Abstract
BACKGROUND: Societal decision makers increasingly emphasise their need for evidence based economic analyses to make reimbursement decisions. OBJECTIVE: To analyse the cost utility of adalimumab, on both incremental cost and incremental quality adjusted life years (QALYs), versus traditional disease modifying antirheumatic drugs and the other tumour necrosis factor (TNF) antagonists suitable for submission to the Swedish LFN (Pharmaceutical Benefit Board). METHODS: Swedish unit costs and treatment guidelines from a lifetime perspective were implemented. A mathematical model, incorporating data from seven trials, simulated the experiences of 10 000 hypothetical patients with moderate to severe rheumatoid arthritis (RA). The primary outcome measure-QALYs-was derived from utility values calculated from a relationship between the Health Assessment Questionnaire (HAQ) Disability Index (DI) and Health Utility Index-III (HUI-3) from adalimumab trial results. The model followed the progression of HAQ-DI through a number of treatments in a sequence accounting for mortality, drug and monitoring costs, and other direct costs. RESULTS: When using ACR50 as a response threshold for determining successful treatment, adalimumab plus methotrexate showed the greatest number of QALYs gained (2.3 from one study and 2.1 from the pooled results of two trials). The etanercept plus methotrexate strategy yielded QALY gains similar to the pooled adalimumab results. Except for the infliximab strategy, the costs results were between 35 000 and 42 000, a range normally considered cost effective in other European countries. CONCLUSION: Adalimumab appears to be cost effective for the treatment of moderate to severe RA. The results suggest that adalimumab is at least as cost effective as other TNF antagonists.