<qa>  What type of treatment may be included in the study?Patients 18 years of age or older who were diagnosed with rheumatoid arthritis after age 16 and who have active arthritis 6 or more tender joints may be eligible for this study. Of particular interest are patients beginning treatment with prednisone, methotrexate, leflunomide, infliximab, or etanercept, although patients receiving any type of treatment may be included. 