Reasons for Hospitalization and In‐Hospital Mortality in Adult Systemic Lupus Erythematosus

OBJECTIVE: Systemic lupus erythematosus (SLE) is an autoimmune disease with an increased risk of hospitalization. Multiple studies have reported SLE flare, infection, and cardiovascular (CV) events as the most common reasons for hospitalization. The aim of this study was to use a large US population–based database to comprehensively analyze all indications for adult SLE hospitalization and reasons for in‐hospital mortality. METHODS: We conducted a retrospective study of SLE hospitalizations in 2017 from the National Inpatient Sample database. The “reason for hospitalization” and “reason for in‐hospital mortality” in patients with SLE were divided into 19 categories based on their principal International Classification of Diseases, Tenth Revision, Clinical Modification (ICD‐10) diagnosis. RESULTS: A total of 180 975 hospitalizations carried either a principal or secondary ICD‐10 code for SLE. The leading reasons for hospitalization were CV (16%), rheumatologic (13%), infectious (11%), respiratory (10%), and gastrointestinal (10%). SLE itself was the principal diagnosis in only 6% of the hospitalizations. In‐hospital death occurred in 1 of every 50 SLE hospitalizations. Infectious (37%) and CV diagnoses (21%) were the most common reasons for in‐hospital death, with sepsis being the most frequent reason for death. CONCLUSION: This analysis represents the only report to date that comprehensively categorizes the reasons for hospitalization and reasons for in‐hospital mortality of patients with SLE on a US national level. SLE itself was the principal diagnosis for only a small percentage of hospitalizations. CV diagnoses were the most common reason for hospitalization. In‐hospital death occurred in 1 of every 50 SLE hospitalizations. Infectious and CV diagnoses were the most common reason for in‐hospital death.