Sorry to hear about the identity theft; but it's obviously unfair to project that upon all DCs.
The increased stroke association in those <45 was higher for those visiting a DC, but it was also higher for those visiting a PCP (the PCP group had increased association for those patients >45 as well.
http://www.ncbi.nlm.nih.gov/pubmed/18204390
This was the first time a study looked at chiro's association AND medical association with stroke, and found it was there for both practice types. The proposed theory is that the vertebral artery dissection may begin, causing neck pain for which the patient presents to either their DC or MD. That's not to say that sudden vertebrobasilar artery dissection can't occur suddenly due to HVLA. But the authors state "we found no evidence of excess risk of VBA stroke associated with chiropractic care compared to primary care."
from above: 818 CVA in 100M patient/years. Case control study, studies association, not causation. The conclusion from the abstract is completely unsupported by the paper. Read the article or listen to the critique of the conclusion. At timepoint 20:30 on the mp3 podcast.
http://moremark.squarespace.com/quackcast-list-mp3/
If not convincing, at least entertaining. Dr. Crislip addresses your questions and concerns and pokes fun at you at the same time. It was a chiro authored article with full spin.
Neurologist. 2008 Jan;14(1):66-73.
Does cervical manipulative therapy cause vertebral artery dissection and stroke?
Miley ML, Wellik KE, Wingerchuk DM, Demaerschalk BM.
Division of Neurosciences, Faculty of Science, Loyola University, Chicago, IL, USA.
OBJECTIVE: Does cervical manipulative therapy (CMT) cause vertebral arterial dissection (VAD) and subsequent ischemic stroke? What is the best estimate of the incidence of CMT associated with VAD and ischemic stroke? METHODS: The questions were addressed with a structured evidence-based clinical neurologic practice review. Participants included neuroscience students, consultant neurologists, clinical epidemiologists, medical librarians, and clinical content experts. A critically appraised topic format was employed, starting with a clinical scenario and structured question. The participant group devised search strategies, located and compiled the best evidence, performed critical appraisals, synthesized the results, summarized the evidence, provided commentary, and declared bottom-line conclusions. RESULTS: The search yielded 169 citations, of which 55 were deemed most relevant. From this return, we selected 26 publications of the highest evidence available: 3 case-control studies, 8 prospective and retrospective case series studies, 4 illustrative case reports, 1 survey, 1 systematic review of observational research, 5 reviews, and 4 opinion and expert commentary pieces. Five of the applicable 7 criteria for causation were satisfactorily met and supported weak to moderate strength of evidence for causation between CMT and VAD and associated stroke, especially in young adults. Young vertebrobasilar artery territory stroke patients were 5 times more likely than controls to have had CMT within 1 week of the event date (OR 5.03, 95% CI, 1.32-43.87). No significant associations were found for those > or =45 years of age. The best available estimate of incidence is approximately 1.3 cases of VAD or occlusion attributable to CMT for every 100,000 persons <45 years of age receiving CMT within 1 week of manipulative therapy. CONCLUSIONS: Weak to moderately strong evidence exists to support causation between CMT and VAD and associated stroke. Ultimately, the acceptable level of risk associated with a therapeutic intervention like CMT must be balanced against evidence of therapeutic efficacy. Further research, employing prospective cohort study designs, is indicated to uncover both the benefits and the harms associated with CMT.
Spine J. 2002 Sep-Oct;2(5):334-42.
Clinical perceptions of the risk of vertebral artery dissection after cervical manipulation: the effect of referral bias.
Haldeman S, Carey P, Townsend M, Papadopoulos C.
Department of Neurology, University of California, 101 City Drive, Orange, CA 92868, USA.
[email protected]
BACKGROUND CONTEXT: The growing recognition of cervical manipulation as a treatment of neck pain and cervicogenic headaches has lead to increased interest in potential complications that may result from this treatment approach. Recent surveys have reported that many neurologists will encounter cases of vertebral artery dissection that occur at various times after cervical manipulation, whereas most practitioners of spinal manipulation are of the opinion that these events are extremely rare. We asked the question whether these differences in perception could be explained in part by referral or selection bias. PURPOSE: To assess the effect of referral bias on the differences in perceived incidence of vertebral artery dissection after cervical manipulation between neurologists and chiropractors in Canada. STUDY DESIGN: This study was a retrospective review of cases where neurological symptoms consistent with cerebrovascular ischemia were reported by chiropractors in Canada. METHODS: An analysis of data from a chiropractic malpractice insurance carrier (Canadian Chiropractic Protective Association [CCPA]) and results of a survey of chiropractors was performed to determine the likelihood that a vertebral artery dissection after cervical manipulation would be reported to practicing chiropractors. This was compared with the likelihood that a neurologist would be made aware of such a complication. RESULTS: For the 10-year period 1988 to 1997, there were 23 cases of vertebral artery dissection after cervical manipulation reported to the CCPA that represents 85% of practicing chiropractors in Canada. Based on the survey, an estimated 134,466,765 cervical manipulations were performed during this 10-year period. This gave a calculated rate of vertebral artery dissection after manipulation of 1:5,846,381 cervical manipulations. Based on the number of practicing chiropractors and neurologists during the period of this study, 1 of every 48 chiropractors and one of every two neurologists would have been made aware of a vascular complication from cervical manipulation that was reported to the CCPA during their practice lifetime. CONCLUSIONS: The perceived risk after cervical manipulation by chiropractors and neurologists is related to the probability that a practitioner will be made aware of such an incident. The difference in the number of chiropractors (approximately 3,840 in 1997) and neurologists (approximately 4,000 in 1997) in active practice and the fact that each patient who has a stroke after manipulation will likely be seen by only one chiropractor but by three or more neurologists partly explains the difference in experience and the perception of risk of these two professions. This selection or referral bias is important in shaping the clinical opinions of the various disciplines and distorts discussion on the true incidence of these complications of cervical manipulation. The nature of this study, however, describes the likelihood that a clinician will be made aware of such an event and cannot be interpreted as describing the actual risk of stroke after manipulation.
Y'all go listen to quackcast 27 from twenty minutes onward. Come back and report your thoughts. It's only 5-10 minutes- and well worth it.
http://moremark.squarespace.com/quackcast-list-mp3/