At last, the definitive nail in the coffin of chiropractic? Hardly. A recent study in the journal Chiropractic and Osteopathy uses an epidemiological approach to examine the question of whether the founding “lesion” of the chiropractic philosophy, the vertebral subluxation, can be shown to be associated with any disease. Their conclusion reads like a Science-Based Medicine or Quackwatch summary:
“Subluxation was not found to be linked to any one disease complex…There were no studies that offered a biological plausibility that would isolate subluxation as a causal factor in disease. There were no studies linking the subluxation as a coherent construct and supported by generally known facts about the natural history and biology of any disease. There were no studies found that suggested the subluxation as a causal agent similar to other factually demonstrated causal agents…There is significant lack of evidence to fulfill basic criteria of causation. This lack of crucial supportive epidemiologic evidence prohibits the accurate promulgation of the chiropractic subluxation.”
Short and sweet, the basic abnormality chiropractors claim to fix cannot be shown to exist or to cause any disease. One might think this would be a fatal blow to the enterprise of chiropractic, but sadly that is not the case. For one thing, it has been shown before in other studies that the subluxation cannot be reliably identified by chiropractors and that when pushed to demonstrate it in some objective way, most chiropractors and their lobbying organizations engage in some impressive yoga to cover the fact that they cannot. But as chiropractic is fundamentally faith-based medicine, being unable to demonstrate that the disease they are treating exists doesn’t worry chiropractors. Even those who disavow the subluxation theory happily continue the sort of manipulative practices Palmer originally invented to fix the supposed subluxation, and they simply justify it with the time-honored refuge of all woo, “Well, I don’t know how or why it works, but it works!”
Of course, this conclusion cannot be reliably demonstrated by objective evidence either. Though chiropractic does seem to have some benefit on subjective perceptions idiopathic lower back pain, the fact is it has been shown to be at best roughly equivalent to conventional therapy (rest, NSAIDs, physical therapy, and patient education materials) or to a good massage. If it were truly risk free and presented truthfully as offering mild benefits for back pain, I would have no objections. And a few chiropractors have adopted this approach in an attempt to take what benefit their interventions might provide out of the realm of faith and into that of responsible medicine, but these are a minority and often reviled within their own profession. But while I believe evidence is critical and should be the cornerstone of medical practice, I also understand that it is not as compelling as personal experience for many people, and the first step on the road to recovery from addiction to unscientific therapies is to understand we have a problem and need something better than our own experience and intuition to validate or invalidate the safety and efficacy of medicine. So while this should be a critical study undermining the claims of mainstream chiropractic, it has garnered little attention and will probably have little impact on the popularity of the method.