OBJECTIVES: Biologic Disease-Modifying Antirheumatic Drugs (bDMARDs) reduce joint damage and pain among rheumatoid arthritis (RA) patients. This study assesses RA disease activity (DA) measures [Routine Assessment of Patient Index Data 3 (RAPID3), Clinical Disease Activity Index (CDAI), Swollen Joint Counts (SJC), Tender Joint Counts (TJC)] among patients classified as new starts of anti-tumor necrosis factor alpha (TNFα) bDMARD.

METHODS: This study used the OM1 RA Registry (OM1, Boston, MA), a continually enrolling, representative sample of RA patients in the US followed prospectively by rheumatologists, which incorporates clinical EMR and linked administrative claims data. The analysis included patients starting TNFα bDMARD (2015-2018) with at least one DA measure from six months prior to index date (bDMARD start date). Patients with TNFα bDMARD in the six months prior, or multiple bDMARDs on index date were excluded. Baseline characteristics and RA scores stratified by bDMARD on index date were reported. Analyses were performed using the Instant Health Data platform (BHE, Boston, MA).

RESULTS: Of the 156,541 patients in the OM1 RA Registry, 10,706 met cohort criteria (median age 58 years; 78.9% female; 68.1% white; 60% commercial insurance; 46.2% obese). Patients initiated adalimumab (33.5%), etanercept (26.9%), infliximab (15.9%), golimumab (12.7%) or certolizumab pegol (11%). Mean SJC-28 ranged from 4.0-4.7. Mean TJC-28 ranged from 5.5-6.6. Proportion of patients with severe baseline DA by CDAI was highest among patients initiating certolizumab pegol (38.4%), followed by infliximab (36.4%), golimumab (36.2%), etanercept (32.2%), and adalimumab (26.3%). Although the pattern was consistent, rates of severe DA by RAPID3 scores were substantially higher across all treatment groups compared to by CDAI (range 51.8%-59.0%).

CONCLUSIONS: As seen in a real-world database, although DA measures are correlated with each other, patient-reported measures (RAPID3) provide additional insights to disease severity as the effects of physical limitations and pain on daily living are appreciated.