A structured literature review of the direct costs of adult systemic lupus erythematosus in the US.

OBJECTIVE: A structured review of the literature was undertaken to examine the direct costs of adult systemic lupus erythematosus (SLE) in a US population.
METHODS: English-language studies published from January 2000 to April 2010 were systematically reviewed from both Medline's PubMed and the Cochrane databases. Studies were included if they reported direct medical costs of SLE among adults in the US.
RESULTS: Seven studies published since January 2000 that reported direct medical costs associated with SLE in the US were identified. Studies examined main cost categories of inpatient, outpatient, and pharmacy services; each contributed substantially to total costs. Wide SDs were reported, consistent with variability in disease manifestation. Mean annual direct costs of SLE patients ranged from $13,735-$20,926; the costs of those with and without nephritis ranged from $29,034-$62,651 and $12,273-$16,575, respectively. Across studies of a general SLE population, pharmaceutical costs composed 19-30% of total expenditures, with inpatient costs accounting for 16-50% and outpatient costs accounting for 24-56% of overall costs. Methodologies varied across studies, with patient self-reported resource utilization generating the lowest estimates versus claims-based analyses; Medicaid claims analyses generated lower incremental cost estimates for SLE patients versus control patients compared to estimates based on commercial claims analysis.
CONCLUSION: SLE is associated with substantial annual direct cost burden in the US; however, little research has been done examining costs associated with specific treatments or cost variation by disease severity and disease manifestations. Future research elucidating the causes in variation of costs will help in the appraisal of emerging therapies and in developing clinical management strategies.