Maxime Verhoeven

14 Chapter 1 and (external) validation of a new disease activity index using the HandScan. The value of this new index, versus that of DAS28, to classify RA as active versus inactive, using the rheumatologist’s clinical classification as reference, was investigated in chapter 11. The OST-score, obtained by the HandScan, might be influenced by gender as shown in this chapter. Therefore, in chapter 12, RA patients as well as controls are studied to explore whether OST-scores differ between males and females, and to determine which factors influence OST-scores, and which are accountable for the gender difference. The results of all chapters are summarized and discussed in the final chapter, chapter 13 and placed in a broader perspective, with suggestions for future research and care. REFERENCES 1. Smolen, J. S., Aletaha, D. & McInnes, I. B. Rheumatoid arthritis. Lancet 388 , 2023–2038 (2016). 2. Smolen, J. S. et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update. Ann. Rheum. Dis. 79 , 685–699 (2020). 3. Sloot, R. et al. Reumatische aandoeningen in Nederland: Ervaringen en kengetallen . (2016). 4. Allaire, S., Wolfe, F., Niu, J., Lavalley, M. & Michaud, K. Work disability and its economic effect on 55-64-year-old adults with rheumatoid arthritis. Arthritis Care Res. 53 , 603–608 (2005). 5. Rijksinstituut voor Volksgezondheid en Milieu. Reumatoïde artritis (RA) → Preventie & Zorg → Zorg. Volksgezondheidenzorg.info https://www.volksgezondheidenzorg.info/onderwerp/ reumatoïde-artritis-ra/preventie-zorg/zorg (2020). 6. Raza, K. & Filer, A. The therapeutic window of opportunity in rheumatoid arthritis: does it ever close ? Ann. Rheum. Dis. 74 , 793–794 (2015). 7. van Nies, J. A. B., Tsonaka, R., Fautrel, B. & van Mil-van der Helm, A. H. M. Evaluating relationships between symptom duration and persistence of rheumatoid arthritis: does a window of opportunity exist? Results on the Leiden early arthritis clinic and ESPOIR cohorts. Ann. Rheum. Dis. 74 , 806–812 (2015). 8. Cush, J. J. Early rheumatoid arthritis - Is there a window of opportunity? J. Rheumatol. 80 , 1–7 (2007). 9. Singh, J. a et al. 2015 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Rheumatol. 68 , 1–26 (2016). 10. Ramiro, S. et al. Is treat-to-target really working in rheumatoid arthritis? A longitudinal analysis of a cohort of patients treated in daily practice (RA BIODAM). Ann. Rheum. Dis. 79 , 453–459 (2020). 11. Teitsma, X. M. et al. Inadequate response to treat-to-target methotrexate therapy in patients with new-onset rheumatoid arthritis: development and validation of clinical predictors. Ann. Rheum. Dis. 77 , 1261–1267 (2018). 12. Emery, P., Sebba, A. & Huizinga, T. W. J. Biologic and oral disease-modifying antirheumatic drug monotherapy in rheumatoid arthritis. Ann. Rheum. Dis. 72 , 1897–1904 (2013). 13. Felson, D. T. et al. American College of Rheumatology/European League Against Rheumatism provisional definition of remission in rheumatoid arthritis for clinical trials. Arthritis Rheum. 63 , 573–586 (2011). 14. Porter, D. et al. DAS28 and rheumatoid arthritis: the need for standardization. Musculoskeletal Care 9 , 222–227 (2011).