Chiro.Org Blog:

Although it is well recognized that national costs associated with back and neck conditions have grown considerably in recent years, little is known about the costs of care for specific ambulatory health services that are used to manage this population. Between 1999 and 2008, the mean inflation-adjusted annual expenditures on medical care for these patients increased by 95% (from $487 to $950); most of the increase was accounted for by increased costs for medical specialists, as opposed to primary care physicians.