SAT0664 RESPONSIVENESS OF PATIENT-REPORTED PHYSICAL FUNCTION OUTCOME MEASURES IN A REAL LIFE INTERNATIONAL COHORT OF 405 PATIENTS WITH PSORIATIC ARTHRITIS
Authors: Ying Ying Leung, Ana-Maria Orbai, Maarten de Wit, Andra Balanescu, Emmanuelle Dernis, Martin Soubrier, Lihi Eder, Josef S. Smolen, Laura C. Coates, Laure Gossec
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Physical function (PF) is a core domain to be measured in all trials for psoriatic arthritis (PsA); several instruments can be used but have not been compared. <h3>Objectives:</h3> To evaluate the longitudinal construct validities of 3 physical function patient-reported outcome measures (PF-PROMs): HAQ-disability index (HAQ-DI), physical functioning of SF12 (SF12-PF) and functional capacity of Psoriatic Arthritic Impact of Disease (PsAID-PF). <h3>Methods:</h3> The Remission/Flare in PsA (ReFlap) study (NCT03119805), is a prospective longitudinal study in 14 countries of consecutive adults with definite PsA collecting validated PsA outcomes. We assessed longitudinal construct validity using correlation between change scores of PF-PROMs with other assessments, according to <i>a priori</i> hypotheses. Responsiveness was assessed using the change of PF-PROMs anchored with patient-defined improvement/worsening at follow-up. We calculated the relative effectiveness statistic (RE=Standardized response mean, SRM<sup>2</sup> ratios) for each PF-PROM comparing improved/worsened groups vs. no change at follow-up. <h3>Results:</h3> Of 466 subjects recruited, 405 completed follow-up (50.8% male, mean(SD) age = 52.7 (12.6) years). After a mean (SD) follow-up of 4.3 (2.7) months, 27.6%, 55.0% and 17.4% reported improvement, no change and worsening. All change scores of the PF-PROMs met the <i>a priori</i> hypotheses (Table 1). PF-PROMs change scores were statistically different for improved and worse group from the no change group (p&lt;0.001). All PF-PROMs were more sensitive to worsening than improvement (Table 2). PsAID-PF was more sensitive to change compared to the other two PF-PROMs. <h3>Conclusion:</h3> Using data from this prospective longitudinal real-life study setting, HAQ-DI, SF12-PF and PsAID-PF fulfilled longitudinal construct validity for measurement of physical function in PsA. PsAID-PF had the highest responsiveness to change. These data will help to choose outcomes in PsA studies. <sup>δ</sup> determined by the best cut-off point using ROC curve; <sup>¶</sup> comparing to the no change group; **p&lt;0.001 by Kruskal-Wallis test; SD = standard deviation; SRM = standardized response means. <h3>Disclosure of Interests:</h3> Ying Ying Leung Grant/research support from: Abbvie, Novartis, Speakers bureau: Abbvie and Novartis, Speakers bureau: Novartis, Ana-Maria Orbai Grant/research support from: AbbVie, Celgene, Horizon Pharma, Janssen, Lilly, and Novartis, Consultant for: Lilly, Janssen, Novartis, Pfizer, and UCB, Maarten de Wit: None declared, Andra Balanescu Speakers bureau: multiple, Emmanuelle Dernis: None declared, Martin SOUBRIER: None declared, Lihi Eder Grant/research support from: AbbVie, Eli Lilly and Company, Amgen, Celgene, UCB, Janssen, Novartis, and Pfizer, Consultant for: AbbVie, Eli Lilly and Company, Amgen, Celgene, UCB, Janssen, Novartis, and Pfizer, Josef S. Smolen Grant/research support from: AbbVie, Eli Lilly, Janssen, MSD, Pfizer Inc, Roche, Consultant for: AbbVie, Amgen, AstraZeneca, Astro, Celgene, Celtrion, Eli Lilly, GlaxoSmithKline, ILTOO, Janssen, Medimmune, MSD, Novartis-Sandoz, Pfizer Inc, Roche, Samsung, Sanofi, UCB, Speakers bureau: AbbVie, Amgen, AstraZeneca, Astro, Celgene, Celtrion, Eli Lilly, GlaxoSmithKline, ILTOO, Janssen, Medimmune, MSD, Novartis-Sandoz, Pfizer Inc, Roche, Samsung, Sanofi, UCB, Laura C Coates Grant/research support from: AbbVie, Celgene, Lilly, Novartis and Pfizer, Consultant for: AbbVie, Amgen, BMS, Celgene, Galapagos, Gilead Sciences Inc., Janssen, Lilly, Novartis, Pfizer, Prothena Corp and UCB, Laure Gossec Grant/research support from: AbbVie, BMS, Celgene, Janssen, Lilly, MSD, Novartis-Sandoz, Pfizer, Sanofi, and UCB, Consultant for: AbbVie, Biogen, BMS, Celgene, Janssen, Lilly, MSD, Nordic Pharma, Novartis-Sandoz, Pfizer, Roche, Sanofi, and UCB, Consultant for: L Gossec has received honoraria from Celgene as investigator for this study