The purpose of this study is to assess the effectiveness of Abatacept in real-world clinical practice. The main hypothesis to be examined in this study is, "Abatacept's effectiveness results in a single real-world clinic (n = 100) are reproducible at another site (n ~= 200)".

Two secondary hypotheses that will be tested are:

• Abatacept aids in achieving low disease activity or clinical remission in patients of the following Rheumatoid Arthritis (RA) sub-groups: RF+/CCP+, RF+/CCP- RF-/CCP+ RF-/CCP-; first time on a bio-tech drug; having previously failed a biological drug; having interstitial lung disease; identified as disabled; twenty-eight individual joints identified as {swollen, painful, tender, deformed or having decreased range of motion}; on or not on oral DMARD; age; or gender.
• A database with sufficient attributes exists from which a patient's efficacy on abatacept is accurately predictable.

Inclusion Criteria:

• Diagnosed with rheumatoid arthritis
• Have used Abatacept for 3 or more months

Exclusion Criteria:

• None

All rheumatoid arthritis patients from a single site who have been on Abatacept for greater than 3 months.