Disease-modifying therapy use and health resource utilisation associated with multiple sclerosis over time: A retrospective cohort study from Alberta, Canada.

Background: Estimating multiple sclerosis (MS) prevalence and incidence, and assessing the utilisation of disease-modifying therapies (DMTs) and healthcare resources over time is critical to understanding the evolution of disease burden and impacts of therapies upon the healthcare system.

Methods: A retrospective population-based study was used to determine MS prevalence and incidence (2003-2019), and describe utilisation of DMTs (2009-2019) and healthcare resources (1998-2019) among people living with MS (pwMS) using administrative data in Alberta.

Results: Prevalence increased from 259 (95% confidence interval [CI]: 253-265) to 310 (95% CI: 304, 315) cases per 100,000 population, and incidence decreased from 21.2 (95% CI: 19.6-22.8) to 12.7 (95% CI: 11.7-13.8) cases per 100,000 population. The proportion of pwMS who received ≥1 DMT dispensation increased (24% to 31% annually); use of older platform injection therapies decreased, and newer oral-based, induction, and highly-effective therapies increased. The proportion of pwMS who had at least one MS-related physician, ambulatory, or tertiary clinic visits increased, and emergency department visits and hospitalizations decreased.

Conclusions: Alberta has one of the highest rates of MS globally. The proportion of pwMS who received DMTs and had outpatient visits increased, while acute care visits decreased over time. The landscape of MS care appears to be rapidly evolving in response to changes in disease burden and new highly-effective therapies.