Dose adjustment over time of etanercept and infliximab in patients with rheumatoid arthritis.

: Dose escalation of biologics in patients with rheumatoid arthritis may affect the cost of care. Longitudinal claims data from a large U.S. health plan were analyzed retrospectively. A total of 4,426 health plan members had a medication claim for either etanercept (N = 690; mean age, 48.4 yr; 72% female) or infliximab (N = 424; mean age, 54.3 yr; 73% female) during the selection period. The study revealed that the mean dosage in patients receiving infliximab for rheumatoid arthritis symptoms increased by 29% from first to last dose. The mean weekly dosage for etanercept remained stable. Etanercept was associated with a significantly lower hazard of dose increase relative to infliximab. The estimated annual costs of infliximab and its administration varied by 31%, whereas the estimated costs of etanercept remained stable over time. This increased dose of infliximab may translate into increased costs for a payer over time.