Racial/ethnic differences in the use of biologic disease-modifying antirheumatic drugs among California Medicaid rheumatoid arthritis patients.

OBJECTIVE: To assess racial/ethnic differences in the use of biologic disease-modifying antirheumatic drugs (DMARDs) among California Medicaid (Medi-Cal) rheumatoid arthritis (RA) patients. METHODS: Medi-Cal patient level data for 5,385 DMARD recipients between ages 18 and 100 years with at least 1 diagnosis of RA (International Classification of Disease, Ninth Revision, Clinical Modification code 714.xx) and the use of 1 DMARD between January 1, 1998 and December 31, 2005 were collected. The outcome of interest was the choice of either standard DMARDs (methotrexate, lefluonomide, hydroxychloroquine, and sulfasalazine) or biologic DMARDs (adalimumab, etanercept, anakinra, and infliximab). A univariate analysis and logistic regression model were applied to examine the association of the choice of DMARD among different racial/ethnic groups. RESULTS: In the univariate analysis, biologic DMARD use was significantly associated with race/ethnicity (P < 0.001). In the multivariate logistic regression model, after adjusting for age, sex, insurance coverage, 12 comorbid conditions, RA-related drug prescription, RA-related inpatient stay, and rehabilitation visits, African Americans had 53% lower odds of receiving biologic DMARDs as compared to whites, whereas Hispanics had 36% increased odds of receiving biologic DMARDs as compared to whites. CONCLUSION: In this Medi-Cal population, with its racial diversity and relatively homogenous socioeconomic status and health care benefits, racial/ethnic differences were found in RA patients receiving biologic DMARDs.