One of the themes of science-based medicine is to be suspicious of any form of medicine that is not science-based. In other words, beware of dodgy qualifiers placed before “medicine,” such as: “alternative”, “integrative”, or “complementary” – those that imply that something other than science or evidence is being used to determine which treatments are safe and effective. I would also include “traditional Chinese” medicine in the dodgy category. A recent article defending Traditional Chinese Medicine (TCM) provides, ironically, an excellent argument for the rejection of TCM as a valid form of medicine. The authors, Jingqing Hua and Baoyan Liub, engage in a number of logical fallacies that are worth exploring.
Their introduction sets the tone:
Traditional Chinese medicine (TCM) has a history of thousands of years. It is formed by summarizing the precious experience of understanding life, maintaining health, and fighting diseases accumulated in daily life, production and medical practice. It not only has systematic theories, but also has abundant preventative and therapeutic methods for disease.
It may be trivially true that TCM has a long history, but it is hard to ignore that the placement of this statement at the beginning of a scientific article implies an argument from antiquity – that TCM should be taken seriously because of this long history. I would argue that this is actually a reason to be suspicious of TCM, for it derives from a pre-scientific largely superstition-based culture, similar in this way to the pre-scientific Western culture that produced the humoral (Galenic) theory of biology.
A new review published in the BMJ once again opens the question of the risks vs benefits of daily aspirin as a prevention for heart attacks and strokes. The reviewers looked at nine randomized trials involving over 100,000 patients and found that aspirin is effective in reducing heart attacks and strokes, but also increases the risk of gastrointestinal bleeding and that in some patients this risk outweighs the benefit.
This is an old and enduring controversy, and one with significant public health ramifications. Aspirin is an anti-platelet agent – it inhibits platelets, the cell fragments in the blood that are the first line against bleeding, from aggregating (clumping together). Platelets aggregate in order to quickly stop bleeding from damaged veins or arteries. But they can also aggregate around cholesterol plaques in arteries, causing a large thrombus (blood clot) that can block off the artery, or that can break off and lodge in a downstream artery (an embolus) and cause a stroke or heart attack.
By inhibiting platelet aggregation daily aspirin reduces the risk of forming a thrombus or embolus, and thereby reduces the risk of heart attack or stroke. Of course, the real story is always more complex than our straightforward explanations. There is some research to suggest that the anti-inflammatory effects of aspirin may also be important to their role in reducing vascular risk. The relative contribution of anti-platelet and anti-inflammatory effects have not been fully teased out. Further, the anti-inflammatory effects of daily aspirin may have non-vascular benefits, like reducing the risk of some cancers.
Tonsillectomy remains a common surgical procedure with over half a million cases in the US per year, the most common surgical procedure in children. The indications and effects of tonsillectomy remain a matter of research and debate, as is appropriate. It is also a subject of popular misinformation and alarmism.
A recent article by Seth Roberts raises many of the issues with tonsillectomy, but also reveals the pitfalls of non-experts trying to understand the clinical literature and the effects of bias on evaluating a complex medical question. Throughout the article Roberts displays a persistent bias toward downplaying the benefits and exaggerating the risks of tonsillectomy, while accusing the medical establishment of doing the exact opposite. The purpose of this post is not to defend the practice of tonsillectomy but to review some of the relevant issues and explore how bias can affect an assessment of the evidence.
Indications for Tonsillectomy
Roberts tells the story of Rachael who was offered tonsillectomy for her son and so did some research on her own. She looked on Pubmed (a good place to start) and found a Cochrane review from 2009.
The Cochrane Review that Rachael found (“Tonsillectomy or adeno-tonsillectomy versus non-surgical treatment for chronic/recurrent acute tonsillitis”) was published in 2009. It describes four experiments that compared tonsillectomy to the care a sick child would otherwise receive. All four involved children like Rachael’s son, and all four had similar results: Tonsillectomies had only a small benefit. (Contrary to what Rachael was told.) During the year after random assignment to treatment — the point at which some children had their tonsils removed, other children did not — children whose tonsils were removed had one less sore throat than children who were not operated on (two instead of three for children like Rachael’s son).
