OBJECTIVES: To validate Rheumatoid Arthritis Outcomes Analyzer, a data analysis tool with a user-friendly interface incorporating pharmacy, medical claims, and member eligibility information, by using data from two distinct commercially insured patient populations.  METHODS: The framework for the Rheumatoid Arthritis Outcomes Analyzer was developed based on published treatment guidelines and evidence-based literature.  The analyzer facilitates importation of claims and eligibility files and to perform outcomes analyses.  Analysis of patients ≥ 18 years of age who received at least one traditional (non-biologic) or biologic DMARD medication between January 2005 and December 2007 was conducted using HealthCore’s Integrated Research Database (Cohort #1) and a comparator commercial dataset (Cohort #2).  All patients had at least two RA diagnoses (ICD-9 CM 714.0X) more than two months apart. RESULTS: A total of 25856 vs. 14383 RA patients, 19331 (74.8%) vs. 10869 female (75.6%), were identified in Cohorts #1 vs. #2 with a mean age of 56 and 55 years respectively.  The mean Charlson Comorbidity Index was 2.00 (SD=1.63) vs. 2.06 (SD=1.68).  Prescription-level analyses revealed a total of 492195 vs. 263294 prescriptions for DMARDs with 348074 (70.7%) vs. 183639 (69.7%) traditional, 132448 (26.9%) vs. 77291 (29.4%) anti-TNF biologics and 11673 (2.4%) vs. 2364 (0.9%) non anti-TNF biologics.  Concomitant corticosteroid use was identified in 15636 (60.7%) vs. 8728 (60.7%) of patients in Cohorts #1 vs. #2 while NSAIDS and narcotic analgesics were used by 14538 (56.4%) vs. 8717 (60.6%) and 15024 (58.3%) vs. 8113 (56.4%) respectively.  Behavioral health medications were the next most prevalent concomitant medication used in 11571 (44.95) vs. 6197 (43.1%) of patients. CONCLUSIONS: Analytic tools like the Rheumatoid Arthritis Outcomes Analyzer will allow payers and policy makers to better understand utilization and treatment patterns easily and quickly.  Replication and validation of outputs from these tools are important to establish the precision of results.