Disease-Modifying Drug Uptake and Health Service Use in the Ageing MS Population

• Published in: Frontiers in immunology Vol. 12; p. 794075
• Main Authors: Ng, Huah Shin, Graf, Jonas, Zhu, Feng, Kingwell, Elaine, Aktas, Orhan, Albrecht, Philipp, Hartung, Hans-Peter, Meuth, Sven G, Evans, Charity, Fisk, John D, Marrie, Ruth Ann, Zhao, Yinshan, Tremlett, Helen
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 13.01.2022
• Subjects: Age Factors; Aged; Aged, 80 and over; ageing; Ambulatory Care; Antirheumatic Agents - therapeutic use; cohort studies; disease-modifying drugs; Drug Utilization - statistics & numerical data; Female; Follow-Up Studies; Geriatric Assessment; health services; hospitalization; Hospitalization - statistics & numerical data; Humans; Immunology; Male; Middle Aged; multiple sclerosis; Multiple Sclerosis - drug therapy; Multiple Sclerosis - epidemiology; Patient Acceptance of Health Care - statistics & numerical data; Public Health Surveillance; ageing; hospitalization; physician services; health services; multiple sclerosis; cohort studies; disease-modifying drugs
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2021.794075

Evidence regarding the efficacy or effectiveness of the disease-modifying drugs (DMDs) in the older multiple sclerosis (MS) population is scarce. This has contributed to a lack of evidence-based treatment recommendations for the ageing MS population in practice guidelines. We examined the relationship between age (<55 and ≥55 years), DMD exposure and health service use in the MS population. We conducted a population-based observational study using linked administrative health data from British Columbia, Canada. We selected all persons with MS and followed from the most recent of their first MS or demyelinating event, 18 birthday or 01-January-1996 (index date) until the earliest of emigration, death or 31-December-2017 (study end). We assessed DMD exposure status over time, initially as any versus no DMD, then by generation (first or second) and finally by each individual DMD. Age-specific analyses were conducted with all-cause hospitalizations and number of physician visits assessed using proportional means model and negative binomial regression with generalized estimating equations. We included 19,360 persons with MS (72% were women); 10,741/19,360 (56%) had ever reached their 55th birthday. Person-years of follow-up whilst aged <55 was 132,283, and 93,594 whilst aged ≥55. Any DMD, versus no DMD in the <55-year-olds was associated with a 23% lower hazard of hospitalization (adjusted hazard ratio, aHR0.77; 95%CI 0.72-0.82), but not in the ≥55-year-olds (aHR0.95; 95%CI 0.87-1.04). Similar patterns were observed for the first and second generation DMDs. Exposure to any (versus no) DMD was not associated with rates of physician visits in either age group (<55 years: adjusted rate ratio, aRR1.02; 95%CI 1.00-1.04 and ≥55 years: aRR1.00; 95%CI 0.96-1.03), but variation in aRR was observed across the individual DMDs. Our study showed beneficial effects of the DMDs used to treat MS on hospitalizations for those aged <55 at the time of exposure. In contrast, for individuals ≥55 years of age exposed to a DMD, the hazard of hospitalization was not significantly lowered. Our study contributes to the broader understanding of the potential benefits and risks of DMD use in the ageing MS population.