The costs associated with ankylosing spondylitis/axial spondyloarthritis in Aotearoa/New Zealand

Abstract

Aim To evaluate costs associated with a diagnosis of spondyloarthritis (SpA) in an Aotearoa/New Zealand cohort. Method Patients with SpA attending specialist SpA clinics in Auckland and Hamilton completed a series of questionnaires on costs associated with ankylosing spondylitis, disease parameters (BASDAI), work productivity (WPAI, WLQ) and quality of life measures (EQ-5D, ASAS-HI). Results Eighty-one patients (median age 43 years) completed the study. All fulfilled the ASAS criteria for axial spondyloarthritis and 44 (58%) fulfilled the Modified New York Criteria for ankylosing spondylitis. The mean (SD) score on the EQ-VAS was 69mm (24.1). More than half reported difficulties with usual activities and more than 80% had moderate pain or discomfort despite current treatment. Sixty-six (82%) were in the workforce, and the mean work productivity loss was 4.8%. The mean (SD) annual cost was NZ$15,677 (NZ$11,269) with NZ$12,189 direct cost and NZ$3,488 productivity loss. The largest cost driver was use of biologic medications, which were used by 48% patients. Conclusion This study has quantified the direct and indirect costs of spondyloarthritis (SpA) in Aotearoa/New Zealand, and demonstrates meaningful reduction in quality of life and work productivity in patients with SpA. The major driver of direct costs in SpA are biologic medications.