ABSTRACT

Chronic pain has become the Western world’s most expensive, disabling, and common disorder. An estimated 45 million Americans suffer from some form of chronic headache, which costs the U.S. economy $50 billion directly and indirectly (National Headache Foundation, 2003). Arthritis afflicts nearly 50 million Americans and accounts for 36 million outpatient visits and 750,000 hospitalizations annually (Centers for Disease Control, 2004).