caused by chance, faulty study design or fabrication. The sceptics’ conclusion on homeopathy: it is a placebo-therapy, no doubt about it; and further investment into research is a waste of scarce resources which must be stopped.
THE BELIEVERS’ PERSPECTIVE
The believers in homeopathy know from experience that homeopathy works. They therefore feel that they have no choice but to reject almost every word the sceptics might tell them. They cling on to the gospel of Hahnemann and elaborate on the modern but vague theories that might support the theoretical assumptions of homeopathy. They point to positive clinical trials and outcome studies, to 200 years of experience, and to the endorsement of homeopathy by VIPs. When confronted with the weaknesses of their arguments, they find even weaker ones, such as ‘much of conventional medicine is also not based on good evidence, and the mechanism of action of many mainstream drugs is also not fully understood’. Alternatively, they employ the phoniest argument of them all: ‘even if it works via a placebo effect, it still helps patients and therefore is a useful therapy’. When even this fails, they tend to resort to ad hominem attacks against their opponents. The believers’ conclusion on homeopathy: it is unquestionably a valuable type of therapy regardless of what anyone else might say; research is merely needed to confirm their belief.
THE PERSPECTIVE OF THE ADVOCATES OF EVIDENCE-BASED MEDICINE (EBM)
The perspective of EBM-advocates is pragmatic; they simply say: “show me the evidence!” If the majority of the most reliable clinical trials of homeopathic remedies (or anything else) suggests an effect beyond placebo, they conclude that they are effective. If that is not the case, they doubt the effectiveness. If the evidence is highly contradictory or incomplete, they are likely to advocate more rigorous research. Advocates of EBM are usually not all that concerned by the lack of plausibility of the interventions they evaluate. If it works, it works, they think – and if a plausible mechanism is currently not available, it might be found in due course. The advocates of EBM have no preconceived ideas about homeopathy. Their conclusion on homeopathy goes exactly where the available best evidence leads them.
The arguments and counter-arguments originating from the various perspectives would surely continue for another 200 years – unless, of course, two of the three perspectives merge and arrive at the same or very similar conclusions. And this is precisely what has now happened. As I have pointed out in a recent post, the most thorough and independent evaluation of homeopathy according to rigorous EBM-standards has concluded that “the evidence from research in humans does not show that homeopathy is effective for treating the range of health conditions considered.”
In other words, two of the three principal perspectives have now drawn conclusions which are virtually identical: there is a consensus between the EBM-advocates and the sceptics. This isolates the believers and renders their position no longer tenable. If we furthermore consider that the believers are heavily burdened with obvious conflicts of interest, while the other two groups are by definition much more independent and objective, it appears more and more as though homeopathy is fast degenerating into a cult characterised by the unquestioning commitment and unconditional submission of its members who are too heavily brain-washed to realize that their fervour has isolated them from the rational sections of society. And a cult is hardly what we need in heath care, I should think.
It seems to me therefore that these intriguing developments might finally end the error that homeopathy represented for nearly 200 years.
Progress at last?
Advocates of alternative medicine are incredibly fond of supporting their claims with anecdotes, or ‘case-reports’ as they are officially called. There is no question, case-reports can be informative and important, but we need to be aware of their limitations.
A recent case-report from the US might illustrated this nicely. It described a 65-year-old male patient who had had MS for 20 years when he decided to get treated with Chinese scalp acupuncture. The motor area, sensory area, foot motor and sensory area, balance area, hearing and dizziness area, and tremor area were stimulated once a week for 10 weeks, then once a month for 6 further sessions.
After the 16 treatments, the patient showed remarkable improvements. He was able to stand and walk without any problems. The numbness and tingling in his limbs did not bother him anymore. He had more energy and had not experienced incontinence of urine or dizziness after the first treatment. He was able to return to work full time. Now the patient has been in remission for 26 months.
The authors of this case-report conclude that Chinese scalp acupuncture can be a very effective treatment for patients with MS. Chinese scalp acupuncture holds the potential to expand treatment options for MS in both conventional and complementary or integrative therapies. It can not only relieve symptoms, increase the patient’s quality of life, and slow and reverse the progression of physical disability but also reduce the number of relapses and help patients.
There is absolutely nothing wrong with case-reports; on the contrary, they can provide extremely valuable pointers for further research. If they relate to adverse effects, they can give us crucial information about the risks associated with treatments. Nobody would ever argue that case-reports are useless, and that is why most medical journals regularly publish such papers. But they are valuable only, if one is aware of their limitations. Medicine finally started to make swift progress, ~150 years ago, when we gave up attributing undue importance to anecdotes, began to doubt established wisdom and started testing it scientifically.
