Costs and quality of life by disability among people with multiple sclerosis: a register-based study in Sweden

BACKGROUND: Population-based estimates of costs of illness and health-related quality of life, by disability levels among people with multiple sclerosis, are lacking. OBJECTIVES: To estimate the annual costs of illness and health-related quality of life, by disability levels, among multiple sclerosis patients, 21–64 years of age. METHODS: Microdata from Swedish nationwide registers were linked to estimate the prevalence-based costs of illness in 2013, including direct costs (prescription drug use and specialised healthcare) and indirect costs (calculated using sick leave and disability pension), and health-related quality of life (estimated from the EQ-5D). Disability level was measured by the Expanded Disability Status Scale (EDSS). RESULTS: Among 8906 multiple sclerosis patients, EDSS 0.0–3.5 and 7.0–9.5 were associated with mean indirect costs of SEK 117,609 and 461,357, respectively, whereas direct costs were similar between the categories (SEK 117,423 and 102,714, respectively). Prescription drug costs represented 40% of the costs of illness among multiple sclerosis patients with low EDSS, while among patients with high EDSS more than 80% were indirect costs. Among the 1684 individuals who had reported both EQ-5D and EDSS, the lowest health-related quality of life scores were found among those with a high EDSS. CONCLUSION: Among people with multiple sclerosis, we confirmed higher costs and lower health-related quality of life in higher disability levels, in particular high indirect costs.