Clinical and economic characterization of mild, moderate, and severe systemic lupus erythematosus: Real-world observation across payer channels in the United States

BACKGROUND: Systemic lupus erythemato-sus (SLE) is a chronic autoimmune disease affecting as many as 322,000 people in the United States. Because of heterogeneity in both disease course and clinical manifes-tations, it is critical to identify a prevalent SLE population that includes patients with moderate or severe disease. Additionally, dif-ferences in the clinical and economic burden of SLE may exist across payer channels, yet to date this has not been reported in any pre-vious studies.OBJECTIVE: To characterize the clinical and economic burden of SLE across disease severity and payer channels.METHODS: This retrospective study includ-ed patients from Merative MarketScan Commercial, Medicare Supplemental, and Medicaid databases from 2013 to 2020 (Commercial/Medicare) or 2013 to 2019 (Medicaid), with at least 1 inpatient or at least 2 outpatient SLE claims and no invalid steroid claims. The index date was a random SLE claim with at least 12 months of disease history. Patients were continuously enrolled 1 year pre-index (baseline) and 1 year post -index and classified with mild, moderate, or severe disease using a published algorithm. Baseline demographics, clinical charac-teristics, flares, and utilization/costs were compared across disease severity.RESULTS: 22,385 Commercial, 2,035 Medicare, and 8,083 Medicaid patients had SLE. Most Medicaid patients (51.1%) had severe disease. Comorbidity scores increased with disease severity (P <0.001). 30.7% of Commercial, 34.1% Medicare, and 51.3% Medicaid patients had opioids, which increased with disease severity (P <0.001). All-cause costs ranged from 1.8-to 2.3-fold for moderate vs mild and 4.2-to 6.5-fold for severe vs mild. Outpatient medical costs accounted for the highest proportion of all -cause costs, except Medicaid patients with severe disease, for whom inpatient costs were highest. Mean (SD) SLE-related annual costs were $23,030 (43,304) vs $1,738 (4,427) in severe vs mild for Commercial, $12,264 (31,896) vs $2,024 (4,998) for Medicare, and $7,572 (27,719) vs $787 (3,797) for Medicaid (P < 0.001). For patients with severe disease in Medicaid, 16.5% and 60.1% had inpatient and emergency depart-ment (ED) visits, respectively, vs 10.3% and 26.5% Commercial vs 10.6% and 24.6% Medicare. Mean [SD] flares per year in the baseline period increased from 2.5 [1.7] in mild to 4.6 [1.9] in severe for Commercial, 3.2 [1.9] to 5.0 [2.1] for Medicare, and 2.0 [1.6] to 4.5 [2.0] for Medicaid.CONCLUSIONS: Patients with severe SLE experienced more comorbidities, flares, and utilization/costs. Outpatient costs were the largest driver of all-cause costs for Commercial and Medicare (and Medicaid for mild to moderate SLE). Medicaid beneficiaries had the highest rate of severe SLE, highest use of ED and inpatient services, and highest oral corticosteroid and opioid use but the lowest utiliza-tion of disease-modifying treatments. Results demonstrate an unmet need in SLE treatment, especially among patients with moderate to severe disease or Medicaid coverage.