Archive for Science and Medicine

The continuum of surgical research in science-based medicine

Editor’s note: Three members of the SBM blogging crew had a…very interesting meeting on Friday, one none of us expected, the details of which will be reported later this week–meaning you’d better keep reading this week if you want to find out. (Hint, hint.) However, what that means is that I was away Thursday and Friday; between the trip and the various family gatherings I didn’t have time for one of my usual 4,000 word screeds of fresh material. However, there is something I’ve been meaning to discuss on SBM, and it’s perfect for SBM. Fortunately, I did write something about it elsewhere three years ago. This seems like the perfect time to spiff it up, update it, and republish it. In doing so, I found myself writing far more than I had expected, making it a lot more different from the old post than I had expected, but I guess that’s just me.

In the meantime, the hunt for new bloggers goes on, with some promising results. If we haven’t gotten back to you yet (namely most of you), please be patient. This meeting and the holiday–not to mention my real life job–have interfered with that, too.

The continuum of surgical research in science-based medicine

One of the things about science-based medicine that makes it so fascinating is that it encompasses such a wide variety of modalities that it takes a similarly wide variety of science and scientific techniques to investigate various diseases. Some medical disciplines consist of mainly of problems that are relatively straightforward to study. Don’t get me wrong, though. By “straightforward,” I don’t mean that they’re easy, simply that the experimental design of a clinical trial to test a treatment is fairly easily encompassed by the paradigm of randomized clinical trials. Medical oncology is just one example, where new drugs can be tested in randomized, double-blinded trials against or in addition to the standard of care without having to account for many difficulties that arise from difficulties blinding. We’ve discussed such difficulties before, for instance, in the context of constructing adequate placebos for acupuncture trials. Indeed, this topic is critical to the application of science-based medicine to various “complementary and alternative medicine” modalities, which do not as easily lend themselves to randomized double-blind placebo-controlled trials, although I would hasten to point out that, just because it can be very difficult to do such trials is not an excuse for not doing them. The development of various “sham acupuncture” controls, one of which consisted even of just twirling a toothpick gently poked onto the skin, shows that.

One area of medicine where it is difficult to construct randomized controlled trials is surgery. The reasons are multiple. For one thing, it’s virtually impossible to blind the person doing the surgery to what he or she is doing. One way around that would be to have the surgeons who do the operations not be involved with the postoperative care of the patients at all, while the postoperative team doesn’t know which operation the patient actually got. However, most surgeons would consider this not only undesirable, but downright unethical. At least, I would. Another problem comes when the surgeries are sufficiently different that it is impossible to hide from the patient which operation he got. Moreover, surgery itself has a powerful placebo effect, as has been shown time and time again. Even so, surgical trials are very important and produce important results. For instance, I wrote about two trials for vertebral kyphoplasty for ostoporotic fractures, both of which produced negative results showing kyphoplasty to be no better than placebo. Some surgical trials have been critical to defining a science-based approach to how we treat patients, such as trials showing that survival rates are the same in breast cancer treated with lumpectomy and radiation therapy as they are when the treatment is mastectomy. Still, surgery is a set of disciplines where applying science-based medicine is arguably not as straightforward as it is in many specialties. At times, applying science-based medicine to it can be nearly as difficult as it is to do for various CAM modalities, mainly because of the difficulties in blinding. That’s why I’m always fascinated by strategies by which we as surgeons try to make our discipline more science-based.

Posted in: Clinical Trials, Science and Medicine, Surgical Procedures

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Mercola, Gardasil, and Toyota?

Joseph Mercola, D.O. should be well known to readers of SBM for reflexively opposing science-based medicine while providing an endless stream of misinformation on his blog, advocating detoxification, homeopathy, the tapping of meridians chiropractic and more at his clinic, and peddling a treasure trove of vitamin supplements, foods, and Mercola-endorsed devices (on sale at his site for your convenience, no conflict of interest there!).

Nothing seems to personify the evil of modern medicine to Dr Mercola more than the concept of vaccination, and Gardasil, the vaccine against human papillomavirus (HPV), has been drawing a good deal of his ire of late.  Case in point is this train-wreck of a post comparing the recent Toyota recall to Gardasil entitled “Time for the Truth About Gardasil.”  The post is ill-named.

It begins:

Cervical cancer accounts for less than 1 percent of all cancer deaths — so it was somewhat surprising when the U.S. Food and Drug Administration fast-tracked approval of Gardasil, a Merck vaccine targeting the human papilloma virus that causes the disease. (more…)

Posted in: Science and Medicine, Vaccines

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My NCCAM Wish List

For a number of reasons, well-argued many times here on SBM, it would be beneficial to American citizens if the National Center for Complementary and Alternative Medicine (NCCAM) were abolished. This does not seem to be in the cards anytime soon. Here, then, are my suggestions for making the Center less dangerous and less of a marketing tool for pseudomedicine than it has been since its inception. Some suggestions might even make the Center somewhat useful. They are listed in order of priority. The Center should:

1. Abandon all unethical trials, beginning with the Trial to Assess Chelation Therapy (TACT, which is under the joint auspices of the NHLBI). This should be done in a very public manner. The reasons for abandoning the TACT, in summary, are as follows.


