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You be the judge

Jann Bellamy recently recapped her experience attending a meeting sponsored by her local Healing Arts Alliance. As you re-read her article pay particular attention to the language used by the Alliance to describe themselves and the treatments they offer. For me, there is one word that really stands out. It is emblematic of the attitude of the complementary and alternative medicine community. A word meant to represent a virtue is really a self-serving recusal of critical-thinking. Not wanting to misinterpret their intent, I went the website of the Healing Arts Alliance to get the full context. Here is the mission statement, in full, pasted from their website: (more…)

Posted in: Science and Medicine

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Anti-VEGF treatment of Macular Degeneration: Science-Based Success

Science-Based Medicine authors tend to focus attention on practices that misuse or ignore the tools of science. This is not a criticism. As a daily reader and occasional contributor, I recognize that shining a light on pseudoscience is a critical part SBM’s mission. It is what brings me back day after day. Sometimes, however, it is nice to highlight what real science and real evidence can do.

In my world of treating patients with retinal disease, a revolution has taken place over the past few years. The most aggressive form of macular degeneration has been transformed from a relentlessly progressive, disabling disease to one which can be tamed with medication. Now, patients diagnosed with exudative macular degeneration can expect stabilization and even improvement in vision.

It is a story worthy of a Hollywood movie. Start with a reluctant hero; add controversy, Wall Street, politics, and most important of all, a happy ending.
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Posted in: Clinical Trials, Science and Medicine

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Andrew Weil Flirts with Evidence Based Medicine

Andrew Weil, MD, pops up quite frequently on SBM, most recently in this entry by Harriet Hall, so I will not spend much space introducing him. An excellent biography and critique of Dr. Weil was written by Arnold Relman, former Editor of the New England Journal of Medicine. It is over a decade old, but contemporary to some of the events described in this post, and still quite relevant.

Suffice it to say that Dr. Weil is one of the most successful and well recognized popularizers of alternative medicine. He has authored or coauthored dozens of books. His website sells everything from baby pacifiers to vitamins to breakfast sausages, packaged bearing his name and/or visage. He is an altmed rockstar. He has been a key player in the branding of alternative medicine. In particular, been an advocate of “integration” of traditional and alternative medicine. He has created and exported residency training programs, and more recently proposed board certification in integrative medicine.

I recently read a book entitled On Being Certain: Believing you are right, even when you’re not, by Robert Burton, nicely-reviewed and recommended by Harriet Hall. In his book Dr. Burton excerpted an interview with Dr. Andrew Weil, pointing out Dr. Weil’s profound certainty about the effectiveness of a particular alternative treatment in spite of contradictory evidence. Dr. Hall also discussed this section of the book in her review. I found the excerpts fascinating and decided to delve more deeply into the interview. I also found another interview with Dr. Weil relevant to his ideas about evidence.

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Posted in: Chiropractic

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Anecdotes: Cheaper by the Dozen

A loan officer sets up a meeting with an aspiring entrepreneur to inform him that his application has been denied. “Mr Smith, we have reviewed your application and found a fatal flaw in your business plan. You say that you will be selling your donuts for 60 cents apiece. “Yes” says Mr. Smith, “that is significantly less than any other baker in town. This will give my business a significant competitive advantage!” The loan officer replies, “According to your budget, at peak efficiency the cost of supplies to make each donut is 75 cents, you will lose 15 cents on every donut you sell. A look of relief comes over Mr. Smith’s face as he realizes the loan officer’s misunderstanding. He leans in closer, and whispers to the loan officer “But don’t you see, I’ll make it up in volume.”

If you find this narrative at all amusing, it is likely because Mr. Smith is oblivious to what seems like an obvious flaw in his logic.

A similar error in logic is made by those who rely on anecdote and other intrinsically biased information to understand the natural world. If one anecdote is biased, a collection of 12 or 1000 anecdotes multiplies the bias, and will likely reinforces an errant conclusion. When it comes to bias, you can’t make it up in volume. Volume makes it worse!

Unfortunately human beings are intrinsically vulnerable to bias. In most day to day decisions, like choosing which brand of toothpaste to buy, or which route to drive to work, these biases are of little importance. In making critical decisions, like assessing the effectiveness of a new treatment for cancer, these biases may make the difference between life and death. The scientific method is defined by a system of practices that aim to minimize bias from the assessment of a problem.

