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.
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.
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…)
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…)
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.
The Cultural Revolution
After investigating ‘acupuncture anesthesia’ in the People’s Republic of China in 1973, John Bonica wrote:
From the guarded comments made by several anesthesiologists, I concluded that this disuse [of ‘acupuncture anesthesia,’ after its introduction in 1958 until the Great Proletarian Cultural Revolution began in 1966] was the result of disappointing failures in a significant proportion of patients. During the Cultural Revolution this “negative” trend of not using acupuncture was considered the work of revisionists, and subsequently greater emphasis was given to the widespread use of acupuncture in all hospitals.
Similarly, according to Petr Skrabanek,
Those who dared ask such awkward questions [about ‘acupuncture anesthesia’] were branded as “counter-revolutionary revisionists.”
Skrabanek’s reference for that assertion was this 37-page pamphlet:
An Original: Richard De Mille, Carlos Castaneda, and Literary Quackery
I was away in Nature – with a real capital N, and decided to insert an allegory this week instead of a medical subject. The genesis here was a sweeping of the mind and brushing away of cobwebs and detritus called worries and other preoccupations. The application to this here blog is – methodology. The experience is one of discovery, and of loss, and of bearing the burden of inaction.
Some thirty or more years ago a family member became enamored of a new book, The Teachings of don Juan by an unknown author, Carlos Castaneda. But mention the name now and one gets one of two responses: Who is that? Or, Oh, he is that literary fraud. But in the late 1960s – 1970s, two social movements had captured imaginations of youth, academics, and much of the intellectual world. They made fantasy seem plausible, and fraud seem believable – psychedelics and postmodernism.
Advocates of psychedelics, most of whom experienced drug-induced alterations, promoted revolutionary psychological ideas such as drug-induced multiple realities. The other, postmodernism, was and is the intellectual and philosophical movement originating in academia that similarly views of reality(ies) as possibly multiple. (The relation, if any, to alternate universes and relativity theories in physics I have to leave to philosophers.) But the ‘60s and ‘70s were decades of several revolutions in social and personal thought – paradigm changes – that brought fairy tales, delusions, and irrationality onto realms of plausibility, from which we are still reeling, and trying to deal with.
One of the common themes in biology and medicine is the feeling that somehow there must be more. Creationist cults simply know that life must be more than matter, and mind-body dualists (which includes most alternative medicine advocates) are certain that humans are more than an “ugly bag of mostly water” (sorry for the geek reference). If you can stick with me here, I’ll explain to you a bit of the history surrounding this fallacy.
Most of us intuitively feel that we are both a body and a person. In every day life, it makes a certain operational sense to think of our “mind” as being something distinct. From a biological standpoint, however, this doesn’t work as well.
Biology was one of the last of the “natural philosophies” to become a science. It was clear to those who studied chemistry and physics that certain principles seemed to explain the natural world, but those who studied living things were mostly involved in description. Still, biology has become a science in its own right. According to Ernst Mayr, one of the greatest biologists of the last century, a number of events preceded biology being recognized as a legitimate science. One vital event was the recognition that all biological processes were constrained by the laws of physics and chemistry. Another important step was the rejection of two erroneous principles: vitalism, and teleology. (more…)
When patients ask me if a chiropractor can help them with their problem, I often think to myself, “OK, do I give them the short answer or the long answer?” The difficulty is often in the fact that chiropractic is a diverse profession and it is difficult to even characterize what a “typical” chiropractor is likely to do. As a chiropractor once admitted to me – there are a great many things that happen under the umbrella of “chiropractic.”
In this article I will summarize some of the history and practice of chiropractic, highlighting what I consider to be many of the enduring problems with this profession.
Chiropractic was founded in 1895 by Daniel David Palmer, a grocer with an intense interest in metaphysics. Prior to his “discovery” of chiropractic, D.D. Palmer was a magnetic healer. He also had interests in phrenology (diagnosing disease based on the bumps of the skull) and spiritualism. Palmer reported to have discovered the principle of chiropractic when he allegedly cured a janitor of his deafness by manipulating his neck. The fact that the nerve which conveys sound information from the ears to the brain does not pass through the neck did not seem to bother Palmer, if he was even aware of this fact.
Palmer created the term “chiropractic,” which literally means “done by hand,” to refer to his new therapy. He argued that all disease is caused by subluxated bones, which 95% of the time are spinal bones, and which disrupt the flow of innate intelligence. He did not subject his ideas to any form of research, but rather went directly to treating patients and to teaching his principles to the first generation of chiropractors.
In May 2008, the article “Why the NIH Trial to Assess Chelation Therapy (TACT) Should Be Abandoned” was published online in the Medscape Journal of Medicine. The authors included two of our own SBM bloggers, Kimball Atwood and Wallace Sampson, along with Elizabeth Woeckner and Robert Baratz. It showed that the existing evidence on treating heart disease with IV chelation did not justify further study, and that the TACT trial was questionable on several ethical points. Their ethical concerns were taken seriously enough that enrollment in the trial was put on hold pending an investigation. It has now been re-opened after a few band-aids were applied to the ethical concerns. The scientific concerns were never addressed.
I have seen many critiques of the Atwood study, and not a single one has offered any cogent criticism of its factual content or reasoning. Most of them could have been written by someone who had not bothered to read beyond the title. Their arguments can be boiled down to a few puerile points that can be further simplified to:
(1) I believe the testimonial evidence that chelation works.
(2) Atwood and his co-authors are bad guys.
Now Beth Clay has chimed in with an article entitled “Study of Chelation Therapy Should Not Be Abandoned.” I found it truly painful to read, but even the worst has some value as a bad example. Clay’s article could be used for a game of “Count the Errors.” I will point out some of them below. (more…)
Last week, I wrote one of my characteristically logorrheic meandering posts about what turns a scientist into a crank or a doctor into a quack. In a sort of continuation of this line of thinking, this week I’ll turn my attention to one of the other most common characteristics of a crank, be he scientific crank (i.e., a creationist), a quack, or historical crank (i.e., Holocaust deniers), specifically how he views the peer review system.
Not suprisingly, one of the favorite targets of pseudoscientists is, in fact, the peer review system. Indeed, it’s a very safe thing to say that, almost without exception, cranks really, really, really don’t like the peer review system for scientific journals and grant review. After all, it’s the system through which scientists submit their manuscripts describing their scientific findings or their grant proposals to their peers, and their peers make a judgment whether manuscripts are scientifically meritorious enough to be published and grant applications scientifically compelling enough to be funded. Creationists hate peer review. HIV/AIDS denialists hate it. Anti-vaccine cranks like those at Age of Autism hate it. Indeed, as a friend of mine, Mark Hoofnagle pointed out a couple of years ago, pseudoscientists and cranks of all stripes hate it. There’s a reason for that, of course, namely that vigorous peer review is a major part of science that keeps pseudoscientists from attaining the respectability that science possesses and that they crave so.