An epidemiological examination of the subluxation construct using Hill's criteria of causation.

BACKGROUND: Chiropractors claim to locate, analyze and diagnose a putative spinal lesion known as subluxation and apply the mode of spinal manipulation (adjustment) for the correction of this lesion. AIM: The purpose of this examination is to review the current evidence on the epidemiology of the subluxation construct and to evaluate the subluxation by applying epidemiologic criteria for it's significance as a causal factor. METHODS: The databases of PubMed, Cinahl, and Mantis were searched for studies using the keywords subluxation, epidemiology, manipulation, dose-response, temporality, odds ratio, relative risk, biological plausibility, coherence, and analogy. RESULTS: The criteria for causation in epidemiology are strength (strength of association), consistency, specificity, temporality (temporal sequence), dose response, experimental evidence, biological plausibility, coherence, and analogy. Applied to the subluxation all of these criteria remain for the most part unfulfilled. CONCLUSION: There is a significant lack of evidence to fulfill the basic criteria of causation. This lack of crucial supportive epidemiologic evidence prohibits the accurate promulgation of the chiropractic subluxation.

Does chiropractic 'add years to life'?

The chiropractic cliché "Chiropractic Adds Life to Years and Years to Life" was examined for validity. It was assumed that chiropractors themselves would be the best informed about the health benefits of chiropractic care. Chiropractors would therefore be most likely to receive some level of chiropractic care, and do so on a long-term basis. If chiropractic care significantly improves general health then chiropractors themselves should demonstrate longer life spans than the general population. Two separate data sources were used to examine chiropractic mortality rates. One source used obituary notices from past issues of Dynamic Chiropractic from 1990 to mid-2003. The second source used biographies from Who Was Who in Chiropractic - A Necrology covering a ten year period from 1969-1979. The two sources yielded a mean age at death for chiropractors of 73.4 and 74.2 years respectively. The mean ages at death of chiropractors is below the national average of 76.9 years and is below their medical doctor counterparts of 81.5.This review of mortality date found no evidence to support the claim that chiropractic care "Adds Years to Life."