Cost-Effectiveness of TNF-Blocker Injection Spacing for Patients with Established Rheumatoid Arthritis in Remission: An Economic Evaluation from the Spacing of TNF-Blocker Injections in Rheumatoid Arthritis Trial

摘要

Background: In patients with rheumatoid arthritis in remission, a disease activity-driven tapering of adalimumab or etanercept relying on progressive injection spacing has not been shown to be equivalent to a maintenance strategy at full dose in terms of disease activity in the Spacing of TNF-blocker injections in Rheumatoid ArthritiS Study (STRASS) trial. Objectives: To evaluate the costeffectiveness of such a spacing strategy based on the data of the STRASS trial. Methods: This is a cost-utility analysis of the STRASS trial, a French multicenter 18-month equivalence randomized open label controlled trial that included patients at stable dose for at least 1 year, in remission for at least 6 months. Effectiveness was assessed in quality-adjusted life-years (QALYs). Costs involved in the study period were assessed from a payer perspective. The decremental cost-effectiveness ratio (DCER) was calculated in the complete cases sample (n = 98). Several sensitivity analyses were conducted and the impact of missing data on DCER estimate was investigated. An acceptability analysis was performed. Results: In the spacing arm, TNF-blockers were stopped for 34.1% of the patients, tapered for 43.2%, and maintained at full dose for 18.2%. The spacing strategy was associated with less QALYs gain (mean difference of-0.158; 95% confidence interval [CI]-0.085 to-0.232) and reduced costs (mean difference of- 8,440; 95% CI-6,507 to-10,212). The estimated DCER of the spacing strategy over the maintenance at full dose was 53,417 saved per QALY lost (95% CI 32,230 to 104,700). Conclusions: The spacing strategy appears cost-effective, but the acceptability of such a QALY loss reported to the cost avoided remains to be evaluated, because no consensual threshold has been determined for willingness to accept as compared with willingness to pay. Copyright (C) 2017, International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc.