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24 August 2011

The Token Skeptics Strike Again!

This article is cross-posted from the Winnipeg Skeptics blog.

The following email appeared in my inbox, yesterday.

Hi Gem,

University of Winnipeg's newspaper The Uniter is putting together a piece on the legitimacy of chiropractic. As critics of alternate medicine, we would love to speak to a member of the Winnipeg Skeptics on the topic.

The interview can be done over the phone or via email. Unfortunately, I will be leaving town Thursday morning so the interview would have to be done tomorrow evening at the very latest.

Please let me know if someone is available to talk.

Chris Hunter, The Uniter

I've discussed chiropractic before; several times, in fact. This is also not the first time that the Winnipeg Skeptics have been invited to comment on a story by the Uniter: Ashlyn and I were interviewed last year for a piece about Winnipeg's Creation Museum. (I was initially displeased with that piece, but upon further reflection I understand the constraints under which the author was working.)

I put Chris in contact with Richelle McCullough, a medical student who has extensive biomedical research experience. Chris also asked us both to answer a few questions, and we obliged him.

Elementi di anatomia, by Francesco Bertinatti and Mecco Leone.
Public domain image courtesy of Wikimedia Commons.

Do medical professionals (doctors) ever tell their patients to visit chiropractors?

Richelle: Referrals are up to the individual physician and I'm sure it happens. Certainly, most insurance companies require a physician's prescription in order to reimburse expenses, so I would guess that many referrals happen by patient request.

Gem: I'm sure that many do. When it comes to so-called "alternative" medicine, many physicians are what Dr. Steven Novella calls "shruggies": they are unaware of or disinterested in any alternative modality that does not directly affect their area of expertise. Many doctors also (erroneously) assume that while alternative medicine is mostly ineffective, it is also harmless.

From a medical standpoint, is there any reason to see a chiropractor?

Richelle: There are no good studies that definitively show any benefit to chiropractic above that which is already included in medical sciences, and it's usually worse.The only thing that chiropractic appears to help is lower back pain. A meta-analysis of all the high quality trials assessing chiropractic for lower back pain was published earlier this year in Spine, and it concluded that chiropractic seemed to be as good as physiotherapy for the treatment of lower back pain, but neither were particularly effective. The paper included studies published in the British Medical Journal and the New England Journal of Medicine – big journals with rigorous standards. Pain is subjective and particularly prone to things like regression to the mean and the placebo effect. Nobody really knows how to effectively treat back pain, and I suspect that even the benefits seen with physiotherapy and chiropractic would disappear given more rigorous controls for medical attention and patient belief that the treatment will help.

Of course, there are many sects of chiropractors, and those who base their treatments on scientific thinking are in the minority. Chiropractic work is founded on vitalistic concepts and the assumption that the alignment of the spine somehow alters the flow of unmeasurable "energy" from the brain to the periphery. This sort of thinking has lead to all sorts of ridiculous claims, from the ability to cure asthma to a treatment for depression. We now know what causes asthma, and it has nothing to do with your spinal alignment. If "subluxations" caused all these health problems, then why do people never suddenly develop allergies or psoriasis after a back injury? Chiropractic treatment for things that have nothing to do with your spine might have short term benefits due to the placebo effect, but ultimately do nothing to treat the underlying disease.

It is ironic that CAM practitioners so often accuse medicine of not treating the root of the problems, and yet advocate spinal manipulation for things like stomach ulcers, which have a demonstrable bacterial cause that can only be effectively treated by a regimen of antibiotics. It's also interesting to note that they claim to treat very subjective diseases with a natural history of an ebb and flow of symptoms. Some days, asthma may be worse than others, and a paper published in the New England Journal of Medicine earlier this month demonstrated that although any treatment which involved seeing a practitioner made the patients feel better, only drug administration actually improved their ability to breathe. Making the patient feel better is an important part of medicine, but needs to be combined with demonstrable, quantitative improvement of the underlying illness as well. Chiropractic might fulfill the first goal, but certainly not the second outside of the natural ebb and flow of the illness.

Gem: Perhaps, but I'm not convinced.

Chiropractic began as a vitalistic philosophy which posited that health is related to the flow of a spiritual energy called "innate intelligence". While this energy has never been demonstrated to exist, the founder of chiropractic claimed that interruptions or disturbances in its flow (called "vertebral subluxations") were the root of all disease. While some chiropractors (sometimes called "reforms") have moved beyond subluxation theory and take an evidence-based approach dealing primarily with back pain, many chiropractors still claim to treat a host of diseases for which there is no evidence that chiropractic is effective, and considerable evidence that it is not. (Examples include asthma, allergies, and even infections.)

