Background/Purpose:  Systemic lupus erythematosus (SLE) treatment comes at a high price, with both direct costs related to healthcare resource utilization and indirect ones related to decreased work productivity. Previous studies have attempted to estimate the annual medical costs of SLE patients in the United States using available Medicare datasets. This study was initiated to estimate health care costs to payers for SLE treatment at a major U.S. academic institution.

Methods: This is a retrospective cohort study evaluating healthcare utilization for patients with SLE treated at Columbia University Medical Center/NewYork-Presbyterian Hospital between January 2000 and September 2014, using electronic medical record (EMR) data from the Clinical Data Warehouse. The control groups are represented by patients with rheumatoid arthritis (RA) and patients with renal transplants. Patients with SLE, RA, or renal transplant were identified using diagnostic codes from the International Classification of Diseases, Ninth Revision (ICD-9). Data on diagnosis-related group (DRG) weighting was obtained from www.cms.gov; base rates for emergency and hospital visits were obtained from www.health.ny.gov.

Results:  4,800 hospitalized patients with SLE were identified based on one ICD-9 code for lupus. The diagnosis of SLE using these criteria was validated based on review of 134 charts; this method of identifying SLE cases in the Data Warehouse had a positive predictive value (PPV) of 0.66 for diagnosing SLE. A total of 5,642 patients with renal transplant, and 7,273 with RA were also identified. Reimbursement from payers for hospital admissions and ER visits were estimated from the DRG weights and base rates. The DRG provides a weighting system based on the severity of the average patient. For SLE and RA alone, the respective weight is 0.7882 and 0.7337; with a comorbid condition, it is 1.1645 and 1.2287. For SLE with a major comorbid condition, it is 2.4409, while the renal transplant weight is 3.154 regardless of comorbidities or severity.

Conclusion:  These data suggest that the cost to payers, health insurance companies, for hospital-based care for SLE (252.53 mil $) is higher than that for RA (182.8 mil $) despite the much higher prevalence of RA. However, the true cost of a lupus patient to the admitting hospital—especially a hospital that provides tertiary and quaternary care—can be much higher than what is reimbursed; it is likely closer to the cost of a transplant patient, as patients with moderate/severe SLE are treated with the same immunosuppressants as transplant recipients and are at risk for the same co-morbidities. In sum, these data suggest that SLE care in hospitals is expensive for health insurers. Further efforts should be made to improve outpatient management in order to reduce excessive use of emergency room resources, as has been done with the renal transplant population. Additionally, hospitals and providers should lobby for a revision of the DRG weights for SLE.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/estimated-cost-of-sle-hospitalizations/