Maxime Verhoeven

161 Editorial; unravelling the cost of biological strategies in RA the (medication) cost perspective, but also the clinical perspective, could be relevant. What were the clinical effects of treating the extra patients with a bDMARD? Could the potential savings of using the biosimilar not have been more (cost-)effective spent on another treatment strategy? Take for instance a strategy with initiation of a bDMARD, preferably a biosimilar, next to MTX, in early RA, using the bDMARD for a limited period (thus limiting medication cost), targeting for drug free remission. This seems an attainable goal, given the results of the U-Act-Early trial. 1 In this study, approximately 30% of the early RA patients who started with a bDMARD (tocilizumab) as first treatment shortly after diagnosis achieved this target, whereas this was only 10% in the strategy group initiating MTX as first treatment. 1 The cost effectiveness analysis of the 2-year U-Act-Early trial and its 3-year post-trial follow-up period, during which treatment was according to the decision of the rheumatologist, 2 showed that the strategies initiating tocilizumab as first therapy in early RA were over these 5 years not cost-effective, compared to a strategy initiating MTX and later on adding tocilizumab, if indicated. A possible explanation, next to the finding that bDMARD use in the strategy arms during the study period became more similar as consequence of the strict treat-to-target strategy, is the lack of tapering during the non-protocolled follow-up period. 3 Again, this underlines that for strategies aiming to save costs or improve cost effectiveness, clear recommendations on the use and strategy of expensive DMARD are needed, which have to be adhered to. In the study described above, selecting a prognostically unfavourable subgroup based on DAS28 and HAQ notably improved cost effectiveness. This suggests that it remains essential for rheumatology communities to continue developing novel strategies with bDMARD in RA, to reduce cost and improve long-term effectiveness. How we are looking: methodology of costing studies Müskens et al. performed a quasi-experimental (before after) study and data was collected in daily practice, appropriate to study real-world effects. However, only medication cost for RA was analysed, only in one hospital, a rather limited scope. A justification is that in the Netherlands, also for outpatients, bDMARD are paid for and delivered by the hospital. Discounts on the maximal governmentally set bDMARD purchase prices are negotiated by each individual hospital (or collaborative hospital group) with the pharmaceutical companies. Which percentage of the bDMARD cost is reimbursed to the hospital (groups) by the health insurance organisations is negotiated between these two parties, see Figure. 4 This (intricate) system explains the interest of individual Dutch hospitals in number and cost of bDMARD prescribed in their center. As such, the results of the paper of Müskens are important. However, the negotiated prices of biologicals are not made available publically, and these, and not reference prices were used in the analyses of Müskens. 5 This hampers generalizability of the results of this study in a single center. Interestingly, after introduction of biosimilars on the Dutch 8