Ability of SLE-DAS and SLEDAI-2K to predict damage accrual in SLE: A real-world 7-year cohort study from Sweden

Abstract Objectives SLE remains a heterogeneous autoimmune disease that can lead to irreversible organ damage. SLE Disease Activity Score (SLE-DAS) is a recently developed tool with higher sensitivity to change than SLE Disease Activity Index-2000 (SLEDAI-2K). We compared SLE-DAS with other activity measures in terms of ability to predict organ damage. Methods Patients from Linköping University Hospital with ≥2 visits between 2008 and 2025 were included. SLEDAI-2K and Physician’s Global Assessment (PhGA) were assessed prospectively, and SLE-DAS retrospectively. Organ damage was estimated annually using the SLICC/ACR Damage Index (SDI). Adjusted mean scores of SLEDAI-2K (amSLEDAI-2K), PhGA (amPhGA), and SLE-DAS (amSLE-DAS) were determined for each time interval between consecutive visits, and their ability to predict damage accrual was evaluated using time-dependent multivariable Cox regression models. Predictive ability was compared across measures using Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). Results In total, 335 patients with 3582 outpatient visits contributed data. amSLE-DAS was an independent predictor of SDI increase at the 3- (HR; 95% CI: 1.04; 1.00–1.08), 5- (1.05; 1.01–1.09), and 7-year follow-up (1.04; 1.00–1.08). amSLEDAI-2K was predictive at the 5-year follow-up only (1.12; 1.02–1.22), and amPhGA at 5 (1.99; 1.19–3.36) and 7 (1.84; 1.02–3.30) years. amSLE-DAS showed a higher predictive ability for damage accrual than amSLEDAI-2K at the 3-, 5-, and 7-year follow-up, as indicated by lower AIC and BIC. Conclusion In this real-world Swedish setting, we demonstrate that SLE-DAS outperforms SLEDAI-2K in predicting organ damage accrual in SLE, substantiating its clinical relevance.