Sunday, January 24, 2010

Abusing the placebo effect


Take two pills and drink plenty of liquids, or you can use the pills to sweeten your coffee. Homeopathy has been around since 1796, the result of a false syllogism by one Samuel Hannemann, and it is very big in my neighborhood. A local private school’s house physician is a homeopath. Fortunately, the year my daughter went to that school she did not get sick so I didn’t have to explain to anyone why he was getting nowhere near her.

Homeopahty is the notion that symptoms of a disease can be cured by administering extremely small amounts of a substance that will produce the same symptoms in a healthy person, the “law of similars.” Two centuries of scientific study have failed to show the slightest evidence it actually works.

The fine British science writer David Bradley found an interesting letter in a rather obscure British medical journal, Trends in Pharmacological Sciences, suggesting that homeopath even fails as a placebo instigator.

What’s wrong with giving a patient a placebo? The letter, written by Edzard Ernst at the Universities of Exeter and Plymouth, argues there are two kinds of professionals who prescribe homeopathic remedies. One, the people who actually believe it works. They give it to patients and patients get better. They get better, of course because in most cases, when you are sick your body just gets better if you leave it alone, and because of the placebo effect. Ernst argues those practitioners are simply unethical.

The other kind prescribes homeopathic remedies because of the placebo effect. What does it matter how the patient gets well as long as the patient gets well. I'll give you this pill, you think it will make you better, and often it will. The logic, Ernst writes, is “ethically flawed.”

It would, almost by definition, involve deceiving patients. If we tell our patients that a homeopathic remedy is devoid of specific therapeutic effects, we cannot expect them to respond with clinical improvement. To generate a positive response, we must maximise expectations — and this can only be achieved by using deception. Not telling the truth undermines trust and is unethical. What follows is simple: the prescription of homeopathic medicines is in conflict with fundamental principles of medical ethics.

More important, of course, is that the patient might use the homeopathic remedy instead of getting scientifically based treatment, something I see around here. In the case of a life-threatening disorder, that is serious stuff. For instance, the UK organization of homeopaths has been advertising they have been successfully treating flu for two centuries. They have not.

The main argument against homeopathic remedies as useful placebos is that a physician can make use of the placebo effect without actually administering a placebo. Just tell the patient this antibiotic is an absolute wonder drug, it always works,  and you have given the patient real medicine and added the benefit of a placebo. Giving homeopathic compounds may produce the placebo effect but does absolutely nothing else--except provide income for the practitioner.

By the way, Bradley has calculated that the effects of a homeopathic compound actually working--he uses a compound with less than one molecule of sulfur--is 600,000,000,000,000,000,000,000 to 1 against.

3 comments:

David Bradley said...

Thanks for the shout out Joel! Much appreciated. I was going to say you're one in a million, but it's probably closer to one in 600,000,000,000,000,000,000,000 homoeapathically speaking ;-)

Susan said...

Any guess as to why homeopathy has seen such a resurgence recently?

Susan Volkmar

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