Book review: The Great Cholesterol Myth

Title: The Great Cholesterol Myth (2012)

Authors: Jonny Bowden and Stephen Sinatra

Publisher: Fair Winds Press

There is nothing I like more than finding out that something that has been widely believed for decades is wrong. The cholesterol myth fits the pattern of so many items in my blog: it sounds good, it superficially makes sense, and there is a biologically plausible explanation, but when put to the (scientific) test, it fails.

Unintended consequences and the homeostasis of risk

I recently saw a patient who broke her ankle slipping on the shiny yellow paint they use to highlight the edges of steps. Is this an example of the law of unintended consequences, or the theory of risk homeostasis (risk compensation)? Either way, a well-intended intervention backfired (what the CIA colourfully label ‘blowback’), a phenomenon more common than we think.

Web review: Skeptical Medicine

Skeptical Medicine is a website, not a blog, and I highly recommend it. It contains material from a single author, covering topics related to the scientific basis of medicine: reason, logic, argument, bias, and the philosophy of science. It is extremely well written and referenced but most importantly, it is reasoned, logical and, well, very scientific. For anyone wondering what it is to be skeptical – to take a scientific view of any subject (not just medicine) – then this is the site to read.

Lessons from history #7: medically induced thyroid cancers

In the 1940s to 1960s, children with an upper respiratory illness were often thought to have an enlarged thymus gland (in the neck), and were given some radiation therapy to settle it down. The thymus shrank after being irradiated and the kids generally got better, so the practice continued. It didn't matter that this was not a real disease, or that the treatment was not appropriate, or that the kids would have improved anyway; doctors did something and the patients got better. That, and some cockamamie biological explanation, was all the doctors needed. Well, that and some insurance to cover the medical costs of the kids who got cancer as a result of the radiation.

Is medical practice running ahead of the evidence?

Recently, while debating a respected colleague regarding a shift in practice towards treatment X, despite a lack of evidence showing its superiority, my colleague said: “But we know that practice always runs ahead of the evidence”. He was implying that the evidence would one day catch up and justify the practice. I wondered if medical practice really was running ahead of the evidence, or whether it was running away from it.

When clinical practice does run away from the evidence, we tend to spend our time gathering evidence to support the current practice, instead of using an objective evaluation of the current evidence to inform future practice. This is known as putting the cart before the horse. It is also known as Confirmation Bias.

Tennis elbow treatment: perception versus reality

For decades, surgeons have been reporting good results with surgery for tennis elbow. In a classic article from 1961, the late, great British surgeon RS Garden, reported that the results of surgery for tennis elbow were such that “no patient failed to benefit in some way from the operation”. Fifty years later in a review of 80 patients undergoing surgery for tennis elbow, 78 were reported to have improved. There are plenty of non-surgical treatments out there for tennis elbow (lateral epicondylitis) - all of them are reported as having good results, yet none of them are any better than placebo. Why then, did it take until now for a randomised trial to be done comparing real surgery with sham surgery?

Book Review: The Truth About Drug Companies

Title: The truth about drug companies: how they deceive us and what to do about it (2004)

Author: Marcia Angell

Publisher: Random House, New York

Marcia Angell was an editor for a leading medical journal (the New England Journal of Medicine) from 1979 to 2000, and she is an outspoken critic of big pharma. In this book, she spells out why, and makes a compelling case for being sceptical about the medical information we receive, whether it be from journals, companies, doctors or interest groups. The extent to which that information is biased towards pharmaceutical companies (and their products) remains underestimated.

Trends, forests and trees

How many times have you seen the results of a new way of doing things, where the results after the introduction were shown to be better than they were before? These ‘before-and-after’ studies almost always show an improvement, but does that mean that the improvement was caused by the intervention? Given the example I will show you below, you should conclude that our highly evolved tendency to read cause-and-effect into any association often runs counter to reality.

Book review: The wisdom of the body

Title: The wisdom of the body (1932, 1939)

Author: Walter B Cannon

Publisher: W.W. Norton & Company, New York

This book is old, but its subject and its message still hold. The book is about homeostasis: how the body adapts to keep things in equilibrium, despite forces that attempt to change the balance. This provides an important lesson to those who attempt to influence the balance of anything in the human body: the body will adapt, making the intervention less effective. A lesson that many do not learn.

Book review: Meaning, Medicine and the Placebo Effect

Title: Meaning, Medicine and the Placebo Effect (2002)

Author: Daniel Moerman

Publisher: Cambridge University Press

In this book, an anthropologist offers an outsider’s view of medicine. The book is not restricted to an examination of the placebo effect (in fact, the author suggests abandoning the term, instead using “meaning response”); it asks readers to see all of medicine (and indeed biology) in its social and cultural context. The author shows that much of what we “know” isn’t necessarily true (or more confusingly, that it might be true in certain contexts). In that vein, he criticises doctors for dressing in science (empirical evidence), but practicing experiential evidence, and therefore not being able to see that what they “know” (based on tradition and their own experience) might not be true (despite being able to construct biological mechanisms to explain the perceived effect).