Posted in: Medical Ethics, Politics and Regulation, Science and Medicine

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Less salt: it’s that simple

It has been known for decades that dietary sodium is significantly associated with hypertension and coronary heart disease.  Despite this knowledge, Americans continue to consume more sodium, most of it coming from processed foods.  Various approaches have been used to help individuals modify their behavior, one of the most popular of which is the DASH diet.  Given what we know, you would think that a low-sodium diet would be especially popular with “alternative” practitioners.  After all, what could be more “natural” than lifestyle modification (a mainstay of real medicine since…well…forever).

But as any clinician knows, it’s much easier to get someone to take something than to eliminate something.  Lifestyle modification is difficult, but achievable to a degree as experience has shown with cholesterol, smoking, and other modifiable risk factors.  A recent study in the New England Journal of Medicine evaluated what the possible effect would be of lowering U.S. sodium consumption to 3g/day.  The authors found that, “Modest reductions in dietary salt could substantially reduce cardiovascular events and medical costs and should be a public health target.”


Posted in: Science and Medicine

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Being Negative Is Not So Bad

A new study published in PLOS Biology looks at the potential magnitude and effect of publication bias in animal trials. Essentially, the authors conclude that there is a significant file-drawer effect – failure to publish negative studies – with animal studies and this impacts the translation of animal research to human clinical trials.

SBM is greatly concerned with the technology of medical science. On one level, the methods of  individual studies need to be closely analyzed for rigor and bias. But we also go to great pains to dispel the myth that individual studies can tell us much about the practice of medicine.

Reliable conclusions come from interpreting the literature as a whole, and not just individual studies. Further, the whole of the literature is greater than the sum of individual studies – there are patterns and effects in the literature itself that need to be considered.


Posted in: Science and Medicine

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“Vaccines didn’t save us” (a.k.a. “vaccines don’t work”): Intellectual dishonesty at its most naked

If there’s one thing about the anti-vaccine movement I’ve learned over the last several years, it’s that it’s almost completely immune to evidence, science, and reason. No matter how much evidence is arrayed against it, its spokespeople always finds a way to spin, distort, or misrepresent the evidence to combat it and not have to give up the concept that vaccines cause autism. Not that this is any news to readers of this blog, but it bears repeating often. It also bears repeating and emphasizing examples of just the sort of disingenuous and even outright deceptive techniques used by promoters of anti-vaccine pseudoscience to sow fear and doubt about vaccines among parents. These arguments may seem persuasive to those who have little knowledge about science or epidemiology. Sometimes they even seemed somewhat persuasive to me; that is, at least until I actually took the time to look into them.

One example of such a myth is the claim that “vaccines didn’t save us,” also sometimes going under the claim that “vaccines don’t work.” The anti-vaccine website Vaccine Liberation has a large set of graphs purporting to show that the death rates of several vaccine-preventable diseases, including whooping cough, diptheria, measles, and polio were falling before the vaccines for each disease were introduced. The the article quotes Andrew Weil:

Posted in: Science and Medicine, Vaccines

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The case of John Lykoudis and peptic ulcer disease revisited: Crank or visionary?

One of the themes of SBM has been, since the very beginning, how the paradigm of evidence-based medicine discounts plausibility (or, perhaps more appropriately, implausibility) when evaluating whether or not a given therapy works. One of our favorite examples is homeopathy, a therapy that is so implausible on a strictly scientific basis that, for it to work, huge swaths of well-established science supported by equally huge amounts of experimental and observational evidence would have to be found to be all in serious error. While such an occurrence is not per se impossible, it is incredibly unlikely. Moreover, for scientists actually to start to doubt our understanding of chemistry, biochemistry, pharmacology, and physics to the point of thinking that our understanding of them is in such serious error that homeopathy is a valid description of reality, it would take a lot more than a bunch of low-quality or equivocal studies that show no effect due to homeopathy detectably greater than placebo.