Bias, in general, is tendency that prevents unpredjudiced consideration of a question (paraphrased from dictionary.com). Researchers describe sources of bias as systematic errors. A few words about random and systematic errors will make this description clearer.
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Posted in: Clinical Trials, Science and Medicine

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The Plausibility Problem

From the very outset, the founders of Science Based Medicine have have emphasized the importance of plausibility in the critical evaluation of scientific claims in medicine. What exactly does “plausibility” mean, and how should we apply it in science? My simple definition of plausibility would be “the likelihood that a premise is true.” The application in science is a little more complicated.

Consciously or unconsciously, we all consider plausibility in interpreting events in our lives. For example, if one of your coworkers showed up late for work and grumbled about a traffic jam, you would likely accept his story without question. If, instead, the same coworker attributed his tardiness to an alien abduction, you would not be so charitable. In each case, he has provided the same level of evidence: his anecdotal account. You are likely to accept one story and reject the other because of a perceived difference in the plausibility. The skeptic’s mantra “Extraordinary Claims Require Extraordinary Evidence” expresses this concept in a qualitative way.

Evidence-based medicine has traditionally ignored plausibility when interpreting the evidence for a medical intervention. Science-based medicine, as envisioned by the creators of this blog, includes plausibility when making these judgements.

Since experiment research employs rigorous controls, and statistical criteria, you might assume that plausibility is not an issue, however, this is not entirely true. An article written by John Ioannidis entitled “Why Most Published Research Findings Are False” is cited frequently as a reference for the impact of plausibility on the interpretation of research results. This article enumerates numerous factor leading to erroneous research conclusions. Most of them have been dealt with on this blog at one time or another. To me, the most eye-opening aspect of the paper was a quantitive approach to the influence of plausibility in interpreting positive research findings. I was never taught this approach in medical school, or in any other venue. When it comes to implausible hypotheses, the traditional P-value can be very misleading.

As good as Ioannidis’ article is, it is not easy reading for the statistically or mathematically challenged. What I attempt to do in this post is to demonstrate the importance of plausibility in graphic format, without a lot of complex math. If you can grasp the concepts in this post, you will have an understanding that many researchers, and consumers of research, lack.
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Posted in: Basic Science, Clinical Trials

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Integrative Fire-Fighting

Having a housefire is a one of the most stressful, dehumanizing experiences a family can experience. Like cancer, fires appear unexpectedly, and fill victims with fear, grief, and hopelessness. Western firefighting methods do not adequately meet the needs of these victims. No one knows your house as well as you do, yet firefighters take a very paternalistic approach, removing you from the decision-making process, then leaving you to clean up their mess. In the same spirit as integrative oncology, advocates of integrative firefighting believe that families, practitioners of conventional firefighting, as well as advocates of alternative firefighting philosophies should work as a team to achieve their common goals. The integrative approach offers victims choices, and empowers them by inviting them to participate in their own journey through the extinguishing process.

The first fire department was in ancient Rome and provided free firefighting services to citizens. Today firefighting services are a dominated by a consortium of of big business (producers of firefighting equipment) the government (public works) and a militia of mercenary firefighters, collectively known a “Big Hydrant.” This alliance has resulted in a proliferation of expensive, impersonal technology, but firefighting results have not improved since the times of the ancient Romans.
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Posted in: Humor

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Acupuncture for Amblyopia

An recent article in the journal Ophthalmology reported the results of a clinical trial that evaluated acupuncture as an adjunctive treatment for anisometropic amblyopia. In the abstract, the authors conclude:

Acupuncture is a potentially useful complementary treatment modality that may provide sustainable adjunctive effect to refractive correction for anisometropic amblyopia in young children. Further large-scale studies seem warranted.

A little background information is in order.

In a healthy visual system the various structures in the eye focus light ambient light to form a sharp image on the retina. The retina functions like the CCD in a digital camera. Light energy is transduced to electrical signals, which are transmitted through the optic nerve. The signals from the optic nerve are relayed to the occipital cortex (at the very back of the brain) where they are interpreted into the experience of vision.

Amblyopia is often called “lazy eye”. If during childhood the brain is deprived of quality visual information it does not mature properly and loses the potential for good vision. Any opacity within the eye which significantly degrades the quality of the image forming on the retina (such as congenital cataract) can cause amblyopia. Strabismus (misalignment of the 2 eyes) can also cause amblyopia. If the eyes are not aligned, the brain has difficulty reconciling the disparate images from the 2 eyes. In order to avoid double vision the brain may “ignore” the input from one eye, and corresponding part of the visual cortex will not develop properly. Extreme, uncorrected, refractive errors (nearsightedness, farsightedness or astigmatism) can cause amblyopia. Patients with different refractive errors in their 2 eyes, a condition known as anisometropia, can also develop amblyopia in one eye.
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Posted in: Acupuncture, Ophthalmology, Science and Medicine

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