Epidemiology and outcomes of emergency department visits in systemic lupus erythematosus: Insights from the nationwide emergency department sample (NEDS)

BACKGROUND: Systemic lupus erythematosus (SLE) patients are prone to frequent emergency department (ED) visits. This study explores the epidemiology and outcomes of ED visits by patients with SLE utilizing the Nationwide Emergency Department Sample (NEDS). METHODS: Using NEDS (2019), SLE ED visits identified using ICD-10 codes (M32. xx) were compared with non-SLE ED visits in terms of demographic and clinical features and primary diagnoses associated with the ED visits. Factors associated with inpatient admission were analyzed using logistic regression. Variations in ED visits by age and race were assessed. RESULTS: We identified 414,139 (0.35%) ED visits for adults ≥ 18 years with SLE. ED visits with SLE comprised more women, Black patients, ages 31–50 years, Medicare as the primary payer, and had higher comorbidity burden. A greater proportion of Black and Hispanic SLE patients who visited the ED were in the youngest age category of 18–30 years (around 20%) compared to White patients (less than 10%). Non-White patients had higher Medicaid utilization (27%–32% vs 19% in White patients). Comorbidity patterns varied based on race, with more White patients having higher rates of hyperlipidemia and ischemic heart disease (IHD) and more Black patients having chronic kidney disease (CKD), hypertension, and heart failure. Categorizing by race, SLE/connective tissue disease (CTD) and infection were the most prevalent primary ED diagnosis in non-White and White patients, respectively. Age ≥ 65 years, male sex, and comorbidities were linked to a higher risk of admission. Black race (OR 0.86, p = .01) and lowest income quartile (OR 0.78, p = .003) had lower odds of inpatient admission. CONCLUSION: Infection and SLE/CTD were among the top diagnoses associated with ED visits and inpatient admission. Despite comprising a significant proportion of SLE ED visits, Black patients had lower odds of admission. While the higher prevalence of older age groups, hyperlipidemia, and IHD among White patients may partly explain the disparate results, and further study is needed to understand the role of other factors including reliance on the ED for routine care compared among Black patients, differences in insurance coverage, and potential socioeconomic biases among healthcare providers.