Utilization Trends of Tumor Necrosis Factor Inhibitors Among Patients with Rheumatoid Arthritis in a United States Observational Cohort Study

Objective. Studies have suggested that early institution of tumor necrosis factor (TNF) inhibitors improves functional status and slows radiographic progression among patients with rheumatoid arthritis (RA). To determine whether these findings have altered practice patterns, we used the Consortium of Rheumatolooy Researchers of North America (CORRONA) registry to assess the pattern of TNF inhibitor utilization in the US over time. Methods. Demographics and disease activity data were collected for patients with RA. The trend of TNF inhibitor use during 2002-06 was evaluated prospectively using linear and logistic regression models. Results. Of the 1 1 397 patients with RA, 66% and 34% had established RA and early RA (disease duration < 3 yrs), respectively. The majority of patients were female and Caucasian. Despite comparable levels of disease activity, more of the patients with established RA were taking TNF inhibitors than those with early RA (40% vs 25%; p < 0.0001). The majority of patients (70%) taking TNF inhibitors were also receiving disease modifying antirheumatic drugs. The use of TNF inhibitors increased at a rate of 2.8% per year in established RA and 1.2% per year in early RA. The mean Clinical Disease Activity Index at the start of TNF inhibitors decreased at a rate of -0.233 per quarter (p = 0.006), while the mean Disease Activity Score decreased at a rate of -0.04 per quarter (p = 0.022). Conclusion. Utilization of TNF inhibitors in this multicenter, observational US cohort is increasing in both early and established RA, although it is more prominent among patients with established RA. The level of disease activity at which TNF inhibitors were initiated decreased over time in patients with both established and early RA. (First Release April 15 2009; J Rheumatol 2009;36:1611-7; doi:10.3899/jrheum.080889)