The objective was to estimate the cost-effectiveness of TNF-inhibitors for the treatment of rheumatoid arthritis in Swedish clinical practice, both as a first and second biological treatment, with or without the combination of conventional DMARDs. Further sub-group analysis of etanercept treatment was performed.
Patient level data were obtained from three regions of the Swedish Rheumatology Registers. The dataset contained 2,558 patients who had started TNF-inhibitor treatment, 1,049 with etanercept as their first biological treatment. A total of 819 patients had switched to a second TNF-inhibitor, of which 425 to etanercept. A Markov cohort model was used in which health states of disease severity were classified according to HAQ and DAS28. Disease progression and discontinuation rates of TNF-inhibitors were based on the registry and for the comparator on published literature. Mortality, costs and utilities were based on Swedish data. The main analysis had a societal perspective over 20 years and efficacy was measured in quality-adjusted life-years (QALYs).
TNF-inhibitor treatment was associated with an increase in QALYs and an incremental cost compared to no biological treatment. The cost per QALY gained with the three TNF-inhibitors ranged from euro 50,000 to euro 120,000, with lower estimates for TNF-inhibitors used in combination with MTX and as a first biologic. At a progression of 0.045 for the comparator, most values remain within the accepted range for cost-effectiveness.
These results demonstrate that the cost per QALY for TNF-inhibitors was higher than in previous assessments based on registry data and that the results were sensitive to the HAQ progression of the comparator.