A168: Systemic Lupus Erythematosus In‐Hospital Mortality Risk Across Ages: A National Estimate

Abstract

Background/Purpose:Systemic lupus erythematosus (SLE) mortality rates in the U.S. have improved dramatically over the past 50 years, with estimated 5‐year survival rates in childhood‐onset SLE (cSLE) increasing from <50% to >95%. However, current mortality risk for hospitalized individuals with SLE across all age groups has not been described. The goal of this study was to assess mortality risk among hospitalized children and adults with SLE, and to compare these rates to age‐ and sex‐specific all‐cause mortality, using a nationwide hospital discharge dataset.Methods:Data derive from the 2011 National Inpatient Sample (NIS), the largest all‐payer inpatient health care database in the United States. The NIS contains all discharge data from more than 1,000 hospitals, which approximates a 20 percent stratified sample of all U.S. acute‐care non‐federal hospitals, including children's hospitals. All hospitalizations of non‐pregnant individuals age 5 years and older were included in the analysis. Lupus hospitalizations were identified by a discharge ICD‐9 diagnosis code of 710.0. We calculated age‐specific standardized mortality ratios (SMRs) to compare the risk of all‐cause in‐hospital mortality among individuals with SLE to the risk of in‐hospital mortality among all patients.Results:A total of 6,157,972 hospitalizations were included in the analysis, of which 39,635 carried a discharge diagnosis of SLE. Lupus hospitalizations included 242 hospitalizations of children age 5–14, 2,225 hospitalizations of youth age 15–24, and 4,610 hospitalizations of young adults age 25–34. Hospitalized individuals with SLE were younger (mean age 52 v. 61 years), more likely to be female (89% v. 53%), and less likely to be white (52% v. 71%). Among 148,507 deaths in the total sample, 709 carried a discharge diagnosis of SLE. There were no deaths among hospitalized children with SLE age 5–14, 14 deaths among youth age 15–24, and 54 deaths among young adults age 25–34. The SMR for hospitalizations of individuals with SLE was highest for ages 25–34 (2.3, 95% CI 1.7–3.0, Figure 1), followed by ages 15–24 (1.65, 95% CI 0.9–2.78), and 35–44 (1.4, 95% CI 1.1–1.9). Adults 45 or older with SLE did not have significantly elevated mortality risk. imageConclusion:In this large national dataset, there were no in‐hospital deaths among children under age 15 with SLE, which supports previous findings that mortality rates in childhood‐onset SLE have improved significantly. However, across all ages, young adults with SLE had the greatest excess mortality risk. It is not known whether these young adults have recent‐onset SLE, or longstanding cSLE. Further work is needed to unravel whether this excess mortality results from disease severity, disease damage, poor health care transitions or other factors.