Costs associated with severe and nonsevere systemic lupus erythematosus in Canada.

OBJECTIVE: To evaluate the annual direct medical cost of systemic lupus erythematosus (SLE) in Canada by disease severity and to estimate the incremental cost associated with disease severity and flares.
METHODS: Medical charts of consecutive patients seen in 3 SLE-specialized treatment centers between July 2007 and June 2008 were retrospectively assessed for disease severity at baseline and for disease activity and health care resource utilization over the following 2 years (±6 months). Annual cost was stratified by disease severity at baseline. Two-year cost was compared for patients with and without flares over 2 years. Multiple linear regression was used to determine the associations between annual cost and SLE severity, and between 2-year cost and the number and type of flare (mild/moderate versus severe).
RESULTS: A total of 109 active SLE patients (94% women, mean age 41.4 years, mean disease duration 11.3 years, 56 patients with severe disease) were studied. The average annual direct medical cost was $10,608 Canadian (2010 dollars) and was higher for patients with severe disease, $15,048 versus $5,917 (P < 0.001). The 2-year direct cost for patients with at least 1 flare was $22,633 versus $11,113 (P = 0.028) for patients without flares. The mean incremental annual cost was $7,007 (95% confidence interval [95% CI] $3,487, $13,048) for an SLE patient with severe disease, and the 2-year mean incremental cost was $5,848 (95% CI $2,919, $8,777) for each additional severe flare.
CONCLUSION: The direct health care cost of SLE patients in Canada is influenced by disease severity and the type and frequency of flares.