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Healing Touch and Coronary Bypass

A study published in Alternative Therapies in Health and Medicine is being cited as evidence for the efficacy of healing touch (HT). It enrolled 237 subjects who were scheduled for coronary bypass, randomized them to receive HT, a visitor, or no treatment; and found that HT was associated with a greater decrease in anxiety and shorter hospital stays.

This study is a good example of what I have called “Tooth Fairy Science.” You can study how much money the Tooth Fairy leaves in different situations (first vs. last tooth, age of child, tooth in baggie vs. tooth wrapped in Kleenex, etc.), and your results can be replicable and statistically significant, and you can think you have learned something about the Tooth Fairy; but your results don’t mean what you think they do because you didn’t stop to find out whether the Tooth Fairy was real or whether some more mundane explanation (parents) might account for the phenomenon. (more…)

Posted in: Clinical Trials, Energy Medicine

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

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Medical training versus scientific training

This month I will begin my third year of medical school, after a three-year break for laboratory research. Living alternately in the worlds of med school and grad school has prompted me to reflect on differences between these training programs.

[Obvious disclaimer: I have studied at a single institution, and only for five years.]

I am enrolled in a dual-degree MD/PhD program. About 120 US medical schools have such programs, and the National Institutes of Health funds a third of them (MSTP). The schedule of such programs is generally: 2 years of medical school (culminating in USMLE Step 1), 3+ years of graduate school (culminating in dissertation and PhD), and then the last 2 years of medical school (which I begin this month). The most popular residency choices for MD/PhD graduates are internal medicine, pediatrics, and pathology (match data). Other residencies that attract these graduates include dermatology, neurology, ophthamology, and radiology (survey data). The hopes of those funding the MD/PhD training programs and of those accepting the graduates is that these individuals will become physician-scientists, bridging the divide between lab bench and patient bedside with insights from both. (more…)

Posted in: Medical Academia, 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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The Evil League of Evil is Nothing in Comparison

Transcribed minutes of a meeting, provenance unknown.

Chairman: “I would like to call this emergency meeting to order and thank you all for coming under short notice.  If there are no objections, I will dispense with the usual formalities and get right to the business at hand.”

Murmur of approval.

Chairman: Ladies, Gentleman and Demons of all kinds, we have been, to use the vernacular of the day, outed.”

Murmur of consternation

Voice from the crowd: “I am most certainly not gay.”

Chairman: “Not gay.  We have been outed as a society. The Evil Society of the Evil Medical Industrial Complex, our beloved ESEMIC,  is no longer secret.  Our works have been discovered.  The true meaning of the Caduceus has been published for all to see.  And by your fruits you shall be known.  Sorry demons”

Louder murmur of consternation.

Loud voice from the crowd: “I demand to know how this occurred.  This is impossible.”

Shouts of agreement.

Chairman:  “If you will please all remain calm, I will explain.”

Pause.
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Posted in: Humor

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Could Francis Collins’ Faith Create Conflicts For His Potential Directorship of NIH?

Francis Collins, M.D., Ph.D., is probably best known for his leadership of the Human Genome Project, though his discoveries of the Cystic Fibrosis, Huntington’s, and Neurofibromatosis genes are also extraordinary accomplishments. Dr. Collins is a world-renowned scientist and geneticist, and also a committed Christian. In his recent best-selling book, The Language Of God, Dr. Collins attempts to harmonize his commitment to both science and religion.

Some critics (such as Richard Dawkins) have expressed reservations about Dr. Collins’ faith, wondering if it might cloud his scientific judgment. Since Collins is rumored to be the most likely candidate for directorship of the NIH, and because I wanted to know if Dawkins et al. had any reason for concern, I decided to read The Language Of God.

First of all, Christians are a rather heterogeneous group – with a range of viewpoints on evolution, science, and the interpretation of Biblical texts. On one extreme there are Christians (often referred to as “young earth creationists” or simply “creationists”) who believe in an absolutely literal interpretation of the Genesis story, and see evolution as antithetical to true faith. Dr. Collins suggests that as many as 45% of Christians may actually be in this camp.
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Posted in: Basic Science, Book & movie reviews, Evolution

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Human Subjects as Political Pawns

When it comes to “alternative medicine” trials, it seems that the NIH is willing to experiment on people in ways that would be unthinkable for real biomedical research. The federal Office for Human Research Protections (OHRP) has posted a preliminary determination letter, dated May 27, 2009, addressing some of the charges we had made against the politics-driven NIH Trial to Assess Chelation Therapy (TACT).

