Longitudinal analysis of the use of etanercept versus infliximab determined from medical chart audit.

OBJECTIVE To describe the dosing of etanercept and infliximab for the treatment of rheumatoid arthritis (RA). METHODS Adult patients with a diagnosis of RA who were treated with either etanercept or infliximab between 1999 and 2002 were selected from 16 rheumatology practices in the western and southeastern United States. Patients with a terminal illness or those receiving a tumor necrosis factor (TNF)-alpha inhibitor for an indication other than RA were excluded. Data were collected through a review of the patient medical records. Data collected on each patient included demographics, concurrent disease-modifying antirheumatic drug therapy, TNF-alpha inhibitor dose, frequency, duration of TNF-alpha inhibitor therapy, and discontinuation of TNF-alpha inhibitor therapy. RESULTS A total of 244 patients were included in the evaluation (etanercept only [n=128; 52%], infliximab only [n=89; 36%], both [n=27; 11%]). The mean age of these patients was 55.1+/-13.3 years, 54.9+/-13.5 years, and 52.8+/-14.0 years, respectively; the mean duration of RA was 13.3 +/- 8.8 years, 13.4+/-8.0 years, and 14.0 +/- 9.9 years, respectively. Female patients constituted 70% of the sample. Health maintenance organization insurance was the most common form of medical insurance (45.8%), followed by Medicare (22.3%). The mean duration of follow-up for etanercept and infliximab treatment was 29.3+/-14.1 months and 14.8+/-6.9 months, respectively. Among patients who were still receiving therapy at the time of review, the mean initial and last etanercept doses were 25.0 mg versus 25.8 mg (P=0.16); the mean initial and last infliximab doses were 3.38 mg/kg versus 4.51 mg/kg (P<0.001). CONCLUSION The dosing of etanercept and infliximab therapy was consistent with the approved labeling of both medications.