Background/Purpose: Current literature characterizing the economic and clinical burden of systemic lupus erythematosus (SLE) is outdated and often does not consider SLE disease severity, which is associated with outcomes that may vary both within and across sub-populations. The objective of this study was to characterize a prevalence population of SLE and to assess outcomes related to comorbidities, healthcare resource utilization, and flares across disease severity levels and payer channels.

Methods: SLE patients were selected from IBM MarketScan Commercial Claims (COM), Medicare Supplemental (MDCR), and Medicaid (MDCD) Databases from 1/1/2013-3/31/2019. Inclusion criteria were 1) ≥1 inpatient claim with an SLE diagnosis or ≥2 non-diagnostic outpatient SLE claims with ≥1 rheumatologist or nephrologist specialty designation (index date set to random SLE claim with ≥12 months of SLE disease history preceding it), 2) continuous enrollment for 12 months pre-index, and 3) valid steroid Rx claims. SLE disease flares and severity were assessed using a published claims-based algorithm¹; patient characteristics, healthcare service use/costs, and flare outcomes were assessed during the year prior to index. All results were presented by disease severity and payer channel.

Results: 22,385 COM (23% mild; 44% moderate; 33% severe), 2,035 MDCR (20% mild; 39% moderate; 41% severe), and 8,191 MDCD (15% mild; 34% moderate; 51% severe) patients were included. Mean overall age was 46.5[11.5], 71.3[7.4], 40.9[12.2] years for COM, MDCR, and MDCD, respectively; older age was associated with an increase in disease severity for MDCD patients (p< 0.001). The majority of patients across all subgroups were female (88.2-93.3%) (Table 1). The mean Elixhauser Comorbidity Index was 0.5-2.0[3.9-0.6], which increased as SLE disease severity increased (p< 0.001). Common comorbidities included cardiovascular disease (20.7-63.1%), osteoarthritis (13.6-51.1%), and fatigue (10.7-23.0%). Across all payer channels, all-cause inpatient admissions increased significantly with disease severity (4.5%-9.2% mild; 9.9%-17.3% moderate; 24.2%-37.5% severe), with similar trends for emergency room utilization (17.6%-52.3% mild; 28.6%-66.6% moderate; 44.4%-77.7% severe; all p< 0.001) (Table 2). Total healthcare costs were 4-to-6-fold higher among patients with severe vs. mild disease ($29,354-68,253 among severe vs. $5,133-16,273 among mild; p< 0.001). Across all payer groups, the proportion of patients with a severe SLE flare, as well as the proportion of patients with 3+ flares, increased as disease severity also increased (Figure 1).

Conclusion: SLE-related comorbidities, disease flares, and healthcare expenditure vary by both disease severity and payer status. SLE patients with more severe SLE disease experience higher rates of comorbidities and SLE flares, which are associated with more intensive resource utilization and costs; Medicaid beneficiaries presented the highest use of ER and IP services. Overall, results demonstrate a potential unmet need in the SLE treatment landscape, especially among patients with more severe disease.

1. Garris C, et al. J Med Econ. 2013;16(5):667-677.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/clinical-and-economic-characterization-of-systemic-lupus-erythematosus-patients-real-world-observation-across-disease-severity-and-payer-channels-in-the-u-s/