Drivers of cost and health-related quality of life in patients with systemic lupus erythematosus (SLE): a Swedish nationwide study based on patient reports

The objective of this paper is to investigate drivers of cost and health-related quality of life (HRQoL) related to disease activity and fatigue among patients with systemic lupus erythematous (SLE). A questionnaire was sent to members of a patient organization with a self-reported diagnosis of SLE, requesting information on demographics and disease characteristics, medications, resource utilization, informal care, loss of productivity, fatigue and HRQoL in relation to SLE. Mean annual costs per patient were estimated from a societal perspective. HRQoL was measured through EQ-5D and fatigue was measured through a 10cm VAS scale. Patient-reported disease activity was measured through the Systemic Lupus Activity Questionnaire (SLAQ) and corticosteroid dose. Drivers of costs and HRQoL were analyzed through regression analysis. A total of 339 patients out of 737 returned the questionnaire. Mean age was 55; 94% were female. The mean HRQoL measured through the five-item EQ-5D instrument was 0.64 and total costs were estimated at Euro22,594 (direct costs Euro7818; indirect costs Euro14,776). Disease activity, fatigue and corticosteroid doses had a statistically significant impact on costs and HRQoL. This study demonstrates that Swedish patients with SLE have low HRQoL and incur high societal costs and that are both associated with and most likely driven by disease activity, fatigue and corticosteroid use.