Author Archive

Vertebroplasty for compression fractures due to osteoporosis: Placebo medicine

If there’s one thing we emphasize here on the Science-Based Medicine blog, it’s that the best medical care is based on science. In other words, we are far more for science-based medicine, than we are against against so-called “complementary and alternative medicine” (CAM). My perspective on the issue is that treatments not based on science need to be either subjected to scientific scrutiny if they have sufficient prior plausibility or strong clinical data suggesting efficacy or abandoned if they do not.

Unfortunately, even though the proportion of medical therapies not based on science is far lower than CAM advocates would like you to believe, there are still more treatments in “conventional” medicine that are insufficiently based on science or that have never been validated by proper randomized clinical trials than we as practitioners of science-based medicine would like. This is true for some because there are simply too few patients with a given disease; i.e., the disease is rare. Indeed, for some diseases, there will never be a definitive trial because they are just too uncommon. For others, it’s because of what I like to call medical fads, whereby a treatment appears effective anecdotally or in small uncontrolled trials and, due to the bandwagon effect, becomes widely adopted. Sometimes there is a financial incentive for such treatments to persist; sometimes it’s habit. Indeed, there’s an old saying that, for a treatment truly to disappear, the older generation of physicians has to retire or die off.

That is why I consider it worthwhile to write about a treatment that appears to be on the way to disappearing. At least, I hope that’s what’s going on. It’s also a cautionary tale about how the very same sorts of factors, such as placebo effects, reliance on anecdotal evidence, and regression to the mean, can bedevil those of us dedicated to SBM just as much as it does the investigation of CAM. It should serve as a warning to those of us who might feel a bit too smug about just how dedicated to SBM modern medicine is. Given that the technique in question is an invasive (although not a surgical technique), I also feel that it is my duty as the resident surgeon on SBM to tackle this topic. On the other hand, this case also demonstrates how SBM is, like the science upon which it is based, self-correcting. The question is: What will physicians do with the most recent information from very recently reported clinical trials that clearly show a very favored and lucrative treatment does not work better than a placebo?

Here’s the story that illustrates these issues, fresh from the New York Times this week:

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

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Dr. Joe Albietz joins SBM!

One month ago, I was honored to take part not just in the Science-Based Medicine Conference at TAM 7 in Las Vegas but to be a part of the Anti-Anti-Vax Panel. I was even more honored to be on the same panel as Dr. Joe Albietz, a pediatric intensivist from the University of Colorado who organized a fund-raising drive to benefit the Southern Nevada Health District and contribute to the vaccination of children in a region where the vaccination rate is, unfortunately, low. I’m even more pleased that Dr. Albietz has agreed to join SBM as a regular blogger. Here’s a little bit about Joe:

Joseph Albietz, M.D. is an Assistant Professor of Pediatrics at the University of Colorado, Denver, and The Children’s Hospital. In addition to his service in the Pediatric Intensive Care Unit, his time is divided between translational research in the field of pediatric pulmonary hypertension and medical education where he acts as the pediatric intensive care associate fellowship director. Dr. Albietz graduated from the University of Missouri at Kansas City and completed his residency training in pediatrics and a fellowship in pediatric critical care at the University of Colorado, Denver. He is board certified in Pediatrics and Pediatric Critical Care.

In addition to writing for Science Based Medicine Dr. Albietz also periodically contributes to the James Randi Educational Foundation’s (JREF) Swift Blog and coordinated JREF’s vaccine drive to benefit the Southern Nevada Health District.

Dr. Albietz’s first blog post is scheduled for Friday, August 21. In the meantime, please welcome him to the fold. He’s a great addition to our crew of bloggers.

Posted in: Announcements

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Senator Tom Harkin and Representative Darrell Issa declare war on science-based medicine

In discussions of that bastion of what Harriet Hall likes to call “tooth fairy science,” where sometimes rigorous science, sometimes not, is applied to the study of hypotheses that are utterly implausible and incredible from a basic science standpoint (such as homeopathy or reiki), the National Center of Complementary and Alternative Medicine (NCCAM), I’ve often taken Senator Tom Harkin (D-IA) to task, as have Drs. Novella, Lipson, and Atwood. That’s because Senator Harkin is undeniably the father of that misbegotten beast that has sucked down over $2.5 billion of taxpayer money with nothing to show for it. NCCAM is the brainchild of Senator Harkin, who foisted it upon the National Institutes of Health not because there was a scientific need for it or because scientists and physicians cried out for it but rather because Senator Harkin, who believed that alternative medicine had healed a friend of his, wanted it, and he used his powerful position to make it happen, first as the Office of Unconventional Therapies, then as the Office of Alternative Medicine, and finally as the behemoth of woo that we know today as NCCAM. The result has included a $30 million trial of chelation therapy in which convicted felons were listed among the investigators and a totally unethical trial of the Gonzalez therapy for pancreatic cancer. It’s not for naught that Wally Sampson called for the defunding of NCCAM, as have I and others. Not surprisingly, alternative medicine practitioners are appalled at this idea.

