Late-onset MS is associated with an increased rate of reaching disability milestones

Abstract

Objective: To describe patient characteristics and assess the risk of disability worsening in patients of different age groups with focus on late-onset multiple sclerosis (LOMS) defined as disease onset after the age of 50 years.

Methods: The nationwide population-based Danish Multiple Sclerosis Registry served as data source. We described baseline characteristics and analyzed rates of reaching Expanded Disability Status Scale (EDSS) milestones.

Results: We identified 28,232 patients with MS with a known year of clinical onset, of which 2661 had LOMS. The LOMS group had a higher proportion of males and patients with primary progressive disease course, and they were less likely to receive disease-modifying therapy. The initial rate of reaching EDSS milestone 6 after diagnosis was higher in LOMS [hazard ratio (HR) 1.53; 95% confidence interval (CI) 1.14-2.06]; however, when assessing the risk of reaching EDSS 6 according to age, the HR was significantly lower for the LOMS group (HR 0.307; 95% CI 0.221-0.426).

Conclusion: The clinical characteristics and treatment approaches for patients with LOMS differ from their younger counterparts. Following diagnosis, patients with LOMS initially have an increased rate of reaching EDSS score 6; however, the risk of reaching EDSS score 6 at any given age is higher in patients with non-LOMS.

Keywords: Ageing; Disability; Late-onset; Multiple sclerosis; Real-word studies.