OBJECTIVES: To examine the resource utilization and direct costs of care associated with comorbid cardiovascular disease (CVD) and depression among prevalent rheumatoid arthritis (RA) patients using retrospective healthcare claims data. METHODS: Patients ³ 18 years of age with a diagnosis of RA January 1, 2002-December 31, 2004 were selected. The date of the first observed claim with an RA diagnosis following a one year period of health plan enrollment was the “index date.” Patients had 12-month pre-index and follow-up periods. Patients were also required to have a diagnosis of RA and RA-related treatment during pre-index. Based upon pre-index utilization, patients were classified into mutually exclusive diagnosis groups: RA with comorbid depression; RA with comorbid CVD; RA with comorbid CVD and depression; RA alone. Annual utilization and costs were calculated; generalized linear models (GLM) were undertaken, controlling for demographic and clinical characteristics. Analyses focused on differences in costs among RA only vs. comorbid diagnosis groups. RESULTS: A total of 8916 patients had RA alone (86.6%), 608 had RA+CVD (5.9%), 716 had RA+depression (7.0%), and 58 had RA+CVD+depression (0.5%). Mean age varied by cohort group with RA+CVD tending to be older (RA+CVD: 59 years; RA+depression: 50 years; RA+CVD+depression: 53 years; RA alone: 51 years). A significantly lower proportion of patients with RA alone had a RA-related hospitalization stay during follow-up (5.4%) compared with other groups (RA+CVD: 9.4%; RA+depression: 9.2%; RA+CVD+depression: 15.5%, all p?0.001). In GLM modeling, adjusted mean annual costs were highest for RA+CVD ($14,328) followed by RA+CVD+depression ($13,276), RA+depression ($12,270), and RA alone ($11,522). CONCLUSION: A significant portion of prevalent RA patients has comorbid CVD and/or depression (13.4%). Comorbid depression and cardiovascular events are associated with significant increase in not only the annual total medical costs, but there may also be associated increases in RA-related utilization.