It's safe to say that if your complaint is not musculoskeletal in nature, chiropractic is likely to be useless. Recent systematic reviews have shown that evidence for chiropractic efficacy for lower back pain is equivocal at best. Of course, all such conclusions are provisional and subject to revision should the state of the evidence change.

Are there serious risks associated with neck adjustments or other chiropractic treatments?

Richelle: There have been several high profile cases in which individuals have died or had strokes after neck manipulation, including a class action lawsuit out of Edmonton after a woman was paralyzed. The arteries which run along the vertebrae in the neck can be dramatically kinked, or even torn during something as simple as turning your head too rapidly, let alone during a sudden jerk from a chiropractor. Risks range from sudden death to stroke up to a few days later, when the clot becomes dislodged and travels to the brain. It's unlikely that this is a case of mere correlation, since a 2001 study by Rothwell and others found that people under 45 presenting to the hospital with stroke were five times more likely than controls to have seen a chiropractor within the week. It certainly seems to be a very real risk.

There's also the risk of misinformation. For example, many chiropractors actively promote anti-vaccine sentiments under the guise of informing their patients, instead encouraging them to use chiropractic to "boost their immune system." The lack of information being spread about vaccines in recent years has resulted in new outbreaks of measles, rubella, and other completely preventable diseases. There's currently a measles outbreak going on in Minnesota, and unvaccinated two toddlers are in critical condition. Side effects from vaccines are extraordinarily rare, and the consequences of an outbreak can be devastating, even lethal. There is no such thing as boosting the immune system - it's a completely meaningless phrase with no basis in physiology or biochemistry. Vaccines work by preparing the body to deal with a very specific kind of invader. No amount of non-specific "immune boosting" is going to protect you against any specific pathogen. Even if chiropractic work increased the general activity of the immune system, that is typically not a good thing, leading to things like allergies and auto-immune diseases, which can also apparently be treated with chiropractic work. So which is it – does chiropractic work increase or decrease the activity of the immune system?

Many chiropractors also take multiple x-rays of their patients over the course of treatment, sometimes several a year. Although physicians routinely use x-rays as well, they are used in a way which takes into account the diagnostic benefit with the risks of radiation. Some chiropractors take x-rays of all their patients on their first visit as a policy – whether such a thing is necessary or not! Subluxations cannot be reliably identified by x-ray between chiropractors, so it's an unreliable test and therefore exposes patients to unnecessary radiation. If you have ever been concerned about radiation doses from body scanners in airports, you should also be concerned about radiation from chiropractic x-rays.

Finally, there's the use of spinal manipulation on children. There's no excuse for doing this, as their bones are not fully formed, especially in infants, who are mostly flexible cartilage, which does not need manipulation. Since children do not have lower back pain, there is no demonstrable benefit for the use of spinal manipulation in children, which means any potential side effect pushes the risk-benefit scale well into "this is a really bad idea" territory.

Gem: Very serious complications have been associated with cervical spinal manipulation, but these are fairly rare.

Keep in mind, however, that it's not only the risk that we're concerned with: it's looking at the balance between risk and benefit. All medical interventions carry risks, and it's important to make an informed decision while understanding the probable outcome. I am not convinced that the benefits of chiropractic manipulation outweigh the risks.

Acupuncture, for example, has been demonstrated to be no more effective than poking the patient with toothpicks. However, this placebo is actually preferable to "real" acupuncture, because it does not carry the risk of infection.

Why are patients not made aware of risks associated with neck adjustments?

Richelle: One of my biggest issues with "alternative" medicine is the lack of informed consent provided to individuals. I believe strongly that people have the right to choose their treatment, but informed consent implies that you not only understand the benefits of your treatment course, but also the risks, how it works, and what other alternatives there are to consider. Do chiropractors ever explain that physiotherapy is equally effective in clinical trials as chiropractic for lower back pain, and holds fewer risks? Do they ever explain to their patients that they can only expect a mild decrease in the severity of their back pain, especially over the long term? Do they explain that there is not any agreement within chiropractic on what a spinal subluxation is, since there is no way to measure it? And do they ever tell them, when offering spinal manipulation for the treatment of non-muscle-skeletal issues, that it has never been demonstrated to be effective in a randomized, controlled clinical trial? The good ones, perhaps, but this is certainly not in the majority.

