Study To Evaluate The Response To Enbrel And The Impact Of Rheumatoid Factor(RF) And Anti-Cyclic Citrullinated Peptide(Anti-CCP) In Rheumatoid Arthritis(RA) Patients

Primary outcomes

1. Disease Activity Score 28 (DAS28) in Participants With Positive Rheumatoid Factor (RF) and Anti-Cyclic Citrullinated Peptide (ACCP) at Last Follow-up Visit (Month 12)

   Time frame: Month 12 visit during retrospective data collection period of approximately 7 years

   DAS28 calculated from the number of swollen joints (SJC) and painful joints (PJC) using the 28 joints count, the erythrocyte sedimentation rate (ESR) (in millimeters per hour [mm/hour]) and patient's global assessment (PGA) of disease activity (participant rated arthritis activity assessment with transformed scores ranging 0 to 10; higher scores indicated high disease activity). DAS28 less than equal to (<=) 3.2 = low disease activity, DAS28 greater than (>) 3.2 to 5.1 = moderate to high disease activity. DAS28 score in participants with positive RF and ACCP were reported in this outcome measure.

2. Clinical Disease Activity Index (CDAI) Score in Participants With Positive Rheumatoid Factor (RF) and Anti-Cyclic Citrullinated Peptide (ACCP) at Last Follow-up Visit (Month 12)

   Time frame: Month 12 visit during retrospective data collection period of approximately 7 years

   The CDAI is the numerical sum of 4 outcome parameters: tender joint count (TJC) and SJC based on a 28-joint assessment, PGA and physician global assessment (PhGA) assessed on 0 to 10 centimeter (cm) visual analog scale (VAS); higher scores = high disease activity. CDAI total score = 0 to 76. CDAI <= 2.8 indicates disease remission, > 2.8 to 10 = low disease activity, > 10 to 22 = moderate disease activity and > 22 = high disease activity. CDAI score in participants with positive RF and ACCP were reported in this outcome measure.

3. Disease Activity Score 28 (DAS28) in Participants With Negative Rheumatoid Factor (RF) and Anti-Cyclic Citrullinated Peptide (ACCP) at Last Follow-up Visit (Month 12)

   Time frame: Month 12 visit during retrospective data collection period of approximately 7 years

   DAS28 calculated from the SJC and PJC using the 28 joints count, the ESR (in mm/hour) and PGA of disease activity (participant rated arthritis activity assessment with transformed scores ranging 0 to 10; higher scores indicated high disease activity). DAS28 <= 3.2 = low disease activity, DAS28 > 3.2 to 5.1 = moderate to high disease activity. DAS28 score in participants with negative RF and ACCP were reported in this outcome measure.

4. Clinical Disease Activity Index (CDAI) Score in Participants With Negative Rheumatoid Factor (RF) and Anti-Cyclic Citrullinated Peptide (ACCP) at Last Follow-up Visit (Month 12)

   Time frame: Month 12 visit during retrospective data collection period of approximately 7 years

   The CDAI is the numerical sum of 4 outcome parameters: TJC and SJC based on a 28-joint assessment, PGA and PhGA assessed on 0 to 10 cm VAS; higher scores = high disease activity. CDAI total score = 0 to 76. CDAI <= 2.8 indicates disease remission, > 2.8 to 10 = low disease activity, > 10 to 22 = moderate disease activity and > 22 = high disease activity. CDAI score in participants with negative RF and ACCP were reported in this outcome measure.