Most recently, Harkin has been most disturbed by the observation that NCCAM’s trials have all been negative, going so far as to complain that NCCAM hasn’t produced any positive results showing that various alternative therapies actually work. This is, of course, not a surprise, given that vast majority of the grab bag of unrelated (and sometimes theoretically mutually exclusive) therapies are based on pseudoscience. One of the only exceptions is the study of herbal remedies, which is a perfectly respectable branch of pharmacology known as pharmacognosy. Unfortunately, as David Kroll showed, in NCCAM the legitimate science of pharmacognosy has been hijacked for purposes of woo. Meanwhile, earlier this year, Senator Harkin hosted a hearing in which Drs. Dean Ornish, Andrew Weil, Mehment Oz, and Mark Hyman (he of “functional medicine“) were invited to testify in front of the Senate. Add to that other powerful legislators, such as Representative Dan Burton (R-IN), trying to craft legislation in line with his anti-vaccine views and pressure the NIH to study various discredited hypotheses about vaccines and autism. Clearly, when it comes to quackery, there are powerful legislative forces promoting pseudoscience and studies driven by ideology rather than science.

Posted in: Acupuncture, Chiropractic, Homeopathy, Politics and Regulation, Science and Medicine

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Are one in three breast cancers really overdiagnosed and overtreated?

ResearchBlogging.orgScreening for disease is a real pain. I was reminded of this by the publication of a study in BMJ the very day of the Science-Based Medicine Conference a week and a half ago. Unfortunately, between The Amaz!ng Meeting and other activities, I was too busy to give this study the attention it deserved last Monday. Given the media coverage of the study, which in essence tried to paint mammography screening for breast cancer as being either useless or doing more harm than good, I thought it was imperative for me still to write about it. Better late than never, and I was further prodded by an article that was published late last week in the New York Times about screening for cancer.

If there’s one aspect of medicine that causes more confusion among the public and even among physicians, I’d be hard-pressed to come up with one more contentious than screening for disease, be it cancer, heart disease, or whatever. The reason is that any screening test is by definition looking for disease in an asymptomatic population, which is very different from looking for a cause of a patient’s symptoms. In the latter case, the patient is already being troubled by something that is bothering him. There may or may not be a cause in the form of a disease or syndrome that is responsible for the symptoms, but the very existence of the symptoms clues the physician in that there may be something going on that requires treatment. The doctor can then narrow down range of possibilities for what may be the cause of the patient’s symptoms by taking a careful history and physical examination (which will by themselves most often lead to the diagnosis). Diagnostic tests, be they blood tests, X-rays, or other tests, then tend to be more confirmatory of the suspected diagnosis than the main evidence supporting a diagnosis.

Posted in: Cancer, Clinical Trials, Public Health, Science and Medicine, Science and the Media

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The clinician-scientist: Wearing two hats

About a week ago, Tim Kreider wrote an excellent post about the differences between medical school training and scientific training. As the only other denizen of Science-Based Medicine who has experienced both worlds, that of a PhD and that of an MD, and as the one who two decades further along the path than Tim (give or take a couple of years), his musings reminded me of similar musings I’ve had over the years, as well as emphasizing yet again something I’ve said time and time again: Most physicians are not scientists. They are not trained like scientists; they are trained to apply scientific knowledge to the care of their patients. That’s what science-based medicine is, after all, applying science to the care of patients. Not dogma. Not tradition. Not knowledge of antiquity. Science.

Leave dogma, tradition, and “ancient knowledge” to practitioners of “alternative medicine.” That’s where they all belong. Whether you want to call it “alternative medicine,” “complementary and alternative medicine” (CAM), or “integrative” medicine (IM), it rarely changes and almost never abandons therapies that science finds to be no better than placebo, whereas scientific medicine is, as it should be, ever changing, ever improving. I’ll grant you that the process is often messy. There are often false starts and blind alleys, and physicians are all too often reluctant to change their practices in response to the latest scientific findings. We sometimes even joke that for some practices, it takes the supplanting of one generation of physicians with a new generation to get rid of some practices. But change does come when the science and evidence are there. Indeed, for example, in response to evidence that a bacterium, H. pylori, causes duodenal ulcers, medical practice changed in a mere decade, which is about as fast as anyone could do the science and clinical trials to show the validity of the new concept. Although CAM practitioners like to hold up the example of Barry Marshall and Robin Warren, the researchers who discovered that H. pylori causes most duodenal ulcers, as an example of how researchers with radical ideas are ostracized, but that story is largely a myth, as our very own Kim Atwood showed.

The application of science to medicine is a difficult thing. It takes basic scientists and clinicians, but the two of them exist in different worlds. Or so it often seems. That’s why some individuals seek to straddle both worlds. Tim is one such person. So am I. Unfortunately, most people don’t understand what we do very well. We wear two hats. In my case, I’m a surgeon, and I’m a scientist. In Tim’s case, he’s a scientist and a physician, but he doesn’t yet know what kind of physician he will end up being. At the risk of sounding somewhat arrogant, I believe that we, and others like us, represent an important element in bridging the gap between basic science and clinical science, in, essentially, building a more science-based medicine.