Chiropractors are there to sell their services. Your family doctor gets paid whether you go home with or without a prescription - if you leave a chiropractor's office without an adjustment, they've lost out on money for that visit, and all the potential subsequent visits. As the standards of chiropractors are self-determined, it says a lot that few chiropractors are willing to stand up for the rights of the patient.

Gem: That's a question that is probably best addressed to a chiropractor.

Are there alternative options to chiropractors? Other types of professionals that deal with the problems a chiropractor might deal with?

Richelle: If someone is dealing with lower back pain, physiotherapy is a good option. They can do spinal manipulation when medical necessary, but more importantly, can help you strengthen the supporting muscles to prevent future re-injury. There's not a lot of improvement that someone can expect with any treatment for lower back pain, but at least a physiotherapist can provide guidance to help it from getting worse.

As for the myriad of other problems that some chiropractics claim to be able to treat, people should talk to their family doctor. Chiropractors are not qualified to deal with behavioural disorders, respiratory illness, rheumatological problems, cardiovascular disease, infections, or other medical problems. People should be sure that they learn what their science-based treatment options are and fully understand them before they decide not to use them.

Gem: When examined through the lens of science-based medicine, chiropractic offers little to distinguish itself from physiotherapy. For short to medium term relief of muscular pain, therapeutic massage also has a good track record.

When dealing with a medical complaint, a visit to a real, honest to goodness medical doctor is always a good first step. He or she may then refer you to an appropriate specialist.

In general, what are some changes that need to take place within the chiropractic community for it to become a safer, better form of alternate medicine?

Richelle: Chiropractors need to become their own worst critics. It is only through the process of rigorous peer-review that chiropractors can purge the pseudo-science from their midst. This will require throwing out the vitalistic concepts of "innate intelligence" and subluxations, and examining the premises of chiropractic in the context of modern science. They need to be open to being wrong, and willing to follow where the research leads them. They need to strictly enforce the use of informed consent, and hand out punishment to those who take advantage of patients. If chiropractors used good science as the basis for their treatments, they would quickly find themselves not in the realm of "alternative medicine," but of simply, medicine. Sadly, that day has not yet come.

Gem: First of all, it's important to note that "alternative medicine" is not really a useful classification. It's a catch-all term for any medical modality that suffers from a dearth of evidence. As comedian/musician Tim Minchin said, "You know what they call alternative medicine that's been proved to work? Medicine."

Obviously, I'm no expert, but the first thing that I'd like to see from chiropractic is a standard of care. Chiropractic needs to embrace a science-based approach to treatment that takes into account both evidence and plausibility.

Most importantly of all, the reform needs to start from within. This can't be us versus them: chiropractors who embrace science-based medicine need to be vocal in their criticism of the pseudoscience practised by their peers.

Anything else you would like to add?

Richelle: There is nothing "alternative" about chiropractic, because that adjective implies that is equally valid as the science-based practices in medicine. When something has been definitively demonstrated to be effective as compared to an appropriate placebo and the current standard of care, it becomes part of medicine. There is no alternative medicine: just medicine that works, and medicine that does not or has not been proven yet. The parts of chiropractic that fall into the latter category are not being excluded from medicine because there is some overarching dogma. They're being excluded because they promote pre-scientific thinking, they encourage dangerous behaviours like refusal of vaccines, and they don't work better than a placebo for the majority of treatments.

Gem: When evaluating any claim, it's important to be aware of your own biases. Recognise that you are not an impartial observer, and that your personal experience does not constitute scientific evidence. We can all easily be fooled by confirmation bias, regression to the mean, and other effects that increase the chances we will perceive a benefit where none exists. Fortunately, science can equip us to better assess the state of the evidence as impartially as we can.

If you have some time, I also highly recommend reading Sam Homola's article The Image of Chiropractic: Consensus Based on Belief on Science-Based Medicine. Dr. Homola is a "retired chiropractor turned skeptic", and provided a good overview of the subject, along with recommendations on finding a good, science-based chiropractor.

Addendum (6 September 2011): The Uniter article has gone live: "The great chiropractic debate".


  1. There are many people who believe that Chiropractic medicine really works. If you are going to relate this to ancient medicine which is still available at present times, Chiropractic practice can be compared to acupressure. I've known several people who underwent this kind of alternative treatment, and they've given positive feedback. The most important thing for an individual to do, is to look for the best and legitimate Chiropractor to prevent further injury.


    1. Chiropractic is not ancient: it less than 150 years old. The fact that many people believe in it doesn't make it a worthwhile endeavour; this is the fallacious argument from popularity. The fact that your friends had positive experiences is not useful evidence of efficacy; these are anecdotes, and quite vague anecdotes at that.