Tuesday, July 14, 2009

Science-based medicine conference, part 3: chiropractic

This is part three of my summary of the Science-Based Medicine conference at TAM7, which will be followed by a summary of TAM7 itself. Part one, Dr. Steven Novella's introduction, is here. Part two, Dr. David Gorski on cancer quackery, is here.

The next session was Dr. Harriet A. Hall, the "SkepDoc," a retired family physician and former Air Force flight surgeon, on "A Scientific Critique of Chiropractic."

Dr. Hall began her talk by observing that 10% of Americans see a chiropractor some time each year, and said that her talk would address the questions of when you should see a chiropractor, what they really do, is it based on science, and why isn't it part of regular medicine.

Chiropractic, she said, is a pre-scientific system that was discovered on a single day (September 18, 1895) by D. D. Palmer, a grocer and magnetic healer. On that day, he performed a spinal manipulation on a deaf janitor and allegedly cured his hearing, and based on that single case, claimed that he had found the cause of all disease. Hall noted that in 1895, Pasteur had just died, X-rays had just been discovered, and the germ theory of disease was just catching on. For perspective, she noted that 1900 was the first year in which you would have a 50% chance of having a beneficial outcome from a visit to a doctor.

Chiropractic theory says that all disease is caused by subluxations, or dislocated joints, causing nerve impairment, thereby impacting the flow of "Innate," a mystical force that flows through us. There are real subluxations, which are visible on X-rays, but chiropractic subluxations have never been demonstrated to exist. The chiropractic finding of "Boop"--bone out-of-place--can't be documented on X-rays, and chiropractors have claimed that they are as small as 1/10,000,000 mm.

The current chiropractic definition of subluxation (as defined by the American Association of Chiropractic Colleges) has been adjusted to be more vague: "a complex of functional and/or structural and/or pathological articular changes that compromise neural integrity and may influence organ system and general health."

Palmer said that 95% of ill health and disease is caused by spinal subluxations, and 5% from misalignments of other bones. Hall suggested that if this were true, invertebrates wouldn't get sick, though perhaps chiropractors would say that Palmer was only speaking of the causes in humans. She went on to point out that a ruptured disc is an example of a spinal injury which causes pain without subluxation, directly refuting Palmer's claim.

The chiropractic theory of nerve impingement often uses a garden hose analogy, that a kink in the hose causes water to back up on one side of the kink. But this analogy is not correct, because nerve conduction speed is only affected at the point of compression, as seen in carpal tunnel syndrome. While such nerve dysfunctions do exist, they don't work the way chiropractic says, and they are not the cause of most disease.

A further problem for chiropractic is that 12 cranial nerves and 5 sacral nerves are out of reach for chiropractic manipulation.

Hall showed a diagram about the flow of "Innate" which showed the doctor's "Innate" influencing the patient's "Innate," but for which there was no described mechanism. There is, of course, no evidence that "Innate" exists, and it's now rejected by many chiropractors.

The audible crack from chiropractic manipulation, Hall said, is just like knuckle cracking, and has no therapeutic effect except perhaps for its psychological impact. She noted that at least one chiropractor cracks her own wrists and doesn't actually touch her patients!

Osteopathy and Chiropractic
Hall compared osteopathy to chiropractic with this chart:

  • restoring blood flow
  • minimize spinal manipulation therapy (SMT)
  • adopted science
  • restoring nerve flow
  • maximize SMT
  • nope
Spinal manipulation therapy, said Hall, works as well as other treatments in treating back pain, and there is no evidence that it assists in treating anything other than back pain. A problem in testing SMT is that good placebo controls are impossible, because the patient can tell when SMT is occurring or not. Single blinding is impossible, let alone double blinding. There are also many variations of technique possible.

Tooth Fairy Science
Dr. Hall argued that chiropractic study is something like what she called "tooth fairy science." You could perform tests of the tooth fairy, by putting lost teeth into baggies vs. facial tissue before putting it under the pillow, comparing the amount of money received for the first lost tooth to the last lost tooth, looking for correlations with parental income, and so forth, but none of this would tell you anything about an entity called the Tooth Fairy.

She gave an anecdote of a man suffering from back pain who made an appointment with a chiropractor for the following Monday. Over the weekend, his pain went away--if he had made his appointment for Friday, he would have attributed the pain going away to the chiropractic treatment and perhaps ended up as a believer and regular patient.

She compared this to the "blue dot cure," a treatment by painting a blue dot on your nose (any nonsensical treatment suffices for the illustration). If the patient gets better, that's evidence that it worked. If the patient stays the same, that's evidence that the treatment kept him from getting worse. And if the patient gets worse, that's evidence that the disease was too far advanced, and if only he had come sooner it would have been treatable. (Or, alternatively, it's evidence that more treatment is required--say, upping the dosage of the remedy or painting a darker blue spot on the patient's nose.)

What chiropractors do well, Hall said, is help with back pain and act as good psychologists. But they've gotten thumbs down the New England Journal of Medicine, Consumer Reports, The Medical Newsletter, Canadian neurologists, and many other sources, not just because of claims to be able to treat things that it can't treat, but because of safety issues.

The Big Downside of Chiropractic
Chiropractic manipulation of the head and neck turns out to be dangerous. It can compress or tear vertebral arteries, resulting in strokes, perhaps as frequently as in one in a million manipulations, and perhaps 20% of basilar strokes are caused by spinal manipulations. Hall pointed out that mobilization is as effective as manipulation, yet is safe--so there's no reason to use the riskier method.