On Friday, Kim Atwood undertook an excellent discussion of this very issue. What really caught my attention, though, was how he educated me about a bit of medical history of which I had been completely unaware. Specifically, Kim discussed the strange case of John Lykoudis, a physician in Greece who may have discovered the etiology of peptic ulcer disease (PUD) due to H. pylori more than a quarter century before Barry Marshall and Robin Warren discovered the bacterial etiology of PUD in 1984. One reason that this story intrigued me is the same reason that it intrigued Kimball. Lykoudis’ story very much resembles that of many quacks, in particular Nicholas Gonzalez, in that he claimed results far better than what medicine could produce at the time, fought relentlessly to try to prove his ideas to the medical authorities in Greece at the time, and ultimately failed to do so. Despite his failure, however, he had a very large and loyal following of patients who fervently believed in his methods. The twist on a familiar story, however, is that Lykoudis may very well have been right and have discovered a real, effective treatment long before his time.

Posted in: Basic Science, Clinical Trials, Science and Medicine

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H. Pylori, Plausibility, and Greek Tragedy: the Quirky Case of Dr. John Lykoudis

Mark Crislip is on vacation, but through an arduous series of shakings and succussions (beating his head against the wall?) we have channeled part of his essence: This post mostly concerns itself with infectious diseases, thanks to several recent posts on SBM that discussed the plausibility of health claims† and that touched on the recent discovery that most peptic ulcer disease (PUD) is caused by a bacterium, Helicobacter pylori. Several comments and statements quoted in those posts reveal recurrent questions regarding both plausibility itself and the history of the H. pylori hypothesis. In this post I’ll attempt to answer some of those questions, but I’ll also insert some new confusion.

Plausibility ≠ Knowing the Mechanism

Let’s first dispense with a simple misunderstanding: We, by which I mean We Supreme Arbiters of Plausibility (We SAPs) here at SBM, do not require knowing the mechanism of some putative effect in order to deem it plausible. This seems so obvious that it ought not be necessary to repeat it over and over again, and yet the topic can’t be broached without some nebbishy South Park do-gooder chanting a litany of “just because you don’t know how it works doesn’t mean it can’t work,” as if that were a compelling or even relevant rebuttal. Let’s get this straight once and for all: IT ISN’T.


Posted in: Basic Science, History, Science and Medicine

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Vaccinations and autism: are we number 1?

It has been alleged by Great Minds such as Jenny McCarthy that the US recommends far more vaccinations than other countries.  Her precise statement was, “How come many other countries give their kids one-third as many shots as we do?” She put this into the context of wondering if our current vaccine schedule should be less rigid.  The entire piece was filled with what could charitably called less-than-truthful assertions, but examining simply this one assertion might be useful.  Dr. John Snyder has an excellent analysis of the most important assertion, that of the possible benefits of an “alternative vaccination schedule”  which I would encourage you to read.

First, we need to parse out this “more shots than everyone else” statement.  Some countries–Haiti, for example–give far fewer vaccines due not to fewer recommendations but to adverse economic conditions. Because of this, they have very high rates of vaccine-preventable diseases.  They want to vaccinate more, but can’t.  Then there are countries who can afford to vaccinate. Let’s look at what three industrialized nations recommend before six years of age.

Vaccinations, by disease and country, 0-6 years of age

Vaccine France Germany USA Iceland
Hepatitis B Yes Yes Yes No
Rotavirus No No Yes No
Diphtheria, tetanus, and pertusis Yes Yes Yes Yes
Hib Yes Yes Yes Yes
Pneumococcus Yes Yes Yes No
Polio Yes Yes Yes Yes
Influenza Not reported Not reported Yes No
Meales, mumps, rubella Yes Yes Yes Yes
Varicella No Yes Yes No
Hepatitis A No No Yes No
BCG (disseminated TB) Yes No No No
Meningococcus No Yes For some Yes

The chart, as I’ve presented it, is somewhat imprecise.  Some vaccinations are given in a single shot, others in multiple shots, but these generally represent the childhood vaccinations in each country, and the links provided will take you to the more detailed information.


Posted in: Science and Medicine, Science and the Media, Vaccines

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Placebo Effects Revisited

In the Wall Street Journal last week was a particularly bad article by Melinda Beck about acupuncture. While there was token skepticism (by Edzard Ernst, of course, who is the media’s go-to expert for CAM), the article credulously reported the marketing hype of acupuncture proponents.

Toward the end of the article Beck admits that “some critics” claim that acupuncture provides nothing more than a placebo effect, but this was followed by the usual canard:

“I don’t see any disconnect between how acupuncture works and how a placebo works,” says radiologist Vitaly Napadow at the Martinos center. “The body knows how to heal itself. That’s what a placebo does, too.”

That is a bold claim, and very common among CAM proponents, especially acupuncturists. As the data increasingly shows that acupuncture (and other implausible treatments) provides no benefit beyond placebo, we hear the special pleading that placebos work also.

But is that true? It turns out there is a literature on the placebo effect itself, and the evidence suggests that placebos generally do not work.


Posted in: Acupuncture, Homeopathy, Science and Medicine

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