Posted in: Basic Science, Clinical Trials, Medical Academia

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Does popularity lead to unreliability in scientific research?

One of the major themes here on the Science-Based Medicine (SBM) blog has been about one major shortcoming of the more commonly used evidence-based medicine paradigm (EBM) that has been in ascendance as the preferred method of evaluating clinical evidence. Specifically, as Kim Atwood (1, 2, 3, 4, 5, 6, 7, 8) has pointed out before, EBM values clinical studies above all else and devalues plausibility based on well-established basic science as one of the “lower” forms of evidence. While this sounds quite reasonable on the surface (after all, what we as physicians really want to know is whether a treatment works better than a placebo or not), it ignores one very important problem with clinical trials, namely that prior scientific probability matters. Indeed, four years ago, John Ioannidis made a bit of a splash with a paper published in JAMA entitled Contradicted and Initially Stronger Effects in Highly Cited Clinical Research and, more provocatively in PLoS Medicine, Why Most Published Research Findings Are Wrong. In his study, he examined a panel of highly cited clinical trials and determined that the results of many of them were not replicated and validated in subsequent studies. His conclusion was that a significant proportion, perhaps most, of the results of clinical trials turn out not to be true after further replication and that the likelihood of such incorrect results increases with increasing improbability of the hypothesis being tested.

Not surprisingly, CAM advocates piled onto these studies as “evidence” that clinical research is hopelessly flawed and biased, but that is not the correct interpretation. Basically, as Steve Novella and, especially, Alex Tabarrok pointed out, prior probability is critical. What Ioannidis’ research shows is that clinical trials examining highly improbable hypotheses are far more likely to produce false positive results than clinical trials examining hypotheses with a stronger basis in science. Of course, estimating prior probability can be tricky based on science. After all, if we could tell beforehand which modalities would work and which didn’t we wouldn’t need to do clinical trials, but there are modalities for which we can estimate the prior probability as being very close to zero. Not surprisingly (at least to readers of this blog), these modalities tend to be “alternative medicine” modalities. Indeed, the purest test of this phenomenon is homeopathy, which is nothing more than pure placebo, mainly because it is water. Of course, another principle that applies to clinical trials is that smaller, more preliminary studies often yield seemingly positive results that fail to hold up with repetition in larger, more rigorously designed randomized, double-blind clinical trials.

Last week, a paper was published in PLoS ONE Thomas by Thomas Pfeiffer at Harvard University and Robert Hoffmann at MIT that brings up another factor that may affect the reliability of research. Oddly enough, it is somewhat counterintuitive. Specifically, Pfeiffer and Hoffmann’s study was entitled Large-Scale Assessment of the Effect of Popularity on the Reliability of Research. In other words, the hypothesis being tested is whether the reliability of findings published in the scientific literature decreases with the popularity of a research field. Although this phenomenon is hypothesized based on theoretical reasoning, Pfeiffer and Hoffmann claim to present the first empirical evidence to support this hypothesis.

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

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Homeopathic A & E

I love the British comedy duo Mitchell and Webb, and this is just one reason why. They totally get homeopathy, as this video e-mailed to me by a reader demonstrates:

Pay close attention to the signs in the A & E.

No doubt Dana Ullman will show up to cry foul over how Mitchell and Webb are totally “misrepresenting” homeopathy…

Posted in: Homeopathy, Humor

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Cancer research: Going for the bunt versus swinging for the fences

A couple of weeks ago, our resident skeptical medical student Tim Kreider wrote an excellent article about an op-ed in NEWSWEEK by science correspondent Sharon Begley, in which he pointed out many misconceptions she had regarding basic science versus translational research, journal impact factors, and how journals actually determine what they will publish. Basically, her thesis rested on little more than a few anecdotes by scientists who didn’t get funded or published in journals with as high an impact factor as they thought they deserved, with no data, science, or statistics to tell us whether the scientists featured in her article were in fact representative of the general situation. Begley’s article caught flak from others, including Mike the Mad Biologist and our very own Steve Novella. Naturally, as the resident cancer surgeon and researcher, I had thought of weighing in, but other issues interested me more at the time.

In retrospect, I rather regret it, given that this issue crops up time and time again. In essence, it’s a variant of the lament that pops up in the press periodically, when science journalists look at survival rates for various cancers and ask why, after nearly 40 years, we haven’t yet won the war on cancer. Because of his youth, Tim probably hasn’t seen this issue crop up before, but, trust me, every couple of years or so it does. Begley’s article and the NYT article strike me as simply “Why are we losing the war on cancer?” 2009 edition.

Now the New York Times has given me an excuse both to revisit Begley’s article and discuss yesterday’s front page article in the NYT Grant System Leads Cancer Researchers to Play It Safe. Basically, they are variants of the same complaints I’ve heard time and time again. Now, don’t get me wrong. By no means am I saying that the current system that the NIH uses to determine which scientists get funded. Those who complain that the system is often too conservative have a point. The problem, all too often, however, is that the proposals for how to fix the problem are usually either never spelled out or rest on dubious assumptions about the nature of cancer research themselves.

Posted in: Basic Science, Cancer, Medical Academia, Politics and Regulation

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