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Archive for May, 2014

Of the Trial to Assess Chelation Therapy, Bayes, the NIH, and Human Studies Ethics

An experiment is ethical or not at its inception; it does not become ethical post hoc—ends do not justify means.
~ Henry K. Beecher

tact

A couple of weeks ago, Dr. Josephine Briggs, the Director of the National Center for Complementary and Alternative Medicine (NCCAM), posted a short essay on the NCCAM Research Blog touting the results of the Trial to Assess Chelation Therapy (TACT) (italics added):

The authors found that those receiving the active treatment clearly fared better than those receiving placebo. The accompanying editorial in the AHJ reminds readers about the value of equipoise and the need to “test our beliefs against evidence.”

Most physicians did not expect benefit from chelation treatment for cardiovascular disease. I readily admit, initially, I also did not expect we would find evidence that these treatments reduce heart attack, strokes, or death. So, the evidence of benefit coming from analyses of the TACT trial has been a surprise to many of us. The subgroup analyses are suggesting sizable benefit for diabetic patients—and also, importantly, no benefit for the non-diabetic patient. Clearly subgroup analyses, even if prespecified, do not give us the final answer. But it is also clear that more research is needed to test these important findings.

And TACT findings are indeed a reminder of the importance of retaining equipoise [sic], seeking further research aimed at replicating the findings, and neither accepting nor rejecting findings based on personal biases. The scientific process is designed to weed out our preconceived notions and replace them with evidence.

Dr. Briggs concluded:

So, TACT is a reminder—an open mind is at the center of the scientific method.

Dr. Briggs’s title was “Bayes’ Rule and Being Ready To Change Our Minds”, a reference to a recent editorial that had accompanied one of the TACT papers. That editorial, by Dr. Sanjay Kaul, a physician and statistician from UCLA, begins with this quotation:

Preconceived notions are the locks on the door to wisdom.
~ Merry Browne

Here is the relevant passage from Dr. Kaul’s editorial (italics added):

Sixth, it has been argued that the trial was unethical because there was no compelling clinical or preclinical evidence that chelation therapy has significant efficacy against atherosclerotic cardiovascular disease, and given that chelation therapy can cause harm, the risk was not minimal. A Bayesian analysis would not look kindly on the results because of the low prior probability of treatment effect (the so-called implausibility argument).6 This is an uncharitable (and unwarranted) interpretation of the data because previous systematic reviews concluded, “insufficient evidence to decide on the effectiveness or ineffectiveness of chelation therapy in improving clinical outcomes among people with atherosclerotic cardiovascular disease.” It is axiomatic that absence of evidence of efficacy is not the same as evidence of the absence of efficacy.

From a Bayesian perspective, the strength of evidence is often summarized using a Bayes factor, which is a measure of how well 2 competing hypotheses (the null and the alternate) predict the data. The Bayes factor and the corresponding strength of evidence for the primary end point result in TACT overall, and diabetic cohorts are shown in Table 1. The p-value of 0.035 for TACT overall cohort translates into a Bayes factor of 0.108, which means the evidence supports the null hypothesis ≈1/9th as strongly as it does the alternative. This reduces the null probability from 50% pretrial (justified by suspension of one’s belief in treatment effect) to 10% post-trial. Although this does not represent strong evidence against the null, it does reduce the level of skepticism surrounding chelation therapy. In the diabetic cohort, the nominal p-value of 0.0002 translates into a Bayes factor of 0.002 (1/500), which reduces the extremely skeptical prior null probability of 95% to 4% post- trial, indicating very strong evidence against the null.

In concluding, Dr. Kaul states:

Finally, TACT highlights the double standard when it comes to accepting inconvenient results not aligned with our preconceived notions on so-called dubious quack cures such as chelation…

Closed minds?

Dr. Kaul’s reference “6” above is to a lengthy article that we published in 2008 titled “Why the NIH Trial to Assess Chelation Therapy Should Be Abandoned”. So, it seems, both Drs. Briggs and Kaul were chastising us for our biased, preconceived beliefs about so-called dubious quack cures. Our minds were, apparently, not open. Let’s examine this contention. (more…)

Posted in: Clinical Trials, Health Fraud, Medical Academia, Medical Ethics, Politics and Regulation

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Harkin’s folly, or how forcing insurers to cover CAM undermines the ACA

Bloodletting: a good reason to discard disproven therapies

Bloodletting: a good reason to discard disproven therapies

All of us at SBM have repeatedly expressed frustration at the continuing influx of pseudoscience into the health care system. Judging from comments posted on this site and private communications we receive, our readers share this frustration but are at a loss to figure out how to get through to legislators and other policy makers. Unlike naturopaths and chiropractors, we don’t have the money to hire professional lobbyists. Fortunately, an opportunity to sound off against SCAMs has presented itself, completely free of charge.

