OBJECTIVES: To estimate national and regional dose escalation patterns over two years of therapy among biologic naïve RA patients initiating etanercept, adalimumab, or infliximab using US managed care data.  METHODS: Adult (ages 18-65) RA patients who did not use RA biologics in the prior six months, initiating etanercept, adalimumab, or infliximab between July 1, 2005 and April 30, 2009 were identified using the MarketScan® Commercial Database. National and regional dose escalation rates were evaluated 12 and 24 months after initiation using the Single Instance Method (one claim with an average weekly dose at least 115%, 130%, or 150% greater than the initial weekly dose) and the Two Instances Method (two consecutive claims with an average weekly dose 130% greater than the initial weekly dose).  Dose escalation rates were compared using Fisher’s Exact tests.  RESULTS: A total of 2,747 patients met the inclusion criteria (mean age 50 years (SD=10), 74% female).  More patients resided in the South (45%) than North Central (28%), West (17%) or East (10%) US regions.  More patients (44%) initiated etanercept than adalimumab (37%) or infliximab (20%).  In the first year of therapy, dose escalation ranged from 0.8%-1.5% for etanercept, 10.8%-12.5% for adalimumab, and 16.4%-42.5% for infliximab using the single instance method; ranges at 24 months were 0.8%-2.1% for etanercept, 14.3%-17.5% for adalimumab, and 26.4%-57.6% for infliximab. At 12 and 24 and months respectively, the two instances method showed lower dose escalation rates for etanercept (0.8%, 0.8%) than adalimumab (8.7%, 13.3%) or infliximab (22.9%, 37.6%) at the 130% threshold (p<0.001). Dose escalation rates were consistent across US geographic regions, with etanercept having less dose escalation than adalimumab or infliximab across all regions.  CONCLUSIONS: RA patients initiating etanercept had lower dose escalation rates than patients initiating adalimumab or infliximab in the first and second year following therapy initiation and across US geographic regions.