Dr. Ian Gawler, a veterinarian, suffered from osteogenic sarcoma (a form of bone cancer) of the right leg when he was 24 in 1975. Treatment of the cancer required amputation of the right leg. After completing treatment he was found to have lumps in his groin. His oncologist at the time was confident this was local spread from the original cancer, which is highly aggressive. Gawler later developed lung and other lesions as well, and was given 6 months to live due to his metastatic disease.
Gawler decided to embark on an alternative treatment regimen, involving coffee enemas, a vegetarian diet, and meditation. Eventually he was completely cured of his terminal metastatic cancer. He has since become Australia’s most famous cancer survivor, promoting his alternative approach to cancer treatment, has published five books, and now runs the Gawler Foundation.
At least, that is the story he believes. There is one major problem with this medical tale, however – while the original cancer was confirmed by biopsy, the subsequent lesions were not. His oncologist at the time, Dr. John Doyle, assumed the new lesions were metastatic disease and never performed a biopsy. It was highly probable – the timing and the location of the new lumps following a highly aggressive cancer. But even a diagnosis that is 95% likely will be wrong in 1 patient out of 20 – which means a working physician will have patients with the 5% diagnosis about once a week. The standard of practice today would be to do a biopsy to get tissue confirmation of the diagnosis, and rule out the less likely alternatives.
Labels are a cognitive double-edged sword. We need to categorize the world in order to mentally capture it – labels help us organize our mental maps of the overwhelming complexity of things and to communicate with each other. But labels can also be mental prisons, when they substitute for a thorough, nuanced, or individualized assessment – when categorization becomes pigeon-holing.
We use many labels in our writings here, out of necessity, and we try to be consistent and thoughtful in how we define the labels that we use, recognizing that any sufficiently complex category will be necessarily fuzzy around the edges. We have certainly used a great deal of electrons discussing what exactly is science-based medicine, and that the label of so-called alternative medicine is really a false category, used mainly for marketing and lobbying (hence the caveat of “so-called”).
We get accused of using some labels for propaganda purposes, particularly “antivaccinationist” (often shortened to “antivaxer”). Also “denier” or “denialist”, as in germ-theory denier. Even though we often apply labels to ourselves, no one likes having an unflattering label applied to them, and so we have frequent push-back against our use of the above terms.
There are many medical pseudosciences that persist despite a utter lack of either plausibility or evidence for efficacy. Some practices emerged out of their culture of origin, or out of the prevailing ideas of a pre-scientific age, while others were manufactured out of the imagination of perhaps well-meaning but highly misguided individual practitioners. They were just made up – homeopathy, for example, or subluxation theory.
Iridology belongs to this latter category – a system of diagnosis that was invented entirely by Ignatz Peczely, a Hungarian physician who first published his ideas in 1893. The story goes that Peczely as a boy found an owl with a broken leg. At the time he noticed a prominent black stripe in the iris of one eye of the owl. He nursed the bird back to health and then noticed that the black line was gone, replaced by ragged white lines. From this single observation Peczely developed the notion of iridology.
Peczely’s idea was that the iris maps to the rest of the body in some way, and therefore the flecks of color in the iris reflect the state of health of the various body parts. This basic approach to diagnosis or treatment is called the homunculus approach – the idea that one part of the body maps to the rest of the body, including the organ systems. Reflexology, auricular acupuncture, and even straight chiropractic follow this approach.
At SBM our mission is to promote the highest standards of science in medicine, and to explore exactly what that means, both in the specific and the general. We do spend a lot of space criticizing so-called CAM (complementary and alternative medicine) because it represents a semi-organized attempt to reduce or even eliminate the science-based standard of care, and to sow confusion rather than clarity as to how science works and what the findings of medical science are.