How?

Now that the Affordable Care Act enrollment debacle is dying down, the Department of Health and Human Services (HHS) is turning its attention to divining just what the heck Section 2706 of the ACA, the non-discrimination provision, means. (Actually there are other federal agencies involved; to simplify things, here we’ll refer to them collectively as “HHS.”) HHS has opened the issue to public comment, but only until June 10. Let’s take a look at why this is important and what you can do about it.

(There are providers other than chiropractors, naturopaths and acupuncturists involved in this fight. For example, you’ll see public comments from nurse anesthetists and nurse practitioners. But I’m not worried about providers who stick to science.) (more…)

Posted in: Acupuncture, Chiropractic, Legal, Naturopathy, Politics and Regulation, Science and Medicine, Traditional Chinese Medicine, Vaccines

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PETA Embraces Autism Pseudoscience

got-autism-billboardPETA (People for the Ethical Treatment of Animals) has a history of (as the old saying goes) using science as a drunk uses a lamppost – for support rather than illumination. In that way they are typical of ideological groups. They have an agenda, they are very open about their beliefs, and they marshal whatever arguments they can in order to promote their point of view.

Favoring information that supports our current beliefs is a cognitive bias common to Homo sapiens, but ideology tends to take this simple bias to a new level. It can lead to the systematic distortion or denial of science, and render belief systems immune to logic and evidence.

PETA provides us with a nice example of how having an ideological agenda can motivate an individual or a group to embrace dubious science. In an article currently on their website, and making the rounds in social media (this is repeating a claim from at least 2008, but the current article is undated), the group warns: Got Autism? Learn About the Link Between Dairy Products and the Disease. They claim:

The reason why dairy foods may worsen or even cause autism is being debated. Some suspect that casein harms the brain, while others suggest that the gastrointestinal problems so often caused by dairy products cause distress and thus worsen behavior in autistic children.

Saying that “how” dairy harms the brain is being debated implies “that” dairy harms the brain is accepted and not being debated. This is misleading. It is not accepted that dairy harms the brain or is in any way linked to autism, and the evidence is largely against it. (more…)

Posted in: Epidemiology, Nutrition, Science and Medicine

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Rope Worms: C’est la Merde

rope worms

When I first heard about rope worms, I assumed it was a spoof. Alas, not so!

Rope worms are rope-like meter-long human intestinal parasites that were only recently discovered in the returns of cleansing enemas and are often reported after coffee enemas. Strangely, no one had ever noticed them until 2009. They have never been observed during endoscopy or surgery, during medical bowel cleansing in preparation for surgical or imaging procedures, with x-rays or MRIs, at autopsy, or by any colorectal specialists. Yet according to Nikolai Gubarev and Alex Volinsky, the two of them have never yet found a single patient who didn’t have these parasites.

Two articles by Volinsky, Gubarev, and colleagues (here and here) describe the rope worm and its five developmental stages. They include pictures of each stage. I urge you to take a look. You will be amazed, and not in a good way. You might even bust a gut laughing. (more…)

Posted in: Science and Medicine

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In which Dr. Gorski is taken to task by an eminent radiologist for his posts on mammography

40F MLO DMMG

Introduction: An unexpected e-mail arrives

One of the consequences of the growing traffic and prominence of this blog over the last few years is that people who would otherwise have probably ignored what I or my partners in blogging write now sometimes actually take notice. Nearly a decade ago, long before I joined this blog as a founding blogger, if I wrote a post criticizing something that a prominent academic said, it was highly unlikely that that person would even become aware of it, much less bother to respond to whatever my criticism was. I was, quite simply, beneath their notice, sometimes happily, sometimes unhappily.

