Abstract
Objective To evaluate the cost-effectiveness over 5 years of treat-to-target treatment strategies in early DMARD-naïve RA initiating tocilizumab (TCZ) +/- methotrexate (MTX) versus initiating MTX.
Methods Data on resource use were collected with questionnaires at baseline, 3, 6, 12, 24 months and yearly thereafter, and were converted to costs using Dutch reference prices. QALYs were calculated using EQ5D-5L, with utility based on Dutch tariff or estimated by HAQ. To account for missing cost- and QALY data and for sample uncertainty, first bootstraps (10,000 samples) were obtained. Secondly, single imputation using chained equations nested within these bootstrap samples was performed. An economic evaluation was performed for TCZ+MTX and TCZ, compared to MTX as initial treatment in a treat-to-target strategy from a healthcare and a societal perspective over 5 years. Several sensitivity analyses were performed.
Results Mean differences in QALYs were small and not significant (TCZ+MTX vs. MTX: 0.06 (95%CI -0.10 to 0.22); TCZ vs. MTX: -0.03 (95%CI -0.20 to 0.13)). Limited savings in indirect non-healthcare costs and productivity loss costs (for TCZ only) were observed but these did not compensate for the higher medication costs. Sensitivity analyses did not materially change these findings, although lower-priced TCZ, or reserving TCZ as initial therapy for prognostically unfavorable RA patients improved cost effectiveness considerably, but did not individually lead to a strategy being cost-effective.
Conclusion Based on our analyses, early initiation of TCZ(+MTX), is not cost-effective compared to MTX initiation in a step-up treat-to-target treatment strategy over 5 years in early RA patients.
