Understanding progression of disability in multiple sclerosis (MS) is essential to design preventive and therapeutic strategies.
We analyzed data from the Ausimmune Longitudinal (AusLong) Study to investigate the existing heterogeneity in long-term disability accumulation in a prospective cohort of People with MS (PwMS) followed over 10 years from the date of their first clinical diagnosis (FCD) and identify clinical and demographic factors associated with these trajectories.
We used a group-based trajectory model (GBTM) to measure the heterogeneity in the disability trajectories based on Expanded Disability Status Scale (EDSS) in a prospective cohort of 263 participants followed from FCD.
We identified three distinct clinically meaningful disability trajectories: no or mild, moderate and severe disability trajectories. Those in the minimal disability trajectory did not show any appreciable progression of disability (median EDSS ~ 1 at 10-year review), those in moderate and severe disability trajectories experienced disability worsening (median EDSS~ 2.5 and 6, respectively). The relative probability of being in a worsening disability trajectory was higher for older age at onset, those experiencing a higher number of relapses within five-year post FCD and those having a shorter interval between the first two attacks. High annual relapse rate was associated with an upward shift in moderate disability trajectory, whereas non-smoking status was associated with reducing the EDSS score in minimal and severe disability trajectories.
Those at highest risk of rapid disability progression can be identified based on their early clinical information with potential therapeutic implications.