It appears that those days might be over. Last week Dr. Daniel Kopans, a prominent Harvard radiologist and well-known long-time defender of screening mammography, sent me a rather unhappy e-mail complaining about my “attack” on him on this blog, a charge that he repeated in a subsequent e-mail. Before I publish his initial e-mail verbatim (with his permission), I would like to point out that, while it’s true that I did criticize some of Dr. Kopans’ statements rather harshly in my post about the Canadian National Breast Screening Study (CNBSS), even characterizing one statement as a “howler,” I would hardly characterize what I wrote as an “attack.” That to me tends to imply a personal attack. Using Dr. Kopans’ apparent definition, what he has said and written about investigators like those running the CNBSS, as documented in my post, about H. Gilbert Welch, who published a large study in 2012 estimating the extent of overdiagnosis due to mammography, and the U.S. Preventive Services Task Force (USPSTF), the group that in 2009 suggested changing guidelines for routine screening mammography in asymptomatic women to begin at age 50 instead of age 40, would appear to also qualify as “attacks.”

Be that as it may, I also wondered why Dr. Kopans hadn’t noticed my CNBSS post until more than three months after it had originally appeared. Then, the day after I received Dr. Kopans’ e-mail, my Google Alert on mammography popped up an article in the Wall Street Journal by Dr. Kopans entitled “Mammograms Save Lives: Criticism of breast-cancer screenings is more about rationing than rationality.” That’s when I guessed that someone probably had either posted or e-mailed Dr. Kopans a link to my previous post in response to that article. Given the confluence of events, I think it’s a perfect time to discuss both Dr. Kopans’ e-mail and his article, because they cover many of the same issues. (more…)

Posted in: Cancer, Clinical Trials, Public Health

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Separating Fact from Fiction in Pediatric Medicine: Infant Gastroesophageal Reflux

By now, regular SBM readers should be aware of the Choosing Wisely initiative. Just in case, Choosing Wisely is a campaign developed by the ABIM Foundation to bring together experts from a variety of medical specialties in order to identify common practices that should be questioned by patients and providers, if not outright discontinued. Their ultimate goal was not to establish treatment guidelines or dictate care, but to foster discussion. As I’ve written about in a prior post on the overuse of antibiotics in pediatrics, it doesn’t appear to have caught on. I routinely ask colleagues, residents and students if they are aware of it, and am frequently disappointed by their response.

The American Academy of Pediatrics issued a list of five questionable practices back in February of 2013 and I loved it. All five are important:

  1. Stop treating viruses with antibiotics
  2. Stop prescribing and recommending cough and cold medicines for young children
  3. Stop routine use of CT scans for minor head injuries
  4. Stop routine use of neuroimaging for simple febrile seizures
  5. Stop routine use of CT scans for abdominal pain
  6. (more…)

Posted in: Science and Medicine

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Beware the Integrative Pharmacy

pharmacy window

Imagine a retail pharmacy where some of the medicines on the shelves have been replaced with similar-looking packages that contain no active ingredients at all. There is no easy way to distinguish between the real and the fake.

Another section of the store offers a number of remedies with fantastic claims, such as “boosting” the immune system, “detoxifying” the body, or “cleansing” you of microscopic Candida. They look sciencey, unless you realize that they treat imaginary medical conditions.

A corner of the store offers unpurified drugs supplied as tinctures and teas. The active ingredients aren’t known, and the batch-to-batch consistency of the product is unclear. The store will suggest products for you based on your symptoms.

Walk past the enormous wall of vitamins and other supplements and you’ll find a nutritionist who will tell you what products you should be taking. You’ll also find a weight loss section. From a science-based perspective, this shouldn’t even exist, given no product has been shown to offer any meaningful benefit. But there are dozens of products for sale.

At the back of the store you’ll finally find the pharmacist. A sign on the counter offers blood- and saliva-based tests for food “intolerance” and adrenal “fatigue”, claiming to test for medical conditions that actually don’t exist or lack an evidence base. The pharmacy also offers a large compounding practice, advertising what it calls “personalized” approaches to hormone replacement with “bioidentical” hormones.

Welcome to the “integrative” pharmacy.

