Effect on costs and quality-adjusted life-years of treat-to-target treatment strategies initiating methotrexate, or tocilizumab, or their combination in early rheumatoid arthritis

Abstract

Objective. Our study aimed to evaluate the cost effectiveness of initiating tocilizumab (TCZ) ± methotrexate (MTX) versus initiating MTX as treat-to-target treatment strategies over 5 years in early disease-modifying antirheumatic drug (DMARD)-naïve rheumatoid arthritis (RA). Methods. Data on resource use were collected with questionnaires at baseline, 3, 6, 12, and 24 months, and yearly thereafter, and were converted to costs using Dutch reference prices. Quality-adjusted life-years (QALY) were calculated using the EQ5D5L, with utility based on Dutch tariff or estimated by the Health Assessment Questionnaire. To account for missing cost data and QALY data and for sample uncertainty, first bootstraps (10,000 samples) were obtained. Second, 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 societal perspective over 5 years. Several sensitivity analyses were performed. Results. Mean differences in QALY were small and not significant (TCZ + MTX vs MTX: 0.06, 95% CI –0.02 to 0.13; TCZ vs. MTX: –0.03, 95% CI –0.05 to 0.11). Limited savings in indirect nonhealthcare 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.