Providence based medicine
If the caring practitioner has no idea of what to do next, the decision may be best left in the hands of the Almighty. Too many clinicians, unfortunately, are unable to resist giving God a hand with the decision-making.
New Zealand Medical Journal Vol 113 No 1122 p479
Acupuncture and ACC
I am pleased to report that I received a reply from Dr David Rankin acknowledging the dearth of evidence for the widespread use of acupuncture. ACC are taking a responsible attitude and are commissioning a wide range of studies looking at current treatments in order to assess which of them are truly effective in speeding recovery and the return to work.
Saint Goncalo of the Immaculate Perineum?
Haemorrhoid sufferers are flocking to a church in Portugal in the belief that exposing their afflicted behinds to the statue of a local saint will cure them. I have named this pious act “anoflection”. However, the local Priest drew the line at allowing a young woman to pray naked in the hope that this would cure her severe acne. Given the revelations of widespread sexual abuse by priests, it would appear most unwise to expose oneself in this manner in a church.
Saint Goncalo, a 13th Century priest, also has a history of helping women find husbands. Every June, during a festival in his honour, unmarried men and women exchange penis-shaped cakes as tokens of their affection.
There is clearly no need for our organisation to attack or ridicule religious belief when the Catholic Church is doing it for us. I believe that we should sincerely welcome these quaint rituals into our culture. I look forward to a new range of phallic pastries at my local bakery.
Dominion Post 14/1/03
Placebos and homeopathy
The business of science is generating testable hypotheses. This is the classical approach espoused by Popper who put it in a negative sense in that he proposed that for something to fall within the realms of science, it had to be capable of being falsified (proved wrong). This approach has been criticised by Skrabanek in particular because he felt that nonsensical propositions should not be tested. In this respect Skrabanek raised the idea of having some kind of demarcation of the absurd which would avoid dignifying pseudoscience by testing it. For example, the Popperian approach requires us to test homeopathy in double-blind placebo controlled trials. Skrabanek’s approach would be to argue that homeopathy breaches so many scientific laws that it is already outside the tenure of science.
With respect to homeopathy, it is clear that placebo controlled trials of homeopathy are trials of one placebo against another. This explains the tendency for published trials to fluctuate around a midpoint with some showing a small positive effect and some no effect. The philosophy of David Hume teaches us to suspect either self-delusion or fraud if any published trial of homeopathy shows a dramatic effect of homeopathic solutions in any biological sense. The best example of this is the famous Benveniste study published in Nature. (Davenas et al., Nature, 1988, 333:816). This study could not be replicated by any other laboratory unless the experimental work was done under the supervision of Elizabeth Davenas.
After a team of skeptics (Randi et al) supervised a repeat of the work under their close scrutiny the original results were shown to be a delusion with implications of fraud and Benveniste was summarily sacked. People who believe in homeopathy are in the grip of an enduring delusion. Benveniste is a classic example of this and he has recently published a paper titled “Transatlantic transfer of digitised antigen signal by telephone link” (J. Allergy Clin. Immunol. 99:S175, 1997).
The claim is made that “ligands so dilute that no original molecule remained still retained biological activity”. The abstract is classically incomprehensible pseudoscience and Benveniste has the Gallic arrogance to quote his original discredited trial in the references!
Ginkgo is an herbal type product claimed to enhance and improve memory. Given what I have just written about placebo controlled trials it will come as no surprise that ginkgo provides no measurable benefit in memory or other related cognitive function. This will have absolutely no effect on the sales of this product because if people believe that it works then they will continue to buy it. Those people who sell the product will find endless reasons to defend their promotion of this useless remedy. I referred earlier to science involving the generation of a testable hypothesis. The practitioners and promoters of pseudoscience have become very skilled at generating endless secondary hypotheses to the point where further testing is impossible. Here are some examples:
- The trial was too short/long
- They should have used “x” and not “y” strength ginkgo
- They should have used added vitamin C, selenium etc. etc
Ginkgo for memory enhancement: a randomised controlled trial. Solomon et al. JAMA. 21 Aug 2002. Vol. 288. No.7. p835-40
A reader of the New Zealand Family Physician (Vol 29 Number 6, December 2002 p366) recently took issue with a review of a paper (Knudston et al., JAMA 23 Jan 2002, Vol 287 No. 4 pp481-6) which concluded “there is no evidence to support a beneficial effect of chelation therapy in patients with ischaemic heart disease, stable angina, and a positive treadmill test for ischaemia”. This was a placebo-controlled trial and the conclusions are the same as for similar published trials. The reader, however, objected to the use of an active placebo and claimed that this rendered the conclusions invalid. The debate raises several important issues.
- Chelation quackery is a worldwide growth industry worth millions of dollars. The hypothesis is that symptoms of coronary artery disease (CAD) will improve following the removal (by chelation) of calcium from atherosclerotic plaques in the coronary arteries. Despite an overly simplistic view of CAD it seems like this is a testable hypothesis but wait a minute. Chelation clinics exist all over New Zealand and as yet there are no, and I repeat no double blind placebo controlled trials proving that chelation is more than a placebo. In fact, the Knudston trial is further evidence that chelation is ineffective. There is a worrying trend here, seen also with acupuncture, where unproven therapies are introduced into practice and opponents of such quackery are then challenged to prove that the given therapy is ineffective. I object to this argument. It is up to the proponents of new therapies to prove that their treatments are superior to placebo. In other words, put up or shut up.
- The reader wrote in and objected that the Knudston trial used an active placebo. A placebo is by definition an inert substance. However, some drugs or treatments produce marked effects. For example, if the drug under test caused the patient’s skin to turn green it would be easy for both patient and doctor to determine who was receiving the drug or the placebo. The experiment has become “unblinded” and this is fatal to any conclusions that might be drawn. This problem is well recognized and some trials even invite participants to try and predict whether they received the test drug or the placebo. This is a sensible test of the blinding. Chelation mixtures are based around EDTA, which allegedly leaches calcium out of atherosclerotic plaques. Along with EDTA the preparations contain other drugs such as lignocaine, magnesium, vitamin C. Many of these are vasoactive and cause people to feel flushed or a little euphoric. If a true placebo was used it would not cause these effects and therefore the experiment would have become unblinded. It is therefore sometimes important to use active placebos whose side effects mimic those of the drug under evaluation. For example and I quote: “forty (59%) of 68 of the antidepressant studies published between 1968 and 1972 using an inert placebo control reported the antidepressant as effective, compared to only one (14%) of seven studies using an active placebo (atropine)”. (The Powerful Placebo, Shapiro, page 206). The antidepressants under test all caused a dry mouth and slightly blurred vision as does atropine. The use of an active placebo was clearly very important and shows once again how the expectations and optimism of researchers can lead to a serious overestimate of the efficacy of new drugs.
- Chelation mixtures are non-standard and contain a wide range of drugs in addition to the chelating agent EDTA. This allows quacks to get maximum effect from the generation of endless secondary hypotheses. Suppose we test just EDTA versus placebo and produce the expected result of no effect. The quacks will start bleating that we didn’t have Vitamin C, magnesium, rhubarb, senna pods (pick anything you like) so back to the laboratory. No sooner do you test one combination and they will come up with another. This is the generation of the endless secondary hypotheses and this is a sure sign of a pseudoscience. The hallmark of science is the generation of what Staudenmayer (Environmental Illness: Myth and Reality, Lewis 1999) calls a “hard core postulate” and he goes on to say: “When hard-core postulates cannot explain a phenomenon, auxiliary postulates (ie. Secondary hypotheses) are often invoked to protect them from refutation (ie. being proved wrong).