Effects of a Managed Chiropractic Benefit on the Use of Specific Diagnostic and Therapeutic Procedures in the Treatment of Low Back and Neck Pain

Here is yet another study, with clear evidence of the cost-effectiveness of chiropractic services. 

Basically, the study confirms that for the treatment of low back and neck pain, the inclusion of a chiropractic benefit resulted in a reduction in the rates of surgery, advanced imaging, inpatient care, and plain-film radiographs. This effect was greater on a per-episode basis than on a per-patient basis.  Dr. Press

http://www.jmptonline.org/article/S0161-4754%2805%2900240-X/abstract