Objective: To evaluate long-term switching patterns among anti-TNFs in patients with rheumatoid arthritis (RA). Methods: A retrospective study utilizing the PharMetrics managed-care claims database was conducted. RA patients' first anti-TNF encounter between January 1, 2000 and December 1, 2006 was identified. Patients were required to have ³30 months of continuous plan eligibility; 6 months prior to and 24 months following their index date, as patients were followed-up for 24 months after the index biologic date. Rates of switching and days before switching were compared among three cohorts based on their index biologic agent (infliximab, etanercept and adalimumab) plus methotrexate (MTX). Univariate and multivariate statistical analyses were conducted to determine if differences existed among the three cohorts. Results: Of 2155 patients analyzed, 605 (28.1%) received infliximab therapy, 1121 (52.0%) received etanercept therapy, and 429 (19.9%) received adalimumab therapy; 75% were female and the mean age was 49.5 years. Age, gender, Charlson Comorbidity Index and disease staging were similar among the three cohorts. During the 24 months follow-up, 376 patients (17.4%) switched to another anti-TNF: 88 patients (14.5%) in the infliximab cohort switched compared to 203 (18.1%) in etanercept group and 85 (19.8%) in the adalimumab group (p=0.0728). The mean time to switch for all patients was 342.1 days. The infliximab group had an average time of 395.4 days, compared to 329.7 days in the etanercept group, and 321.0 days in the adalimumab group (P=0.0173). After controlling for demographic variables and disease severity, differences among the three cohorts were statistically significant (p<0.05). Conclusion: Switching among therapies is an important measure of the effectiveness of RA treatment. This study found that, in a two-year follow-up period, infliximab plus MTX is associated with a lower switching rate and longer time before switching, as compared to the other anti-TNFs.