To assess the association between early treatment and the risk of disability pension in patients with relapsing-remitting multiple sclerosis (RRMS). 

Using the nationwide Danish Multiple Sclerosis Registry, we included patients with an onset of RRMS from 1. January 1996 to 1. January 2016. After four years from onset, patients were categorized according to their first treatment start: Within 1 year of onset (early), between 1 and 4 years (intermediate) and from 4 to 8 years (late). Data on socioeconomic parameters were obtained by linkage to nationwide, population-based registries. We assessed the association between the timing of DMT start and the rate of disability pension using Cox regressions.

The cohort consisted of 5208 patients with 1922 early starters, 2126 intermediate starters and 1160 late starters. Age and sex were evenly distributed in all groups, mean age: 37 (SD: ±9) years and male-female ratio: 1:2. Mean EDSS at baseline differed slightly: Early: 1.5 (SD: ±1), Intermediate: 1.7 (SD: ±1) and Late: 1.9 (SD: ± 1). Baseline levels of education and cohabitation status were similar, but the share of patients receiving financial support differed: Early 34%, Intermediate 29% and Late 14%. Compared to early initiators, the rate of receiving disability pension was increased with increasing time from onset to start of DMT: Intermediate: HR 1.33 [95% CI: 1.09-1.63] and Late: HR 1.88 [95% CI: 1.48-2.39]. Further, the risk of receiving disability pension was associated with increasing EDSS, presence of chronic comorbidities and poor labor market affiliation.

Early treatment may postpone the time to disability pension. Our findings support guidelines with a focus on early treatment initiation and emphasizes the importance of early diagnosis.