OP0297 THE SLE-DAS ENABLES ACCURATE AND USER-FRIENDLY DEFINITIONS OF REMISSION AND CATEGORIES OF LUPUS DISEASE ACTIVITY: DERIVATION AND VALIDATION STUDY IN 1190 SLE PATIENTS

Background: Treatment of systemic lupus erythematosus (SLE) is tailored according to the intensity SLE disease activity and aims achieve remission. Current definitions remission categories are mostly based on Disease Activity Index (SLEDAI), which has important limitations. The Score (SLE-DAS) a validated continuous score with higher accuracy in measuring sensitivity-to-change as compared SLEDAI 1 . SLE-DAS user-friendly its online calculator. Objectives: To derive validate cut-off values for defining clinical state. Methods: Derivation study was conducted at Padova Lupus Clinic. Validation performed prospectively patients from Cochin Clinic by post-hoc analysis BLISS-76 ( NCT00410384 ) trial. Gold-standard state fulfillment Definition Of Remission In (DORIS). Clinics, time inclusion, senior clinician classified each patient presenting: (i) remission, (ii) mild, or (iii) moderate/severe activity. cut-offs using ROC curve against this expert classification. Performance these assessed with: classification (in cohort); British Isles Assessment Group (BILAG) index BLISS-76). An index-based Boolean definition were tested applying decision trees, CHAID (chi-square automatic interaction detection) algorithm their performance estimated. Results: We included 1190 (221 Padova, 150 819 cohorts). derivation cohort, best were: SLE-DAS≤2.08; mild activity, 2.08<SLE-DAS≤7.10; SLE-DAS>7.10. Table shows cut-offs. Boolean-based (all items scores = 0 prednisone ≤5mg/day) showed sensitivity specificity 100% (Padova) validation (Cochin) cohorts. (SLE-DAS ≤2.08 presented =100% =97.4% fully substantiated CHAID. 1. physician’s BILAG (n =1190). category Sensitivity (% Specificity Accuracy Cohort (SLE-DAS≤2.08) 99.3 97.1 98.6 Mild (2.08<SLE-DAS≤7.10) 74.2 98.9 95.5 Moderate Severe (SLE-DAS>7.10) 97.4 96.7 96.8 99.1 93.9 98.0 82.6 99.2 100.0 98.7 § vs. §§ (SLE-DAS≤7.10 >7.10) 91.4 84.1 90.8 Remission/Mild: No B A Moderate/severe: ≥1 Conclusion: an accurate easy use tool categories, both assessment BILAG. References: [1]Jesus D, et al. (SLE-DAS): new measure high changes Ann Rheum Dis 2019;78:365-71. Acknowledgements: authors would like thank GlaxoSmithKline (Uxbridge, UK) granting access data trial through Clinical Study Data Request consortium. Disclosure Interests: None declared