Since its publication, “the Cassidy paper” has been the defensive citation used by chiropractors to respond to accusations that neck adjustments involve a risk of stroke, and therefore should not be conducted without proven benefit and informed consent. The abstract seems to strongly exonerate chiropractors: “We found no evidence of excess risk of VBA stroke associated with chiropractic care compared to primary care.”
“But abstracts are like movie trailers,” as Dr. Mark Crislip wrote. “They give a flavor of the movie, but often leave out many important plot devices and characters. … If you were to read this article in its entirety, you would not be so sanguine about the safety of chiropractic.” He goes on to explain exactly why in one of the earliest popular posts on ScienceBasedMedicine.org, Chiropractic and Stroke: Evaluation of One Paper.
“Risk of vertebrobasilar stroke and chiropractic care: results of a population-based case-control and case-crossover study”