A cost-cost study comparing etanercept with infliximab in rheumatoid arthritis

The objective of this study was to compare the total costs associated with the administration of two different tumour necrosis factor (TNF) strategies used in the treatment of rheumatoid arthritis (RA): etanercept, a soluble TNF receptor that can be administered at home by subcutaneous injection, versus infliximab, an antibody that requires an intravenous infusion in a hospital outpatient setting. The main analytical framework of the study was a cost-cost analysis comparing the total annual costs associated with the administration of etanercept and infliximab in adult RA patients. The perspective of the study was that of the Dutch society. An economic model was constructed to determine the costs of both treatments. The cost evaluation included direct medical costs, direct nonmedical costs and indirect costs. The base-case analysis compared monotherapy with etanercept versus a combination therapy with infliximab and methotrexate. Data for the economic model came from published literature, expert opinion and official price and tariff lists. All costs were in 1999 values. The analysis was performed for the adult RA population eligible for treatment with etanercept or infliximab in The Netherlands. The analysis showed that the total annual drug costs per patient do not differ substantially between infliximab and etanercept, with costs of Netherland guilders (NLG)31,526 (12,610 US dollars) and NLG31,334 (12,534 US dollars), respectively. However, the other medical costs (i.e. excluding the costs of the two drugs themselves) are substantially higher for infliximab due to the additional costs associated with administration in an outpatient clinic and the use of methotrexate [NLG 12,621 (5048 US dollars) versus NLG269 (107 US dollars) for etanercept]. The impact of direct nonmedical costs (transportation) and indirect costs were negligible. Overall treatment with infliximab is more expensive than treatment with etanercept with total costs of NLG45 115 (18,046 US dollars) and NLG3I,621 (12,648 US dollars), respectively (42.7% increase). Based on the assumptions used in the model, we may conclude that the use of etanercept compares favourably with infliximab from a budgetary and health economic perspective: the total costs are substantially lower when the efficacy of etanercept is assumed to be at least equivalent to the efficacy of infliximab.