Conclusions such as the ones drawn above are not just odd, they are misleading to the point of being dangerous. A reasonable conclusion might have been that this case of a MS-patient is interesting and should be followed-up through further observations. If these then seem to confirm the positive outcome, one might consider conducting a clinical trial. If this study proves to yield encouraging findings, one might eventually draw the conclusions which the present authors drew from their single case.
To jump at conclusions in the way the authors did, is neither justified nor responsible. It is unjustified because case-reports never lend themselves to such generalisations. And it is irresponsible because desperate patients, who often fail to understand the limitations of case-reports and tend to believe things that have been published in medical journals, might act on these words. This, in turn, would raise false hopes or might even lead to patients forfeiting those treatments that are evidence-based.
It is high time, I think, that proponents of alternative medicine give up their love-affair with anecdotes and join the rest of the health care professions in the 21st century.
Nobody really likes criticism, I suppose. Yet everyone with a functional brain agrees that criticism is a precondition to making progress. So most of us do listen to it, introspect and try to learn a lesson.
Not so in alternative medicine! The last post by Preston Long was a summary of constructive criticism of his own profession; it brought that message home to me much clearer than previous discussions on this blog (probably because it did not directly concern me) and, after some reflection, I realised that apologists of alternative medicine have developed five distinct strategies to avoid progress that otherwise might develop from criticism (alright, these strategies do exist in other fields too, but I think that many of the comments on this blog demonstrate that they are particularly evident in alternative medicine).
We could also call this method ‘The Prince of Wales Technique of Avoiding Progress’ because HRH is famous for making statements ‘ex cathedra’ without ever defending them or facing his critics or allowing others to directly challenge him. When he advocated the Gerson diet for cancer, for instance, Prof Baum challenged him in an open letter asking him to use his influence more wisely. Like with all other criticism directed to him, he decided to ignore it. This strategy is a safe bet for stalling progress and it has the added advantage that it does not require anything other than ignorance.
As it requires some basic understanding of the issues at hand, this method is a little more demanding. You need to look closely at the criticism and subsequently shoot holes in it. If you cannot find any, invent some. For instance, you might state that your critic misquoted the evidence. Very few people will bother to read up the original data, and you are likely to get away even with fairly obvious lies. To beef your response up a bit, pretend that there is plenty of good evidence demonstrating exactly the opposite of what your critic has said. If asked to provide actual references or sources for your claims, don’t listen. An extreme example of the bluff-method is to sue your critic for libel – but be careful, this can backfire in a major way!
A very popular method is to claim that the critic is not actually competent to criticise. The discussion of Long’s post demonstrated that technique in a classic fashion. His detractors argued that he was a failed chiropractor who had an axe to grind and thus had no right to criticise chiropractic (“Preston H Long you are a disgrace to the chiropractic profession…take off your chiropractic hat, you dont deserve to wear it. YOU sir are a shame and a folly!!”). Of course, you need to be a bit simple in order to agree with this type of logic, but lots of people seem to be just that!
Even more popular is the blame-game. It involves arguing that, ok not all is rosy on your side of the fence, but the other side is so, so much worse. Before they dare to challenge you, they should look at their own mess; and while it is not sorted, they must simply shut up. For instance, if the criticism is that chiropractors have put hundreds of their patients into wheelchairs with their neck-manipulations, you must point out that doctors with their nasty drugs are much, much worse (“Long discounts the multitudes that chiropractic has… saved from dangerous drugs and surgery. As far as risks of injury from seeing a chiropractor vs. medicine, all one needs to do is compare malpractice insurance rates to see that insurance carriers rate medicine as an exponentially more dangerous undertaking”). Few people will realise that this is a fallacy and that the risks of any therapy must be seen in relation to its potential benefits.
When criticised, you are understandably annoyed; most people will therefore forgive you calling your critic names which are not normally used in polite circles (“who is this idiot, who wouldnt know the first thing about chiropractic”). Ad hominem attacks are the last resort of apologists of alternative medicine which emerges with depressing regularity when they have run out of rational arguments; they are signs of victories of reason over unreason. In the case of those chiropractors who were unable to stomach Long’s critique, the insults were coming thick and fast. The reason for only very few being visible is quite simple: I often delete the worst excesses of such primitive reactions.
It is time, I think, to call an end to this series of articles on ‘drowning in a sea of misinformation’. Not that I have covered every contributor to and aspect of it. On the contrary, I could have carried on for another couple of weeks writing a post every day as I did during the last 15 days. But it was getting a bit boring – at least for me. So, for the last post, I have decided to briefly discuss politicians. In my view, they are crucially important in this context, as they create the general atmosphere and framework in which all the other mis-informers can thrive.
Peter Hain (Labour) is a campaigner for homeopathy and wants to see it widely used on the NHS. He was quoted as saying: “I first came to know about homeopathy through my son who as a baby suffered from eczema. He had it a couple of years but with conventional treatment the eczema was getting progressively worse and at the age of four he also developed asthma. We turned to homeopathy out of desperation and were stunned with the positive results. Since then I have used homeopathy for a wide variety of illnesses, but I rely on arnica as it’s excellent for treating the everyday bruises and shocks to the system we face. My view is that homeopathy and conventional medicines must remain side by side under the NHS to offer the best to patients”
Politicians who put anecdote before evidence do worry me quite a bit, I have to admit; by doing this, they provide us with strong evidence that they would be wise to keep their mouth shut when it comes to matters of science and medicine. But Hain is in good company: Jeremy Hunt (conservative), the current Secretary for Health, signed the following Early Day Motion in 2007: That this House welcomes the positive contribution made to the health of the nation by the NHS homeopathic hospitals; notes that some six million people use complementary treatments each year; believes that complementary medicine has the potential to offer clinically-effective and cost-effective solutions to common health problems faced by NHS patients, including chronic difficult to treat conditions such as musculoskeletal and other chronic pain, eczema, depression, anxiety and insomnia, allergy, chronic fatigue and irritable bowel syndrome; expresses concern that NHS cuts are threatening the future of these hospitals; and calls on the Government actively to support these valuable national assets.
The wording here is remarkable, I think: “…believes that complementary medicine has the potential to offer clinically-effective and cost-effective solutions to common health problems faced by NHS patients…” What is this supposed to mean? Health politics based on believe??? What it, in fact, implies is that there is merely belief but no evidence. Bravo! This looks like an own-goal to me.
And there are many, many more politicians who seem to prefer belief over evidence – not just in the UK but in virtually every country; our US friends would probably want me to mention Senator Tom Harkin who is responsible for spending billions of tax-payers’ dollars on researching implausible concepts with flawed studies. To make things worse, it is not just individual politicians who promote woo, as far as I can see, most political parties have a group of members promoting pseudo-science.
But why? Why do so many politicians misinform their voters about the values of unproven and disproven treatments? And I do not mean those members of parliament who nobody seems to be able to take seriously, like David Tredenick; I mean otherwise respectable politicians with real influence. Should they not be the first to insist on reliable evidence? Do they not have a mandate and an ethical/moral obligation to do so?
Call me cynical, but I have come to the conclusion that the answer is actually quite simple. Politicians need to be (re-)elected, and therefore they have to run with whatever subject is popular – and, like it or not, alternative medicine is popular. Politicians rarely take a reasonably long view on health care (in fact, very few understand the first thing about science or medicine); their perspective has exactly the same length as the current legislative period. They usually do not even attach much importance to alternative medicine; after all, it only amounts to a tiny fraction of the total health care budget.
Tony Blair (Labour) is as good an example as any other politician; in relation to homeopathy, he is quoted saying: I think that most people today have a rational view about science and my advice to the scientific community would be fight the battles you need to fight. I wouldn’t bother fighting a great battle over homeopathy – there are people who use it, people who don’t use it, it is not going to determine the future of the world, frankly. What will determine the future of the world however, is the scientific community explaining for example the science of genetics and how it develops, or the issue to do with climate change and so on.
Sounds reasonable? Almost, but not quite. Firstly, if people employ homeopathy to protect themselves from infectious diseases like malaria, typhus, TB, AIDS etc., or if people believe those charlatans who promote it as an effective cure for life-threatening conditions, we do have a serious public health issue at hand. Secondly, why should the vast majority of health care professionals bend over backwards to do their very best implementing the concepts of EBM, if homeopathy is being given a free ride to continue existing in a virtual universe of belief-based medicine? Thirdly, how on earth can scientists possibly explain “the science of genetics and how it develops, or the issue to do with climate change”, if they lack the skill, courage, power or honesty to adequately respond to harmful quackery masquerading as medicine?