It is a remarkably damning statement, particularly regarding an NIH study. That is, it found—or the recipients admitted—that each of several charges was valid. Among these are misleading statements and unstated risks in the consent form, and the embarrassing backgrounds of TACT investigators. According to the determination letter,

…investigations revealed multiple instances of substandard practices, insurance fraud, and felony activity on the part of investigators.”

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Posted in: Politics and Regulation, Science and Medicine

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Chiropractic – A Brief Overview, Part II

Last week I reviewed the history of chiropractic and discussed issues relating to its underlying claims and treatments for non-musculoskeletal indications. Today I will focus on chiropractic for back pain and similar indications.

Manipulative Therapy

There is evidence to support the very narrow indication of spinal manipulation for the symptomatic management of acute uncomplicated lower back strain. The good news for chiropractors is that this is a very common condition and does not respond well to conventional management – actually all treatments: medical management, physical therapy, manipulation, and even just patient education, appear to be equally and quite modestly effective.

There is a body of clinical studies that are relevant to the question of manipulation for lower back strain. A review of this research was published in 1989 by the RAND corporation, an independent research group that put together a panel of both physicians and chiropractors to review the available research on manipulative therapy. They concluded that evidence from 22 studies supported the use of manipulative therapy for acute uncomplicated lower back pain (again – no real pinched nerves). It is important to understand, however, that they were referring to manipulative therapy, not chiropractic. In fact only 4 of the 22 studies mentioned included chiropractors. In the other studies the manipulative therapy was performed by physicians and physical therapists.

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Posted in: Chiropractic

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I get mail–chiroquacktic edition

A long while back, at the original wordpress incarnation of my usual blog, I wrote a piece on the reasons that chiropractic is unscientific nonsense. Because it was popular, I resurrected it. Well, a chiropractor has come to bravely defend his field and left me a comment.

A study in the May 2007 issue of the Journal of Manipulative and Physiological Therapeutics reports health plans that use Chiropractors as Primary Care Providers (PCPs) reduce their health care utilization costs significantly.

The study covers the seven-year period from 1999 to 2005. Researchers compared costs and utilization data from an Independent Physicians Association (IPA) that uses Chiropractors as PCPs and a traditional HMO that doesn’t.

The Chiropractic PCPs had 59 percent fewer hospitalizations, 62 percent fewer outpatient surgical cases and 85 percent lower drug costs compared with the HMO plans.

The patients in the Chiropractic PCP group also reported higher satisfaction with their care than the HMO group. Over the seven-year period, Chiropractic patients consistently demonstrated a high degree of satisfaction with their care that ranged from 89 percent to 100 percent.

Study co-author James Winterstein, D.C. says that patients using Chiropractic PCP health care groups “experienced fewer hospitalizations, underwent fewer surgeries and used considerably fewer pharmaceuticals than HMO patients who received traditional medical care.”

Hmmm…interesting assertions. Let’s examine these assertions and the “article” they come from. (more…)

Posted in: Science and Medicine

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Screening Tests – Cumulative Incidence of False Positives

It’s easy to think of medical tests as black and white. If the test is positive, you have the disease; if it’s negative, you don’t. Even good clinicians sometimes fall into that trap. Based on the pre-test probability of the disease, a positive test result only increases the probability by a variable amount. An example: if the probability that a patient has a pulmonary embolus (based on symptoms and physical findings) is 10% and you do a D-dimer test, a positive result raises the probability of PE to 17% and a negative result lowers it to 0.2%.

Even something as simple as a throat culture for strep throat can be misleading. It’s possible to have a positive culture because you happen to be an asymptomatic strep carrier, while your current symptoms of fever and sore throat are actually due to a virus. Not to mention all the things that might have gone wrong in the lab: a mix-up of specimens, contamination, inaccurate recording…

Mammography is widely used to screen for breast cancer. Most patients and even some doctors think that if you have a positive mammogram you almost certainly have breast cancer. Not true. A positive result actually means the patient has about a 10% chance of cancer. 9 out of 10 positives are false positives.

But women don’t just get one mammogram. They get them every year or two. After 3 mammograms, 18% of women will have had a false positive. After ten exams, the rate rises to 49.1%. In a study of 2400 women who had an average of 4 mammograms over a 10 year period, the false positive tests led to 870 outpatient appointments, 539 diagnostic mammograms, 186 ultrasound examinations, 188 biopsies, and 1 hospitalization. There are also concerns about changes in behavior and psychological wellbeing following false positives.

Until recently, no one had looked at the cumulative incidence of false positives from other cancer screening tests. A new study in the Annals of Family Medicine has done just that. (more…)

Posted in: Clinical Trials, Diagnostic tests & procedures

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