OP0283 COMPARING COST-UTILITY OF DMARDS IN SERONEGATIVE RHEUMATOID ARTHRITIS PATIENTS; A TREACH SUBANALYSIS

Background: The diversity of the clinical phenotype of rheumatoid arthritis (RA) is increasing due to the emphasis on early diagnosis and treatment. This resulted in an increased number of RA patients without autoantibodies, also known as seronegative RA. We recently showed that newly diagnosed seronegative RA patients initially treated with hydroxychloroquine (iHCQ) had a similar clinical efficacy to initial methotrexate (iMTX). To our knowledge, however, there are no data on the cost-effectiveness of different initial treatment strategies in seronegative RA patients. Objectives: To evaluate the 1-year cost-effectiveness between three different initial treatment strategies in seronegative rheumatoid arthritis (RA) patients, according to 2010 criteria. Methods: For this analysis we selected all seronegative RA patients (n=131) within the intermediate probability stratum of the tREACH trial (table 1). Selected patients either received initial methotrexate 25mg/week (iMTX), hydroxychloroquine 400mg/day (iHCQ) or oral glucocorticoids, starting dose 15mg, in a 10-week tapering scheme without csDMARDs (iGCs). Quality adjusted life year (QALY) were derived from the EQ-5D. Costs were calculated with data from patient records and questionnaires. Direct costs are health care costs, whereas indirect costs are costs due to productivity loss. The incremental cost-effectiveness ratio (ICER) was used to assess the cost-effectiveness between treatment strategies. Results: Average QALYs (sd), for iMTX, iHCQ and iGCs were respectively 0.71 (0.14), 0.73 (0.13) and 0.70 (0.15). The average total costs (sd) per QALY for iMTX, iHCQ and iGCs were respectively €11.004 (17.611), €13.231 (19.886) and €18.415 (35.660). Direct and indirect costs were higher in the iGCs group compared to iMTX and iHCQ (table 2). The ICERs did not differ between the initial treatment strategies (figure 1A-C). For WTP levels €33.900 iHCQ has the highest probability (figure 1D). Conclusion: iMTX and iHCQ are more cost-effective than iGCs. However, depending on the WTP threshold either iMTX or iHCQ has the highest probability of being cost-effective. Disclosure of Interests: None declared