It is not difficult to criticise politicians but what might be the way forward and out of this mess? Because of the central role they play in all this, I think that it would be important that those politicians who take up posts in science-based areas be adequately educated and trained in science. I know this may sound naïve, but I think it would be an essential step towards avoiding politicians regularly making fools of themselves, misinforming the public and misguiding important decisions which might affect all of us.
Can one design a clinical study in such a way that it looks highly scientific but, at the same time, has zero chances of generating a finding that the investigators do not want? In other words, can one create false positive findings at will and get away with it? I think it is possible; what is more, I believe that, in alternative medicine, this sort of thing happens all the time. Let me show you how it is done; four main points usually suffice:
- The first rule is that it ought to be an RCT, if not, critics will say the result was due to selection bias. Only RCTs have the reputation of being ‘top notch’.
- Once we are clear about this design feature, we need to define the patient population. Here the trick is to select individuals with an illness that cannot be quantified objectively. Depression, stress, fatigue…the choice is vast. The aim must be to employ an outcome measure that is well-accepted, validated etc. but which nevertheless is entirely subjective.
- Now we need to consider the treatment to be “tested” in our study. Obviously we take the one we are fond of and want to “prove”. It helps tremendously, if this intervention has an exotic name and involves some exotic activity; this raises our patients’ expectations which will affect the result. And it is important that the treatment is a pleasant experience; patients must like it. Finally it should involve not just one but several sessions in which the patient can be persuaded that our treatment is the best thing since sliced bread – even if, in fact, it is entirely bogus.
- We also need to make sure that, for our particular therapy, no universally accepted placebo exists which would allow patient-blinding. That would be fairly disastrous. And we certainly do not want to be innovative and create such a placebo either; we just pretend that controlling for placebo-effects is impossible or undesirable. By far the best solution would be to give the control group no treatment at all. Like this, they are bound to be disappointed for missing out a pleasant experience which, in turn, will contribute to unfavourable outcomes in the control group. This little trick will, of course, make the results in the experimental group look even better.
That’s about it! No matter how ineffective our treatment is, there is no conceivable way our study can generate a negative result; we are in the pink!
Now we only need to run the trial and publish the positive results. It might be advisable to recruit several co-authors for the publication – that looks more serious and is not too difficult: people are only too keen to prolong their publication-list. And we might want to publish our study in one of the many CAM-journals that are not too critical, as long as the result is positive.
Once our article is in print, we can legitimately claim that our bogus treatment is evidence-based. With a bit of luck, other research groups will proceed in the same way and soon we will have not just one but several positive studies. If not, we need to do two or three more trials along the same lines. The aim is to eventually do a meta-analysis that yields a convincingly positive verdict on our phony intervention.
You might think that I am exaggerating beyond measure. Perhaps a bit, I admit, but I am not all that far from the truth, believe me. You want proof? What about this one?
Researchers from the Charite in Berlin just published an RCT to investigate the effectiveness of a mindful walking program in patients with high levels of perceived psychological distress.
To prevent allegations of exaggeration, selective reporting, spin etc. I take the liberty of reproducing the abstract of this study unaltered:
Participants aged between 18 and 65 years with moderate to high levels of perceived psychological distress were randomized to 8 sessions of mindful walking in 4 weeks (each 40 minutes walking, 10 minutes mindful walking, 10 minutes discussion) or to no study intervention (waiting group). Primary outcome parameter was the difference to baseline on Cohen’s Perceived Stress Scale (CPSS) after 4 weeks between intervention and control.
Seventy-four participants were randomized in the study; 36 (32 female, 52.3 ± 8.6 years) were allocated to the intervention and 38 (35 female, 49.5 ± 8.8 years) to the control group. Adjusted CPSS differences after 4 weeks were -8.8 [95% CI: -10.8; -6.8] (mean 24.2 [22.2; 26.2]) in the intervention group and -1.0 [-2.9; 0.9] (mean 32.0 [30.1; 33.9]) in the control group, resulting in a highly significant group difference (P < 0.001).
