The increasing economic burden of multiple sclerosis by disability severity in Australia in 2017: results from updated and detailed data on types of costs

Background: Economic costs of Multiple Sclerosis (MS) in Australia were last estimated in 2010 and are likely to have changed over time, especially given this new era of increased access to higher efficacy disease modifying therapies (DMTs) with a strong focus on earlier MS diagnosis and treatment.

Objectives: To provide a comprehensive contemporary analysis of the updated direct and indirect costs of MS in Australia from a societal perspective and to examine how the cost landscape has changed overtime.

Methods: Costs were estimated from the 2016 Economic Impact Survey (EIS) of the Australian MS longitudinal Study (AMSLS) and were stratified by various (indirect and direct) cost categories/sub-categories and disability severity. Disability was assessed with the patient determined disease steps (PDDS) and mapped against the gold-standard Expanded Disability Status Scale (EDSS), and classified as no disability (EDSS level: 0), mild (EDSS 1-3.5), moderate (EDSS 4-6) and severe (EDSS 6.5-9.5). A generalized linear model (GLM) predicted covariate adjusted costs for each disability severity. All costs are presented in 2017 Australian dollars.

Results: 488 (15.5% of the 3,163) AMSLS participants completed the survey. Annual costs per person with MS increased 17% from 2010 to $68,382 in 2017, driven largely by increased direct costs (from $16,306 in 2010 to $30,346 in 2017) (particularly those related to DMTs, hospitalizations, consultations, and medical tests), but offset by decreased costs of lost wages (from $29,030 in 2010 to $21,858 in 2017) as a result of recent positive shifts in the employment landscape for Australians with MS. Costs increased with increasing disability severity: $30,561 (95% confidence intervals [CI]: $25,672-$35,451), $55,815 (95%CI: $47,503-$64,126), $76,915 (95%CI: $68,866-$84,964), and $114,813 (95%CI: $102,252-$127,374) for no, mild, moderate and severe disability, respectively. The differences in costs between the four disability groups remained statistically significant even after adjustment for age, sex, DMT usage status, disease course and areas of remoteness.

Conclusions: MS has an increasing economic burden in Australia. The study provides current economic data on MS in Australia that are important for policy development, priority setting and management of public health.