PMS64 ASSESSING THE QUALITY OF BIOLOGIC SWITCH DECISIONS IN PSORIATIC ARTHRITIS: VALIDATION OF PASQAL - AN OUTCOMES MEASUREMENT TOOL

Abstract

Switching between biologics is a recommended strategy for Psoriatic Arthritis (PsA), with the target being remission or low disease activity, and improved disease management. Biologic switch assessment is therefore of utmost relevance in order to maximize outcomes. This study aims to validate an outcomes measurement tool named PASQAL (Psoriatic Arthritis Switch Quality Assessment tooL). PASQAL was recently created to evaluate the quality of biologic switch in PsA patients with peripheral (pPASQAL) and axial (axPASQAL) phenotypes. For PASQAL’s validation, 12 experienced rheumatologists were asked to evaluate and classify the biologic switch of 80 clinical cases (40 with peripheral PsA and 40 with axial PsA). Clinical judgement was defined as the “gold standard” against which the tools’ output was compared. Each clinical case was evaluated by 3 experts and only those with consensual clinical judgement (agreement between at least 2 out of 3 rheumatologists) were included in the validation analysis. The results were used to assess its validity, through sensitivity/specificity analysis, and reliability, through the level of agreement between the tool and the clinical judgement measured by Cohen’s kappa. 75%(30/40) of peripheral PsA and 63%(25/40) of axial PsA switch scenarios reached agreement between rheumatologists and were, therefore, used for PASQAL’s validation. pPASQAL and axPASQAL were more sensitive upon “Good” quality level (92% and 100%), while more specific for the “Insufficient” quality level (97% and 100%). Concerning reliability, good agreement levels were obtained for both tools (k=0.87 pPASQAL;k=0.71 axPASQAL). PASQAL aims for higher standards of care, given that the likelihood of classifying a given switch as “Good” is lower than the rheumatologists’ classification (-25% to -33%). PASQAL’s validation provided evidence regarding tools’ validity and reliability for both phenotypes. These fully developed and validated tools may support rheumatologists in making more informed therapeutic decisions and be used on real-world research.