A573was inadequate response from traditional disease-modifying anti-rheumatic drugs (DMARDs) alone (54.9%), followed by symptom control (13.4%). Among the remaining responses, clinical data (e.g., results from clinical trials) was cited most frequently in the UK (17.1%) compared to Germany/Spain (9.0%/4.7%), while personal experience was cited most in Germany (15.3%) vs. UK/Spain (2.7%/0.9%). Inadequate response to DMARDs was most frequently reported for adalimumab (61.5%) vs. etanercept (46.9%) or other biologics (40.2%); inadequate DMARD symptom control was more cited for etanercept (18.8%) vs. adalimumab (11.1%) or other biologics (9.8%). Among the 23 patients who switched to a second biologic agent, 72.7% were switched due to inadequate response to the first biologic agent. ConClusions: Across the three study countries, prescribers most frequently initiated biologic therapy due to inadequate response or lack of symptom control on traditional DMARDs. Other reasons varied by country, however differences across biologic agents prescribed were minimal.