Lessons from history #6: The Vioxx saga

The Vioxx saga contains everything: conflicts of interest, big pharma influence, dodgy government regulators, data fabrication, and a body count. But there is more to the story: it is an example of a common logical fallacy whereby, when faced with a study that shows treatment A to be better than treatment B, we assume that treatment A is providing a benefit, and not that treatment B is harmful. Both assumptions may be equally valid, but we tend to choose the former. Had we not done so in this case, Vioxx might not have harmed so many people.

Book review: Rethinking Aging: Growing Old and Living Well in an Overtreated Society

Title: Rethinking Aging: Growing Old and Living Well in an Overtreated Society (2011)

Author: Nortin M Hadler

Publisher: University of North Carolina Press, Chapel Hill

In his latest offering, Dr Hadler rehashes and updates many of his familiar arguments (breast and prostate screening, cardiac stents, osteoporosis, antidepressants, back surgery), this time applying them to the elderly. He adds material specifically about growing frail and dying, and as usual, he provides considerate, accurate, useful and often counter-intuitive information for the would-be health care consumer.

Keeping childbirth normal

The variation in cesarean section operation (C-section) rates during childbirth is well documented; between hospitals, states and countries. The rates also vary over time, but here the pattern is at least consistent: the rate is increasing. So what? Sure there are complications, but isn’t that worth it if we are saving lives? As usual, it turns out that we have been overestimating the benefits and underestimating the harms of C-sections, which may explain the overuse of this treatment.

The antioxidant myth

A recent Scientific American article challenges the myth of antioxidants being associated with ageing. This is not the first time SciAm has covered this topic (here, here and here). The article challenges current perceived wisdom, not only regarding the effectiveness of anti-oxidants but of the underlying theory that oxidative damage causes ageing.  The current evidence tells us that antioxidant supplementation is not only ineffective, it is harmful. The sorry story of antioxidants should really be one of my “Lessons from History” blogs, except that it has not yet been relegated to history. But the story still provides lessons.

Ethical double standards

Ethics committees (IRBs in the US) are now firmly entrenched in the research environment such that clinical research can only be performed with their approval. Clinical practice, however, is not subject to such approval, yet in many cases the risk of harm (individually and to society) from clinical practice is greater. Are researchers being held to a higher standard than clinicians? Has our concentration on ethical standards for clinical research led to an ethical blind spot for clinical practice?

Don’t just do something, stand there

This reversal of a commonly used phrase is a plea. A plea against the bias that leans doctors towards diagnosing and treating, even when the scientific evidence may not support it. Sure, it is expected that a doctor will diagnose and treat you, but sometimes there is no diagnosis or effective treatment, and pursuing either may be harmful. When in doubt, your doctor will continue to run tests until something comes up, and will continue to treat you for as long as you return with symptoms. Sometimes, not pursuing a diagnosis and not treating a patient are reasonable options. Sometimes they are the best option.

Book review: Limits to Medicine

Title: Limits to Medicine. Medical Nemesis: The Expropriation of Health (1975)

Author: Ivan Illich

Publisher: Marion Boyars

Ivan Illich was a philosopher and historian who published several books in the 1970s targeting areas like medicine, transport, education and energy use. His thesis was that modern, western, industrialisation and in particular the institutionalization of specialised knowledge by the professions has far-reaching negative consequences. His 1975 book Limits to Medicine. Medical Nemesis: The Expropriation of Health made his case against modern, institutionalised medicine. He felt that more expensive and specialised medicine was more likely to be harmful and less effective, and that important aspects of the life experience such as birth, mating, suffering, aging and dying were being medicalized. His points were interesting and controversial in their time, and the following 40-odd years of growth in specialised industrial medicine has made many of them prescient.

Lessons from history #5: Bone marrow transplant for breast cancer

In the 1990s, giving patients with breast cancer massive doses of chemotherapy or radiotherapy followed by a bone marrow “rescue” was thought to improve survival and even cure the disease. It was complex, expensive and risky, which only raised the perceived effectiveness. The treatment spread, and insurance companies had to fall in line to cover the treatment due to legal, government and public pressure. The randomised trials that were eventually done showed that it was no more effective than standard treatment. Here is the story and the lessons that can be learned.

Evidence based medicine vs the Golden Rule

I am a big fan of evidence based medicine (EBM). Not the cookbook type (“do it this way or else”), but the idea that medicine is a science and therefore should be approached scientifically. We should use the principles of logic and rational thinking to reduce the errors that result from our often irrational, subjective “human” way of making decisions. Sometimes, however, we try to use EBM to justify something that doesn’t need scientific support – something that should be the default, and only changed if there is evidence against it. Something like the Golden Rule.

What's the deal with those bad hip replacements?

Most people are aware that a year or two ago there were some new hip replacements that were recalled. The story behind it has all the ingredients to suit this blog: overestimation of benefit, underestimation of harm, regulation failure, and conflict of interest up the wazoo. The ‘deal’ as it were, was a bad one for patients, a bad one for the company (in the end), but a great one for the surgeons, as it became the gift that keeps giving.