Data Notes:

  1. The figures reflect admissions to acute care hospitals and those undergoing diagnostic and/or surgical procedures in outpatient and free-standing ambulatory care facilities. The following are not included: those with symptoms not severe enough to warrant hospitalization; those treated in the physician’s office; those treated in the emergency department and then released. These counts reflect admissions, not persons. For example, if an individual was admitted on two separate occasions during this time period, they were counted twice.
  2. The figures reflect admissions where arthritis is the principal diagnosis (the diagnosis code which after review is deemed the reason for admission). Exceptions include ICD.9.CM codes 711.0x-711.9x and 713.0-713.8 (part of the definition for "arthritis from infection/disorder") where cases were counted if the code was the principal diagnosis or the first secondary diagnosis.
  3. The figures reflect the principal procedure coded for arthritis. If multiple procedures were performed only the principal procedure was counted.
  4. Arthritis type including arthritis from infection, osteoarthritis, and other unspecified arthritis may include some cases of spinal arthritis where the site was coded as other, unspecified or multiple.
  5. The data were reported as submitted to us by the hospital. If a hospital failed to provide complete information, the number of hospitalizations would be undercounted.
  6. The figures reflect same day admission and discharge as a one day length of stay. Furthermore, all outpatient admissions are counted as a one day length of stay.
  7. Median charges are reported. It is important to note that these charges are associated with the entire hospitalization (not just treatment associated with arthritis), and they are hospital charges only (they do not include physician fees, etc.). Further, while charges are a standard way of reporting data, they do not reflect the actual cost of the treatment nor do they reflect the payment that the hospital may have actually received.
  8. Definitions of arthritis type and arthritis-related treatments and the ICD.9.CM codes (International Classification of Diseases, Ninth Revision, Clinical Modification) used in this analysis were as follows:

Arthritis Type:

Note: The x includes digits of 0-9 to identify the site of disease.

Treatment Type:


Spine-Related Arthritis:

Rheumatoid Arthritis: