BACKGROUND: Multiple sclerosis (MS) causes work disability and healthcare resource use, but little is known about the distribution of the associated costs to society.

OBJECTIVES: We estimated the cost of illness (COI) of working-aged individuals with MS, from the societal perspective, overall and in different groups.

METHODS: A population-based study was conducted, using data linked from several nationwide registers, on 14,077 individuals with MS, aged 20-64 years and living in Sweden. Prevalence-based direct and indirect costs in 2010 were calculated, including costs for prescription drug use, specialized healthcare, sick leave, and disability pension.

RESULTS: The estimated COI of all the MS patients were SEK 3950 million, of which 75% were indirect costs. MS was the main diagnosis for resource use, causing 38% of healthcare costs and 67% of indirect costs. The distribution of costs was skewed, in which less than 25% of the patients accounted for half the total COI.

CONCLUSIONS: Indirect costs contributed to approximately 75% of the estimated overall COI of MS patients of working age in Sweden. MS was the main diagnosis for more than half of the estimated COI in this patient group. Further studies are needed to gain knowledge on development of costs over time during the MS disease course.