You may not see all these features in your local drug store, but they’re coming: claims of a new “integrative” way to provide health care that is changing the face of retail pharmacy. Unfortunately, it’s harkening back to the era of patent medicines and snake oil. It’s not good for the pharmacists and the profession of pharmacy, and it’s even worse for patients. (more…)

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

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Vaccines Still Not Linked to Autism

Myths tend to be persistent and require periodic maintenance debunking. The anti-vaccine movement arguably can credit its recent increase in effect to successfully spreading fears that vaccines in general, and particularly either the MMR vaccine (mumps, measles, and rubella) or the vaccine preservative thimerosal, are linked to autism. This claim was never based on legitimate science, and over the last 15 years has been overwhelmingly repudiated by multiple independent lines of scientific evidence.

It is easier to spread fears than it is to reassure anxious parents with abstract scientific data, but still we must try. It also seems that giving people information is not an effective way to change their opinions or their behavior. But at the very least I hope to better inform those who are already on board with the science-based approach, and perhaps we can reach the occasional person on the fence who is simply misinformed and open to changing their mind.

A new meta-analysis seems like a good opportunity to remind the public that vaccines are safe and effective, and that they are not linked to neurodevelopmental disorders. The study is: “Vaccines are not associated with autism: An evidence-based meta-analysis of case-control and cohort studies,” by Taylor, Swerdfeger and Eslick, is published in the journal Vaccine. They found: (more…)

Posted in: Vaccines

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Precision Medicine: The Coolest Part of Medicine

QuellosOne size rarely fits all. Most medical knowledge is derived from studying groups of subjects, subjects who may be different in some way from the individual who walks into the doctor’s office. Basing medicine only on randomized controlled studies can lead to over-simplified “cookbook” medicine. A good clinician interprets study results and puts them into context, considering the whole patient and using clinical judgment to apply current scientific knowledge appropriately to the individual.

CAM practitioners claim to be providing individualized treatments. Homeopaths look up symptoms like “dreams of robbers,” “sensation of coldness in the heart,” and “chills between 9 and 11 AM” in their books, and naturopaths quiz patients in great depth about their habits and preferences; but they don’t have a plausible rationale for interpreting the information they gather. And they have not been able to demonstrate better patient outcomes from using that information.

A new concept, “precision medicine,” was recently featured in UW Medicine, the alumni magazine of my alma mater, the University of Washington School of Medicine. Precision medicine strives to provide truly individualized care based on good science. It identifies the individual variations in people that make a difference in our ability to diagnose and treat accurately. Peter Byers, MD, director of the new Center for Precision Diagnostics at the University of Washington, calls it “the coolest part of medicine.” (more…)

Posted in: Basic Science, Cancer, Technology

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What’s in a name?: NCCAM tries to polish a turd

turdpolish

What’s in a name? that which we call a rose
By any other name would smell as sweet;
So Romeo would, were he not Romeo call’d,
Retain that dear perfection which he owes
Without that title. Romeo, doff thy name,
And for that name which is no part of thee
Take all myself.

William Shakespeare, Romeo and Juliet, Act II, Scene 2

You can clean up a pig, put a ribbon on its tail, spray it with perfume, but it is still a pig.

You can paint a turd red, but it’s still a turd.

There’s a colloquial phrase commonly used to describe an effort to sell or promote something that is so inherently awful or at least so flawed as to be unsalvageable without either a radical rethinking or such a major overhaul that it would be impractical or impossible to do: Polishing a turd. In this, advocates of so-called “complementary and alternative medicine” (CAM) have been very successful. Mark Crislip, in his usual inimitable fashion, just reminded us why CAM is a turd that needs polishing. Unfortunately, on Friday, I learned that the National Center for Complementary and Alternative Medicine unveiled a proposal to help it be more efficient in polishing the turd that is CAM through the clever use of language, and it wants your feedback. There were lots of other things that happened over the last few days that tempted me to write about them that will likely have to appear over at my not-so-secret other blog, but this one caught my attention and held it, given that it goes to the very heart of the deceptive use of language that is at the heart of giving CAM the appearance of legitimacy. In this specific case, NCCAM wants a new name. Dr. Briggs wants to rename NCCAM the National Center for Research on Complementary and Integrative Health (NCRCI). (I have no idea why the abbreviation of the proposed new center name isn’t NCRCIH.) Here’s Dr. Briggs explaining the rationale for the proposal and urging feedback by June 6 at http://nccam.nih.gov/about/offices/od/comments. I urge you to watch the whole video, or at least read the transcript:

Thus does Dr. Briggs propose polishing the turd that is NCCAM.
(more…)

Posted in: Clinical Trials, Medical Academia, Politics and Regulation

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