(P-208) The Disease-modifying Drugs for Multiple Sclerosis and Subsequent Health Service Use: A Population-based Study

Background: Multiple sclerosis (MS) is a chronic disease of the central nervous system and has a lifetime societal costs greater than stroke or Alzheimer’s disease. Population-based longitudinal studies of healthcare use are needed to assess the benefits of the MS disease-modifying drugs (DMDs) and facilitate healthcare planning and funding decisions. Prior studies have not been population-based, have been limited to private health insurance enrollees, or were ecological in design and unable to assess DMD use at the individual patient level.

Objectives: We assessed the relationship between the exposure to a DMD for MS and health services use within a universal healthcare setting.

Methods: Adults with MS (aged ≥18 years) were identified using linked population-based health administrative data in four Canadian provinces (British Columbia, Manitoba, Nova Scotia and Saskatchewan) and were followed from the later of their first MS or demyelinating event or 01-January-1996 (index date) until the earliest of death, emigration or study end (31-December-2017 or 31-March-2018, depending on the province). Prescription records captured DMD exposure. Exposure was initially categorized as any DMD, then as first or second generation DMD, and finally by individual DMD. The association between these DMD exposure categories with subsequent all-cause hospitalizations and number of physician visits were examined using the recurrent events proportional means model and negative binomial regression, and reported as adjusted hazard ratios (aHR) and rate ratios.

Results: For 35,895 MS cases (72% women), the mean follow-up was 12.0 years. Person-years of DMD exposure were as follows: 63,290 person-years for any DMD, 54,605 person-years for any first-generation DMD and 8,685 person-years for any second-generation DMD. Any DMD, or any first-generation DMD exposure (versus no DMD exposure) were each associated with a 24% lower hazard of hospitalization (aHR:0.76; 95%CIs:0.71-0.82 for both comparisons). While any second-generation DMD (versus no DMD exposure) was associated with a 29% lower hazard (aHR:0.71; 95%CI:0.58-0.88), this lower hazard ranged from 18% for teriflunomide (aHR:0.82; 95%CI:0.67-1.00) to 44% for fingolimod (aHR:0.56; 95%CI:0.36-0.87). In contrast, DMD exposure (any, or by generation or individual DMD) was generally not associated with differences in the number of physician visits.

Conclusions: Our findings provide real-world evidence of a beneficial relationship between DMD exposure and hospitalizations. Fewer hospitalizations could represent a major healthcare cost avoidance and a lower disease burden for people with MS and their families.