Costs and quality of life of patients with ankylosing spondylitis in Hong Kong

Abstract
Objectives. To assess the annual direct, indirect and total societal costs, quality of life (QoL) of AS in a Chinese population in Hong Kong and determine the cost determinants. Methods. A retrospective, non-randomized, cross-sectional study was performed in a cohort of 145 patients with AS in Hong Kong. Participants completed questionnaires on sociodemographics, work status and out-of-pocket expenses. Health resources consumption was recorded by chart review. Functional impairment and disease activity were measured using the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), respectively. Patients’ QoL was assessed using the Short Form-36 (SF-36). Results. The mean age of the patients was 40 yrs with mean disease duration of 10 yrs. The mean BASDAI score was 4.7 and BASFI score was 3.3. Annual total costs averaged USD 9120. Direct costs accounted for 38% of the total costs while indirect costs accounted for 62%. Costs of technical examinations represented the largest proportion of total cost. Patients with AS reported significantly impaired QoL. Functional impairment became the major cost driver of direct costs and total costs. Conclusion. There is a substantial societal cost related to the treatment of AS in Hong Kong. Functional impairment is the most important cost driver. Treatments that reduce functional impairment may be effective to decrease the costs of AS and improve the patient's QoL, and ease the pressure on the healthcare system.