Talking to my GP father about homeopathy #2
Posted on March 23rd, 2010 in Skepticism | 3 Comments »
TOM
Let’s start by enlarging the list of things we both agree on.
I agree that placebo pills cause no direct harm whereas absolutely any active chemical introduced into the body has at least the potential for harm, even those which have long been associated with health and well-being; there is, for example, some evidence that routinely taking vitamin supplements when not indicated may have negative health outcomes.
I also agree that homeopathy and other alternative modalities make some people feel better but regret that the only way to safeguard the efficacy of the intervention is to mislead patients as to what is going on. It is important that the patient believes that the pill, needle, shamanic ritual or whatever will be efficacious. When prescribing even (or especially) a very risky treatment like radiotherapy, a physician can explain the potential costs and benefits, based on a large body of evidence, in order that the patient can make an informed choice. Prescribing placebo treatments as if they are effective removes that informed choice, but telling the patient “this won’t work” is a self-fulfilling prophecy, so homeopaths – whether or not they are themselves deluded – are deceiving their patients.
Of course, if patients want it and are made to feel better, why should we worry about removing informed choice? I do have an answer to this question, but I don’t want to get ahead of myself. Let me finish responding to your points first.
You write that you think that homeopathy is an appropriate use of public funds to treat chronic conditions for which no effective evidence-based treatment exists, and it may be that the London Homeopathic Hospital does restrict itself to interventions in those cases. It may also be that all of the Homeopaths working there are medically qualified (I wasn’t aware of this – do you have a reference?).
But it is not true, despite the name, that within the tranquil environment of the LHH, homeopathy is the only evidence-free service available. A quick look at their website reveals that they are also happy to provide Reiki, Acupuncture, Reflexology and Iscador – a new one on me – which we learn is “a preparation of mistletoe, which enhances immune system responses.” Bearing in mind that this is on a page titled Complementary Cancer Care Programme, doesn’t this worry you at all? Do you really want your patients believing that mistletoe will cure their cancer? Who benefits from sustaining this belief, except those who have “Iscador” to sell?
Only one passage in your very thoughtful email stood out as something I would really take issue with – this one: “Every form of medical practice has its own philosophy, including evidence based medicine, which, by the way is not always as reproducible in an ordinary community setting as it is under strict experimental conditions. Even EBM in most cases only offers a probability of a cure or improvement: a significant proportion of those treated will not benefit at all. Some will be harmed.” Let me begin with your last point. Yes, every active treatment has a risk, but as I’ve said EBM enables patients and physicians to make informed choices. It is possible to do great harm with the best intentions, which is way we must hold evidence in such high regard. Are you familiar with the on-going libel case which the British Chiropractic Association recently brought against the journalist Simon Singh? This case illustrates one of my chief reasons to want to see homeopathy and other sham treatments no longer flattered by government support.
You warn me that lab trials are not always replicated in the real world. But my definition of “evidence” is not so narrow as to only include clinical trials (although I still regard a large, prospective, double-blind, randomised trial as the gold standard for determining whether and to what extent a given intervention will be effective). We can certainly obtain data from retrospective analyses, and from seeing what actually happens in the real world. Sometimes these results are surprising, but EBM means we can’t ignore results which sound wrong to us or which go against long-cherished notions.
For example, the United States Preventative Services Task Force recently altered its recommendations regarding breast cancer screening. In their report was the rather surprising and controversial finding that self-examination appears to have no effect whatsoever on breast cancer death rates, but that it can create a lot of unnecessary fear and alarm. The emphasis (at least in the States) is now on breast awareness – has anything in your breasts changed recently? – rather than teaching women to perform rigorous and regular self-examinations. Many people object to this advice on the basis that they have a belief that breast self-exams are important, or that they have a story about someone who found a lump during such an exam, and whose life may have been saved thanks to the operation which swiftly followed. This doesn’t alter the evidence which is that such exams make no difference to health outcomes, and we take lives in our hands if we allow our preconceptions and biases to defeat the evidence.
Where we really part company is when you describe different forms of medical practice as having their own philosophies. It sounds to me as if you are claiming that each of these philosophies is equally good, and the only real difference is in the philosophical starting point, EBM being no better and no worse than homeopathy. While that might be a useful diplomatic position to take, I simply can’t accept it, any more than I would accept Apartheid (or any one of a number of other atrocities) as a mere difference in political philosophy.
While it is true that there is a bewildering array of supposedly therapeutic modalities available, they all slot cleanly into one of two categories – based on evidence or not based on evidence. Anything not based on evidence is based to some extent on subjectivity and personal choice. A practitioner who accepts Reiki but rejects Iridology has no objective basis for making this choice. They simply prefer Reiki and allow confirmation bias to do the rest.
When the system is working (and god knows it doesn’t always) evidence-based medicine prevents even the most enthusiastic champion of a particular intervention from being able to claim that it works when it doesn’t. We know that Dimebon is ineffective for treating Alzheimer’s and so it will not be prescribed. We know that mistletoe will not cure cancer, but at the Royal London Homeopathic Hospital, they will apparently provide it to anyone who asks, and at the taxpayer’s expense.
