In 1979, the government of New Zealand published an objective study of chiropractic. The purpose of its inquiry was to determine the merits of including chiropractic in its Social Security and Accident Compensation programs. Many issues were studied, including cost effectiveness, chiropractic education and training, safety issues, and patient satisfaction.
Among other things, the resulting 377 page document concluded that chiropractic would have a positive influence on the health of a country. One of the chapters was devoted towards the safety of chiropractic spinal adjustments.
The commission investigated two safety issues that had been commonly raised by chiropractic critics. The first being the safety of chiropractic spinal adjustments, and the second, the notion that seeking chiropractic care delays medical treatment. After extensive inquiry the researchers found both safety concerns to be unfounded. Because of the lack of evidence of the contrary, the commissioners determined chiropractic care to be remarkably safe.
Chiropractic in New Zealand Report of the Commission of Inquiry, 1979, Page 78.