Conclusion. Patients participating in a mindful walking program showed reduced psychological stress symptoms and improved quality of life compared to no study intervention. Further studies should include an active treatment group and a long-term follow-up
This whole thing could just be a bit of innocent fun, but I am afraid it is neither innocent nor fun, it is, in fact, quite serious. If we accept manipulated trials as evidence, we do a disservice to science, medicine and, most importantly, to patients. If the result of a trial is knowable before the study has even started, it is unethical to run the study. If the trial is not a true test but a simple promotional exercise, research degenerates into a farcical pseudo-science. If we abuse our patients’ willingness to participate in research, we jeopardise more serious investigations for the benefit of us all. If we misuse the scarce funds available for research, we will not have the money to conduct much needed investigations. If we tarnish the reputation of clinical research, we hinder progress.
If one spends a lot of time, as I presently do, sorting out old files, books, journals etc., one is bound to come across plenty of weird and unusual things. I for one, am slow at making progress with this task, mainly because I often start reading the material that is in front of me. It was one of those occasions that I had begun studying a book written by one of the more fanatic proponent of alternative medicine and stumbled over the term THE PROOF OF EXPERIENCE. It made me think, and I began to realise that the notion behind these four words is quite characteristic of the field of alternative health care.
When I studied medicine, in the 1970s, we were told by our peers what to do, which treatments worked for which conditions and why. They had all the experience and we, by definition, had none. Experience seemed synonymous with proof. Nobody dared to doubt the word of ‘the boss’. We were educated, I now realise, in the age of EMINENCE-BASED MEDICINE.
All of this gradually changed when the concepts of EVIDENCE-BASED MEDICINE became appreciated and generally adopted by responsible health care professionals. If now the woman or man on top of the medical ‘pecking order’ claims something that is doubtful in view of the published evidence, it is possible (sometimes even desirable) to say so – no matter how junior the doubter happened to be. As a result, medicine has thus changed for ever: progress is no longer made funeral by funeral [of the bosses] but new evidence is much more swiftly translated into clinical practice.
Don’t get me wrong, EVIDENCE-BASED MEDICINE does not does not imply disrespect EXPERIENCE; it merely takes it for what it is. And when EVIDENCE and EXPERIENCE fail to agree with each other, we have to take a deep breath, think hard and try to do something about it. Depending on the specific situation, this might involve further study or at least an acknowledgement of a degree of uncertainty. The tension between EXPERIENCE and EVIDENCE often is the impetus for making progress. The winner in this often complex story is the patient: she will receive a therapy which, according to the best available EVIDENCE and careful consideration of the EXPERIENCE, is best for her.
NOT SO IN ALTERNATIVE MEDICINE!!! Here EXPERIENCE still trumps EVIDENCE any time, and there is no need for acknowledging uncertainty: EXPERIENCE = proof!!!
In case you think I am exaggerating, I recommend thumbing through a few books on the subject. As I already stated, I have done this quite a bit in recent months, and I can assure you that there is very little evidence in these volumes to suggest that data, research, science, etc.. matter a hoot. No critical thinking is required, as long as we have EXPERIENCE on our side!
‘THE PROOF OF EXPERIENCE’ is still a motto that seems to be everywhere in alternative medicine. In many ways, it seems to me, this motto symbolises much of what is wrong with alternative medicine and the mind-set of its proponents. Often, the EXPERIENCE is in sharp contrast to the EVIDENCE. But this little detail does not seem to irritate anyone. Apologists of alternative medicine stubbornly ignore such contradictions. In the rare case where they do comment at all, the gist of their response normally is that EXPERIENCE is much more relevant than EVIDENCE. After all, EXPERIENCE is based on hundreds of years and thousands of ‘real-life’ cases, while EVIDENCE is artificial and based on just a few patients.
As far as I can see, nobody in alternative medicine pays more than a lip service to the fact that EXPERIENCE can be [and often is] grossly misleading. Little or no acknowledgement exists of the fact that, in clinical routine, there are simply far too many factors that interfere with our memories, impressions, observations and conclusions. If a patient gets better after receiving a therapy, she might have improved for a dozen reasons which are unrelated to the treatment per se. And if a patient does not get better, she might not come back at all, and the practitioner’s memory will therefore fail register such events as therapeutic failures. Whatever EXPERIENCE is, in health care, it rarely constitutes proof!
The notion of THE PROOF OF EXPERIENCE, it thus turns out, is little more than self-serving, wishful thinking which characterises the backward attitude that seems to be so remarkably prevalent in alternative medicine. No tension between EXPERIENCE and EVIDENCE is noticeable because the EVIDENCE is being ignored; as a result, there is no progress. The looser is, of course, the patient: she will receive a treatment based on criteria which are less than reliable.
Isn’t it time to burry the fallacy of THE PROOF OF EXPERIENCE once and for all?