Prevalence, Epidemiology, Mortality and Morbidity of Thrombotic Events in SLE: A Nationwide Study in the United States

Abstract

CONCLUSION Thrombotic events (TE) are a major cause of morbidity and mortality in patients with Systemic Lupus Erythematosus (SLE). Data is scant, however, on the prevalence, epidemiological characteristics, in hospital morbidity and mortality of TEs in this population. To perform a comprehensive epidemiological study on patients with SLE and DVT, PE or atypical thrombosis and their variation by gender, geographic region and hospital status. We also aimed to explore the associated morbidity and mortality for each TE and potential associations with other risk factors such as obesity and smoking. We conducted a retrospective cohort study, using the 2003-2018 Nationwide Inpatient Sample (NIS) database. All adult patients with a diagnosis of SLE using ICD-9 and 10 codes were included. The ICD 9 and 10 codes were also used to find other TE variables including DVT, PE, Cerebral venous sinus thrombosis (CVST), Splanchnic thrombosis (ST)and Arterial thrombosis (AT). Of the 513,904 SLE patients included, PE, DVT, ST, CVST and AT were identified in 1.38%, 3.07%, 1.34%, 0.04% and 0.35% patients respectively. Each TE (except CVST) had a statistically significant increase in length of hospital stay, cost of hospitalization and all-cause in-hospital mortality. Higher prevalence of PE, DVT, ST and AT were reported in males with SLE, and higher prevalence of obesity was seen in SLE patients with TEs, except AT, which interestingly was associated with a lower prevalence of obesity. Despite comprising only one third of the cohort, African Americans (AAs) faced the highest burden of PEs and DVTs. No significant differences were seen between geographic regions. This study is limited by administrative claims data, lack of antiphospholipid antibody status, and only includes inpatient encounters. Additionally, this is an observational retrospective study, and the assessment is limited to association of these thrombotic events in the SLE population. Arterial, venous and atypical thrombosis exert significant morbidity and mortality in patients with SLE. Racial and gender variations exist in each category of thrombosis, and identifying these differences is crucial while taking management decisions for patients with SLE. Particular attention should be directed to AAs with SLE, who appear to be particularly vulnerable.