Cost-of-illness studies in systemic lupus erythematosus: A systematic review.

OBJECTIVE: To summarize the state of knowledge regarding the economic burden of systemic lupus erythematosus (SLE) and to evaluate the quality of cost-of-illness (COI) studies conducted to date.

METHODS: Relevant literature was retrieved from the PubMed database in April 2010. The evaluation of identified articles was based on 7 key elements of COI studies derived from previous literature on health economics. Costs derived from each study were converted into 2008 US dollars using the Consumer Price Index and the purchasing power parity conversion rate.

RESULTS: A total of 11 articles were included in the evaluation. The average direct costs per patient-year ranged from $3,735-$14,410. Costs of inpatient care were found to be the largest component of direct costs in most of the studies. The employment rate varied from 35.8-55%. The average duration of annual short-term sick leave ranged from 7.0-64.8 days. The mean annual indirect costs per patient ranged from $1,093-$14,614, depending on the valuation method.

CONCLUSION: There is a substantial economic burden, in terms of health care resource utilization, associated with SLE, as well as losses of productivity due to work capacity impairment. The cost estimates in this review should be used with caution due to significant discrepancies in methodologies across studies. Future studies should address several methodologic considerations in order to measure the true costs related to SLE. Incidence-based COI studies are needed to evaluate the lifetime costs of SLE.