Assessing the Relationship Between Multidimensional Area-Level Indicators and Lupus Disease Activity in Children

Background/Objectives: Childhood-onset systemic lupus erythematosus (cSLE) is a chronic, multisystem autoimmune disease that is associated with more severe organ involvement, more intensive drug therapy, and increased long-term organ damage compared with adult-onset disease. The objectives of this study were to evaluate the performance of widely used small area-level multidimensional indicators of neighborhood disadvantage in a mixed urban-rural cSLE cohort against disease outcomes. Methods: This retrospective cohort study utilized electronic health records to identify and evaluate pediatric patients with cSLE across a single center in South Carolina between 1 January 2020 and 31 December 2024. Primary outcomes included disease activity at diagnosis, measured by Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K); the achievement of a low lupus disease activity state (LLDAS) by the last visit; the development of major organ involvement; and the rates of unplanned hospitalizations and emergency department visits. The associations of the census tract-level Area Deprivation Index (ADI), Social Vulnerability Index (SVI), and Childhood Opportunity Index (COI) with clinical presentation and outcomes were estimated using generalized linear models and logistic regression. Results: A total of 85 patients with cSLE were included, of which 76% reported being of Black race, and 28% lived in rural areas. Lupus disease severity was inconsistent across the metrics of area-level social vulnerability, neighborhood deprivation, child opportunity, and rurality. Patients who lived in more socially vulnerable communities were more likely to attain LLDAS during follow-up, while those who lived in lower-opportunity areas were more likely to develop CNS lupus. Baseline disease activity, renal involvement, and healthcare use were not significantly associated with area-level social disadvantages or rurality. Conclusions: In this single-center, mixed urban-rural cohort of children with cSLE, indicators of neighborhood-level disadvantage and rurality alone explained little variation in disease severity and disease control overall. The utility of available small area-level metrics is likely context-dependent and influenced by regional features, population characteristics, and the outcomes being studied. Future work should integrate individual- and area-level factors across diverse settings to better understand the drivers of health disparities.