"So far, we know for sure that mild to moderate as well as serious complications, including deaths, do occur after chiropractic spinal manipulations, particularly those of the upper spine. What we cannot say with absolute certainty is whether they are caused by the treatment or whether they happened coincidentally. Our knowledge in this area relies mostly on case-reports and surveys which, by their very nature, do not allow causal inferences. Therefore chiropractors have, in the past, been able to argue that a causal link remains unproven. A brand-new blinded parallel group RCT might fill this gap in our knowledge and might reject or establish the notion of causality once and for all...what does this new study tell us? In my view, it is strong evidence to suggest a causal kink between chiropractic treatment and mild to moderate adverse effects." Edzard Ernst's blog (27th June 2013)