Approximately 21 million Americans - 9.5 percent of adults 18 and older - either visited or called a doctor for a prescription to reduce arthritis pain in 2005, according to the latest News and Numbers from the Agency for Healthcare Research and Quality.

The most common form of arthritis is osteoarthritis. It is usually associated with aging and most often causes pain and stiffness in the fingers, knees, and hips. A less common form of arthritis is rheumatoid arthritis, occurring when the body's own defense system doesn't work properly, causing pain in the joints and bones. Rheumatoid arthritis may also affect internal organs and systems.

AHRQ's data found that in 2005:

Some 9.5 million adults sought treatment, but women did it more often than men - 12 percent vs.7 percent.

More whites sought treatment for arthritis (10.5 percent), followed closely by blacks (just under 10 percent), compared to Hispanics (6 percent), and Asians (4 percent).

About $32 billion was spent for arthritis treatments, which included doctor visits (36 percent), hospital care (31 percent), prescription drugs (21 percent), home health care (12 percent) and emergency room visits (less than 1 percent).

AHRQ, which is part of the U.S. Department of Health and Human Services, works to enhance the quality, safety, efficiency, and effectiveness of health care in the United States. The data in this AHRQ News and Numbers summary are taken from the Medical Expenditure Panel Survey, a detailed source of information on the health services used by Americans, the frequency with which they are used, the cost of those services, and how they are paid. For more information, go toArthritis: Use and Expenditures among U.S. Noninstitutionalized Population, 2005.

AHRQ