Maxime Verhoeven

12 Chapter 1 healthcare professional. The OST-score (i.e., the score of the HandScan measurement) has been found to correlate with the grade of inflammation of hand joints as assessed by ultrasonography, coefficient ρ=0.54. 19 Although the effectiveness of treatment for RA has been markedly improved in the last two decades, total costs of the disease have increased. A Scandinavian registry study has shown that total cost of RA between 1990 and 2010 increased with 32%. 20 The main cost driver of this increment is drug costs, which increased from 3% to 33% of total costs. 20 Given the availability and greater use of bDMARDs, which are considerably more expensive than csDMARDs, this is not surprising. On the other hand, due to better treatment, indirect costs (i.e., costs associated with productivity loss) decreased with 17%, from 75% to 58% of total costs. In addition, inpatient care decreased with 12%, to only 3% of total costs. 20 These results indicate that RA patients are more productive and less often hospitalized for their disease nowadays. 21 Increase in medication costs underlines that benefits of modern treatment strategies, including drawbacks as expensive medication and regularly monitoring disease activity as well, should be weighed against the total costs of RA. Therefore, additional improvements in care for RA patients should contribute to control, not only of disease activity, but also of the cost effectiveness of treatment strategies. For example, tapering of medication when the treatment target is achieved, has been found to be a feasible option and has now been incorporated in European League Against Rheumatism (EULAR) recommendations for management of RA. 22,23 Improvements in care for RA patients might also be expected from exploring and evaluating effectiveness of treatment strategies using combinations of (relative cheap) csDMARDs compared to treatment strategies using the more costly bDMARDs, including protocolized tapering of DMARD treatment. If treatment response in individual patients would be predictable, further benefits might be expected from prediction of treatment response to enable a more stratified ‘personalized’ treatment strategy. If (combinations of) csDMARDs could be used instead of bDMARDs in specified subpopulations of RA without loss of effectivity, this would improve cost effectiveness of treatment, at least on the short term. Vice versa, the cost effectiveness of bDMARDs might improve when they are introduced early in the disease with a strict tapering strategy, and only patients really needing this treatment will remain on this treatment. Besides facilitating every application of tight-control DMARD treatment strategies, (cost-)effectiveness of care for RA might be further improved if a novel disease measuring device, which is operated without the need for a healthcare professional, would result in less patient visits to the rheumatologist, only of patients with active disease, saving rheumatologists’ time. 10,24 Based on this background, the first part of this thesis is aimed t o evaluate the effectiveness and cost-effectiveness of DMARD therapy approaches in treat-to-target