OBJECTIVES: To examine if: (1) time to initiation (TTI) of biologic DMARD therapy (B-DMARD) differs by non-biologic DMARD (NB-DMARD) type and therapy; and (2) likelihood of initiation of B-DMARD differs by NB-DMARD type and therapy while controlling for covariates. METHODS: Texas Medicaid medical and prescription claims from 7/1/03-12/31/10 were extracted for adults (18-63 years) who were diagnosed with rheumatoid arthritis (ICD-9 CM 714.0x) with no use of DMARDs in the preindex period. The index date was the first date of NB-DMARD use. The likelihood of initiating B-DMARDs was compared among on NB-DMARD type [methotrexate(MTX), sulfasalazine(SSZ), hydroxychloroquine(HCQ), leflunomide(LEF)] and NB-DMARD therapy (mono vs. dual), while controlling for demographic factors (age, gender, race), NB-DMARD adherence [proportion of days covered (PDC)≥70% vs. <70%], persistence, pain medication, glucocorticoid use, and Charlson Comorbidity Index score (CCI). Descriptive statistics, Kaplan-Meier, Log-rank test, and logistic regression were utilized. RESULTS: The subjects (n=2,714) were 48.1±10.4 years old, primarily female (89.1%), and Hispanic (55.3%). The majority were on pain medications (92.4%), glucocorticoid users (64.9%), and NB-DMARD monotherapy users (86.4%); while, 24.3% initiated on B-DMARDs and 46.7% had a CCI score=1. Compared to TTI (days) of B-DMARDs for MTX (208.3±190.1) users, TTI of B-DMARDs was longer for SSZ (284.5±186.4) and HCQ (256±184.4) users and shorter for LEF users (188.0±205.1);p<0.0001). There were no differences between mono and dual therapy users. After controlling for covariates, regression results showed that compared to MTX, SSZ users were 66.8% less likely (OR=0.322;95%CI=0.237-0.464;p<0.0001) and HCQ users were 79.0% less likely (OR=0.210;95%CI=0.160-0.278;p<0.0001) to initiate B-DMARD therapy. NB-DMARD monotherapy users were 47.5% more likely (OR=1.475;95%CI=1.121-1.940;p<0.0001) to initiate B-DMARD therapy compared to dual therapy users. CONCLUSIONS: Time to B-DMARD initiation ranged from 6.3 (LEF) to 9.5 months (SSZ). Patients who used NB-DMARD MTX and those on monotherapy may be more likely to initiate on B-DMARD therapy.