Influence of age at disease onset on future relapses and disability progression in patients with multiple sclerosis on immunomodulatory treatment.

Abstract

To investigate the relation of age at disease onset and clinical outcomes across the lifespan from adolescence in patients with multiple sclerosis (MS) on disease-modifying therapy (DMT). We analysed data from the Swiss Association for Joint Tasks of Health Insurers database containing data from 14718 patients with MS. Patients were included in this analysis when they were on DMT for at least 1year. The influence of age at disease onset on future relapses and disability worsening was explored usingmultivariable Cox proportional hazard regression models. Data from 9705 patients with MS were analysed. Pediatric-onset MSpatients (n=236) had higher relapse rates and marginally slower disability worsening rates compared with adult-onset MS (n=9469). The risk of relapses was highest in childhood and decreased continuously to about 35years of age. It remained stable for about a decade and then again continuously decreased. In contrast, disability worsening hazards remained stable from childhood to about 32years of age and then increased sharply around the age of 45years. Age is an important factor independentlyaffecting clinical outcomes in MS. This should be considered when designing clinical trials or choosing DMT.