Abstract
OBJECTIVE: This study describes baseline demographics, clinical characteristics and treatments of patients diagnosed with systemic lupus erythematosus (SLE) at the time of registration in the registries of the Lupus Federated Data Network (LupusNet). METHODS: Data were collected from five SLE registries in four global regions: APLC (Asia Pacific), FORWARD (North America), RELESSER (Europe), GLADEL 2.0 and Almenara (Latin America). LupusNet uses a federated data network approach and a privacy-by-design method, where only aggregated results are shared. Demographics, disease activity (based on Physician Global Assessment (PGA) and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) scores), accumulated damage (Systemic Lupus International Collaborating Clinics Damage Index) and treatment use data were mapped and harmonised using the Observational Medical Outcomes Partnership Common Data Model V.5.4. RESULTS: A total of 10 370 patients were included in the analysis; of those, 3908 patients were in Asia Pacific, 3066 in North America, 1806 in Europe and 1590 in Latin America. The majority of patients were female (91%); the median (IQR) duration from SLE diagnosis to registry entry ranged from 5 (1-12) to 12 (6-19) years. Heterogeneity in disease activity was observed across registries based on mean (SD) SLEDAI-2K total (3.0 (4.1)-7.0 (7.4)) and PGA (0.4 (0.5)-1.2 (1.0)) scores. Across registries, SLE features most common were related to serologic activity (low complement and increased DNA binding (19%-47%)); other common clinical features included proteinuria and arthritis (4%-37%). Cataracts (4%-9%) were the most common characteristic related to accumulated damage. Glucocorticoids, antimalarials and immunosuppressants were the most commonly used treatments, with variations in their proportions observed across registries. CONCLUSIONS: These findings demonstrate significant heterogeneity in clinical characteristics and treatment patterns across the registries in LupusNet. By recognising regional differences, findings from LupusNet may help guide treatment approaches in SLE and optimise patient outcomes.