This means that proponents of non-evidence based modalities have no choice but to duck the issue, or misleadingly cherry-pick from the data in order to create a false picture – which is exactly what the select committee experienced when it asked notable homeopaths to give evidence. Who benefits from this corruption of the scientific method? Isn’t this exactly the “denying the validity of science itself” which you hoped wouldn’t happen? Why does homeopathy get a pass? Because it does no harm? I’m not so sure that’s true.
You began by saying that you wanted to include in our discussion the whole context of treatment, and here again I agree enthusiastically. So, while we both know that a sugar pill in itself is guaranteed harmless, we also know that we are talking about a complicated cultural phenomenon which is not limited to a person taking a pill, and therefore nor is homeopathy’s reach confined to people suffering from chronic back pain. Nor is it always the case that homeopaths advise people who need conventional treatment to go and get it. In 2006, a survey performed by Sense about Science which was followed up by Newsnight found that every high street homeopath visited by a researcher about to travel to a malaria-infested country was given useless homeopathic quinine and none were told to visit a GP or a travel clinic or even to buy a mosquito net.
How are “responsible” homeopaths supposed to respond to this? The Royal Homeopathic Hospital did its best to smack down this irresponsible behaviour, but what are they really saying? “We all know the sugar pills don’t really work, so don’t for goodness sake go giving them to someone who actually needs medicine.” What would the True Believers make of that!? By beginning from a position which isn’t supported by evidence, “responsible” homeopaths are now in an impossible bind. They either have to defend the magic to the hilt, or admit that it’s all a load of imaginative nonsense. Not surprisingly, they hem and haw and waffle and evade, they dissemble in front of parliamentary select committees, and essentially they let the harm continue, such as in the horrifying case of the Australian couple who attempted to treat their baby daughter’s eczema with homeopathy until eventually she died after months of excruciating pain (they are now in prison).
So even if we are happy to divide quackery into good (prescribed by responsible physicians in tandem with evidence-based treatments where appropriate) and bad (prescribed willy-nilly by people with little or no medical training, and cheerfully offered as a substitute for evidence-based treatments, or non-medicalised interventions) – the question must still be asked can you have one without the other? This line of argument will eventually bring us back to vaccines, but I feel I should stop here, having written quite a lot already, and get another response from you.
JOHN
Can we aim for something a little more concise? I don’t have time for a discussion in this depth!
I am very pleased that you are taking such an interest in medicine and medical ethics. I note that you are a very much a postitivist in your approach and have no time for post-modernist ideas of different beliefs having equal validity! Well I don’t know that I have in extreme cases where it is clear that science has the best solution (e.g. antibiotic for pneumonia or angioplasty for blocked artery).
However, there are many grey areas where all is not as certain as one would like. As I have already mentioned, the much venerated ‘gold standard’ trial doesn’t simply distinguish effective from ineffective interventions. When the effect is really clear you dont need a trial. What we usually get is a statistical result showing that the probability of an effect is greater than could be due to chance alone. This means that some patients will do well but others won’t. The NNT (number needed to treat) may be 4 or 5 for a good drug or 10 or more for many others. So we can’t promise our patients that even a gold standard treatment will do them any good (or no harm). It’s a game of roulette. No one can tell what will happen to any individual.
It is unfortunately not the case that everything slots neatly into two categories, evidence-based or not. Evidence can be strong or weak. Evidence is continually being modified or even contradicted. It doesn’t apply to all individuals. So I tell my patients who ask me if complementary treatments are any good, that some patients find them helpful but others don’t. Same difference.
I agree that it would be dishonest to say that ‘a sugar pill’ will have a biochemical effect. But you can say that, some practioners believe that the way this pill was made can make a difference to the ability of some people to cope with an illness that conventional medicine has not been able to help very much.
I agree, of course, that no one should make false claims about these remedies. The information for cancer patients from the Homeopathic Hospital seems to me to make it very clear that these treatments are to help you cope with the illness and its definitive treatment rather than to act alone. I dont know about the eczema girl who died, it is often difficult to tell from these accounts exactly what happened. But no responsible doctor would have advised the parents to ignore conventional medicine. I don’t think this would happen at the Homeopathic Hospital. I went on a visit to the place and met the medical director Dr Sara Eames who was very clear about this. She also told us that all the medical staff have medical qualifications.
Can you have good quackery without bad? Can you have medicine without quackery? I don’t think you can have medicine based on evidence alone. There isn’t enough evidence for one thing. And people are often have health beliefs that are so firm that no amount of statistical information will influence them. The placebo effect, if you want to call it that will often make something happen. If you prefer you can call it the effects of thoughts and feelings being processed by different brain areas resulting in changes in pain perception, sensation, reduced muscular stiffness, improved mood and reduced anxiety etc. etc.
Enough for now!