The Canadian neurologists mentioned above have recommended that signs warning signs be posted in chiropractic offices and that neck manipulation of children be prohibited.

Insurance data on payouts for chiropractic malpractice show that about 9% of payouts in 2002 were for "CVA," or cerebrovascular accident.

The numbers are likely under-reported, since there may be some time between a manipulation that causes damage and a stroke.

Chiropractors as Quack Magnets
A further problem with chiropractic is that practitioners are "quack magnets," promoting all sorts of bogus diagnostic methods and treatments such as moire contour analysis, use of a "neuroscope" that measures temperature differences and pressure, biofeedback as a form of electrodermal testing, applied kinesiology (pseudoscientific muscle strength testing), unnecessary dietary supplements, homeopathy, and reflexology. Hall also mentioned B.J. Palmer's (D.D. Palmer's son) "Atlas Adjustment" technique, or "hole in one" technique, which suggests that manipulation of the Atlas vertebra is sufficient to cause the rest of the spine to fall into alignment.

Chiropractors also tend to overuse X-rays, such as taking full-spine X-rays which expose the reproductive organs and inevitably produce overexposed or underexposed areas. Proper X-raying focuses on smaller areas to get the right exposure.

Chiropractors offer bad advice, frequently discourage immunizations and other medical treatments, and they frequently miss diagnoses of real illnesses. In one test of chiropractors, patients were sent in to describe classic heart attack symptoms, but none of the chiropractors in the test recognized it or its significance, and none suggested that the patient visit an emergency room.

Types of Chiropractor
There are three major chiropractic groups. The International Chiropractors Association (ICA), or "straights," who practice only chiropractic. The American Chiropractic Association (ACA), or "mixers," who mix chiropractic with other diagnostic and treatment techniques. And the National Association for Chiropractic Medicine (NACM), who are attempting to reform chiropractic by disassociating it from Palmer's pseudoscience and using only evidence-based scientific medicine.

Chiropractic Thinking and Hallmarks of Pseudoscience
Hall gave some examples of chiropractic thinking that is blatantly wrong or harmful:
  • If spine is straight, we can't die.
  • Germs don't cause disease, or we'd all be dead.
  • Muscle testing to find allergies. (In one case, a patient was tested for job-related stress with applied kinesiology, by pushing down on his arm while he thought of work.)
  • Spinal adjustments as the only treatment for meningitis, resulting in the child's death--and it was the chiropractor's own child.
  • A "no-touch" chiropractor (cracking own wrists, mentioned above).
And examples of how chiropractic exhibits the hallmarks of pseudoscience:
  • "If science disproved it, I'd still use it."
  • It doesn't give up ineffective treatments.
  • It's made no progress over the last century.
  • It doesn't matter whether it's true as long as it makes you feel better.
Dr. Hall concluded her talk by giving several three examples of concrete harm from chiropractic taken from Tim Farley's "What's the Harm" website, which lists 312 specific cases of chiropractic harm:

Kristi Bedenbaugh: Suffered a stroke and died.
Sandra Nette: Suffered multiple strokes and was left paralyzed with locked-in syndrome.
Laurie Jean Mathiason: Fell into a coma and died after receiving 186 neck manipulations in a six-month period.

Dr. Hall recommended the Quackwatch site and Chirobase.org as online resources on chiropractic, and the book Inside Chiropractic by chiropractor Samuel Homola and Quackwatch founder Stephen Barrett.

In the Q&A session, Dr. Hall was asked whether chiropractors are required to follow a standard of care and whether informed consent is required. She said that informed consent is not required, it is voluntary, and the informed consent forms that she's seen are very bad. She was also asked how many chiropractors meet the good and safe criteria, and she made a guess of under 10%.

(Part four of my conference summary, on evidence-based medicine and homeopathy, is here. Part five, on chronic Lyme disease, is here. Part six, on online health and social media, and the closing Q&A panel, is here.)


private said...

I agree. Most traditional chiropractic or "crack your back" style chiropractic does more harm than good and leaves a person more and more dependent on the "crack" to feel better. However, a very new technique called Blair does not crack or twist or tork and deals only with the top 4 vertebrae. I already commented on your first post on this so i won't ramble. http://www.blairchiropractic.com/

Zeno said...

An excellent summary of chiroquacktic - I wish I had been there!

If anyone wants to keep up with happenings in the UK with the Simon Singh affair and the multiple complaints about chiropractors, see my blog: Zeno's Blog. There are some pages of links to other blogs, including a legal view of things on Jack of Kent's Blog.

Lippard said...


Thanks for the blog references. I hold out hope that the BCA's lawsuit will prove to be a strategic misstep that causes them far more trouble than if they had done nothing. I think that may already be the case, with the "backlash" of all of the complaints about the bogus claims (yes, I can say that here in the U.S.) of chiropractic offices and websites being filed with their local Trading Standards offices.

It reminds me a little bit of when Scientology tried to tangle with the Internet about 13 years ago.

Derek said...

Chiropractors are quite conservative in their approach. They don’t practice the usage of drugs and surgery for a large extent. If you are diagnosed with something serious like a neck fracture the best option in that case would be to visit a mainstream orthopedic doctor who make use of techniques that are most effective in such cases.

Janine Zargar