CAM proponents tend to use the same bad arguments over and over again. They have no choice (other than deciding not to be CAM proponents) – if a treatment were backed by solid logic and evidence it would not be CAM, it would just be medicine. As SBM’s fourth year comes to a close I thought I would round up the most common bad arguments that CAM proponents put forward to defend their position. Like creationists, pointing out the errors in their facts and logic will not stop them from continuing to use these arguments. But this lack of imagination on their part makes it somewhat easy to counter their arguments, since the same ones will come up again and again.
The argument from antiquity
Our SBM colleagues in Australia have been critical of the incorporation of unscientific methods into academia. In defense of this practice:
Professor Iain Graham from Southern Cross University’s School of Health yesterday defended his university, saying the use of alternative therapies, such as homeopathy, can be traced as far back as ancient Greece.
This is a common claim – that some CAM modalities have been around for centuries, or even thousands of years, and so they must work. I am not sure if professor Graham intended to state that homeopathy can be traced back to ancient Greece, perhaps he just meant that some CAM therapies can, and chose homeopathy as a bad example. For the record, homeopathy was invented by Samuel Hahnemann about 200 years ago.
Michael Specter is a good science journalist. I particularly enjoyed his book, Denialism. In a recent New Yorker article he tackles the difficult question of the placebo effect in modern medicine. While he does a fair job of hitting upon the key points of this question, I think he missed some important aspects of this question and allowed the views of Ted Kaptchuk to overly influence the framing of the article. Specter fell for the typical journalist trap — frame the article around a charismatic “maverick”, complete with compelling anecdotes, bury the meat of legitimate skepticism deep in the article, but then bring it all back to the maverick in the end. Be sure to tell us how this is going to change everything. This is good story telling, but very problematic as science journalism.
Kaptchuk himself is an interesting character. He is heading Harvard’s Program in Placebo Studies and the Therapeutic Encounter. He has produced some good science on the placebo effect, but does not seem to want to draw the appropriate lessons from that research, and passes his bias on to Specter. From the article the quotes from Kaptchuk that most strike me are those about his personal experience with placebo medicine. Specter reports:
“There was no fucking way needles or herbs did anything for that woman’s ovaries,” he told me, still looking mystiﬁed, thirty-ﬁve years later. “It had to be some kind of placebo, but I had never given the idea of a placebo effect much attention. I had great respect for shamans—and I still do. I have always believed there is an important component of medicine that involves suggestion, ritual, and belief—all ideas that make scientists scream. Still, I asked myself, Could I have cured her? How? I mean, what could possibly have been the mechanism?”
Four months ago David Gorski wrote about the College of Physicians and Surgeons of Ontario’s (CPSO) draft policy on “non-allopathic” medicine. He pointed out:
It’s obvious from the wishy-washy approach to the scientific basis of medicine, the waffle words when it comes to whether an “allopathic” physician should support “non-allopathic” therapies, and the apparently inadvertent use of language favored by quacks that there were far too many “alternative” practitioners involved in drafting this policy.
I agree. The proposed policy addresses the issue of so-called complementary and alternative medicine (CAM) and has drawn serious criticism from Canadian physicians (at least those who are paying attention and have the slightest clue about what is going on). The backlash is good to see, but it is not nearly vigorous enough.
There is now an update to this story as the CPSO has published a revised policy proposal. There are some improvements, based on the criticism, but still there are problems with the policy.
Prince Charles is a big supporter of “natural” medicine, which in practice means unscientific and ineffective medicine. He has no particular expertise in this area, and there is absolutely no legitimate reason why he should have any influence over the practice of medicine in the UK. But he is the Prince of Wales, and he has chosen to use that celebrity to promote CAM.
Prince Charles has also recently been criticized for his credulous support for medical nonsense. The Telegraph recently reported that Simon Singh, co-author with Edzard Ernst of Trick or Treatment, and exposer of CAM pseudoscience, spoke about Prince Charles at the recent Hay Festival in India. Singh had some sharp criticism, including:
He only wants scientific evidence if it backs up his view of the natural treatment of health conditions…
We presented evidence that disputes the value of alternative medicine and despite this he hasn’t changed his mind…