Background/Purpose: Venous thromboembolism (VTE) is a major cause of mortality and morbidity in hospitalized patients. Hospitalized patients with autoimmune disorders are particularly at risk of VTE. ÒNational Inpatient SampleÓ database was analyzed to determine trends in rate of hospitalization and mortality from VTE in hospitalized systemic lupus erythematosus (SLE) patients to assess its impact.

Methods: 2003-2011 National Inpatient Sample database of Healthcare Cost and Utilization Project was queried to identify all adults (age ³ 18 years) with SLE. SLE patients hospitalized with VTE as one of the top three diagnoses were identified. Demographic characteristics and in-hospital outcomes of this population were compared to SLE patients without a VTE diagnosis. Multivariate logistic regression analysis was used to obtain adjusted odds ratio (OR).

Results: The total number of hospitalized patients with SLE was 299,595 of which 6266 (2.09%) had VTE. Mean age of the study population was 51 years of and 89% were females. Mean age of SLE patients with VTE was lower than those without VTE (49 vs 51 years). Rate of VTE was higher in African Americans as compared to Caucasians or Hispanics (2.5% vs 2.0%) and in males when compared to females (2.9% vs 2.0%).

After adjusting for potential confounders, compared to those without VTE, SLE patients with VTE had significantly higher inpatient mortality (2.6% vs. 2.0%, OR 1.22 (CI 1.12 – 1.13, p = .001), longer length of stay (LOS) (5 vs. 4 days, OR 2.29 (CI 2.23 – 2.35), p < .001) and higher cost of hospitalization ($26000 vs. $20000, OR 1.46 (CI 1.39 – 1.55), p < .001), greater disability at discharge (OR 1.31 (CI 1.27 – 1.35), p < .001) (Table 1).

Conclusion: VTE in hospitalized patients with SLE is associated with significantly higher inpatient mortality, greater disability at discharge, increased length of stay and higher cost of hospitalization.  In this database patients with SLE and VTE were younger. Male sex and African-American race may be associated with an increased risk of VTE in patients with SLE. This cross-sectional study would help in the development and implementation of appropriate prophylactic strategies in high risk SLE population. Further studies are needed to understand the effect of autoimmune diseases on VTE risk among hospitalized patients.

References:

1. Yusuf HR et al. J Thromb Thrombolysis. 2014 Oct;38(3):306-13.

2. Healthcare cost and utilization project: overview of the Nationwide Inpatient Sample (NIS). URL: http://www.hcup-us.ahrq.gov/ 
nisoverview.jsp.