OBJECTIVES: To evaluate switching patterns among anti-tumor necrosis factor therapies (anti-TNFs) in rheumatoid arthritis (RA) patients. METHODS: A retrospective patient chart review study was conducted in six rheumatology clinics across the US. The first anti-TNF encounter among RA patients between 2002 and 2004 was identified. Patients were required to have a minimum of 12 months of continuous records prior to and following their index biologic date. Three mutually exclusive cohorts were developed based on biologic therapy: infliximab, etanercept or adalimumab. Switching was defined as discontinuation of the index anti-TNF and initiation of another anti-TNF agent. The rates of switching and time before switching were examined. RESULTS: Of 496 patients analyzed, 266 (53.6%) received infliximab, 146 (29.4%) received etanercept, and 84 (14.1%) received adalimumab. 74% of patients were female, with an average age of 56.1 years. Overall, 87 (17.5%) patients switched anti-TNF therapy during the follow-up period. Patients in the infliximab group had a lower switch rate (31 patients, 11.7%) compared with patients in the etanercept (38 patients, 26%) and adalimumab (18 patients, 21.4%) groups. Chi-Square analyses indicated the differences among three groups were statistically significant (p<0.001). The infliximab group had a longer average time before switching (342 days), compared with those in the etanercept (266 days) and adalimumab (341 days) groups;(p =ns). Lack of effectiveness and safety concerns were the most common reasons for switching (28.6%). CONCLUSION: The switching rate and time before switching are important measures of the effectiveness of RA treatment in real world practice. This chart review study found that infliximab is associated with a lower switching rate and longer time before switching, as compared with etanercept and adalimumab, both of which had higher switching rates and shorter time to switching. Further studies to evaluate the association of switching with clinical, economic, and humanistic outcomes are recommended.