On January 19, 2008, the following article was published in the Globe and Mail:
Alphonso, C. Chiropractors don’t raise stroke risk, study says. Globe and Mail; January 19, 2009. The article begins:
A Canadian study indicates there is no increased risk related to chiropractic treatment in the heated debate about whether neck adjustments can trigger a rare type of stroke.
Researchers say patients are no more likely to suffer a stroke following a visit to a chiropractor than they would after stepping into their family doctor’s office.
The findings, published today in the journal Spine, help shed light on earlier studies that had cast a cloud on the chiropractic profession and suggested that their actions resulted in some patients suffering a stroke after treatment.
This article was referring to one of the studies published in the special Spine supplement entitled Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders:
Cassidy JD, Boyle E, Cote P, He Y, Hogg-Johnson S, Silver F, Bondy SJ. Risk of vertebrobasilar stroke and chiropractic care: Results of a population-based case-control and case-crossover study. Spine 2008; 33 (4S):S176-S183.
The study concludes: VBA stroke is a very rare event in the population. The increased risks of VBA stroke associated with chiropractic and PCP visits is likely due to patients with headache and neck pain from VBA dissection seeking care before their stroke. We found no evidence of excess risk of VBA stroke associated chiropractic care compared to primary care.
Here is a related study, published in the same issue:
Boyle E, Cote P, Grier AR, Cassidy JD. Examining vertebrobasilar artery stroke in two Canadian provinces. Spine 2008; 33 (4S):S170-S175.
The study concludes: In Saskatchewan, we observed a dramatic increase in the incidence rate in 2000 and there was a corresponding relatively small increase in chiropractic utilization. In Ontario, there was a small increase in the incidence rate; however, chiropractic utilization decreased. At the ecological level, the increase in VBA stroke does not seem to be associated with an increase in the rate of chiropractic utilization.