SAT0312 GENDER CONTRASTS IN PATIENT REPORTED OUTCOMES DON’T ALTER THE DISEASE ACTIVITY SCORE IN AXIAL SPONDYLOARTHRITIS PATIENTS
Authors: Ann-Sophie De Craemer, Thomas Renson, Liselotte Deroo, Manouk de Hooge, Philippe Carron, Filip van den Bosch, Dirk Elewaut
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Disease activity in axial spondyloarthritis (axSpA) is often quantified by the Axial Spondyloarthritis Disease Activity Score (ASDAS), a composite index which combines 4 patient reported outcome (PRO) parameters and C-reactive protein (CRP) as an acute phase reactant. ASDAS commonly acts as a target in treat-to-target approaches in axSpA patients. <h3>Objectives</h3> To identify the impact of gender on ASDAS in newly diagnosed axSpA patients and to determine whether possible differences are PRO- or CRP-driven. <h3>Methods</h3> Patients originate from the Be-Giant cohort, a Belgian observational registry of newly diagnosed axSpA patients (expert opinion). Included patients fulfill the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axSpA and are anti-TNF naïve prior to inclusion. An extensive patient description was performed at baseline, including PRO and laboratory investigations with CRP (mg/L). ASDAS was calculated for each patient and subdivided in a PRO-component (ASDAS-PRO) and a CRP-component (ASDAS-CRP) (1). <h3>Results</h3> By January 2019, 291 axSpA patients were included (138 male, 153 female). At baseline, ASDAS could be calculated in 262 patients. ASDAS-PRO was significantly higher in women compared to men (1,66 vs. 1,48, p = 0,04), while ASDAS-CRP did not differ significantly (0,90 for both genders, p = 0,96). No significant difference was found between the total ASDAS of women and men (2,54 vs. 2,38, p = 0,09) (Figure 1). When categorizing the score into 4 disease activity states (2), 60,8% (76/125) of men show high or very high disease activity (ASDAS &gt; 2.1) at baseline compared to 67,2% (92/137) of women (p = 0,35). Concerning the 5 ASDAS components, the discrimination between male and female axSpA patients was most pronounced for <i>patient global</i> scores (Figure 2). Men reported a baseline patient global score of 4,3 (95% CI 3,8 – 4,8), compared to a score of 5,1 (95% CI 4,7 – 5,6) in women (p = 0,01). <h3>Conclusion</h3> Female axSpA patients report a significantly higher <i>patient global</i> score compared to men. This contributes to a significantly higher ASDAS-PRO in women. However, neither the ASDAS itself nor the ASDAS disease activity categories are significantly affected by gender contrasts in PRO. <h3>References</h3> [1] Lukas C, Landewe R, Sieper J, Dougados M, Davis J, Braun J, et al. Development of an ASAS-endorsed disease activity score (ASDAS) in patients with ankylosing spondylitis. Annals of the rheumatic diseases. 2009;68(1):18-24. [2] Machado PM, Landewe R, Heijde DV. Ankylosing Spondylitis Disease Activity Score (ASDAS): 2018 update of the nomenclature for disease activity states. Annals of the rheumatic diseases. 2018;77(10):1539-40. <h3>Disclosure of Interests</h3> Ann-Sophie De Craemer: None declared, Thomas Renson: None declared, Liselotte Deroo: None declared, Manouk de Hooge: None declared, Philippe Carron: None declared, Filip van den Bosch Consultant for: AbbVie, BMS, Galapagos, Janssen, Lilly, Merck, Novartis, Pfizer and UCB, Speakers bureau: AbbVie, BMS, Janssen, Lilly, Merck, Novartis, Pfizer and UCB., Dirk Elewaut: None declared