Trajectories of processing speed, disability, and their connections, over the years following disease modulatory treatment initiation among relapsing-remitting multiple sclerosis patients

• Introduction: Data on how processing speed of relapsing-remitting multiple sclerosis patients (RRMS) evolve over time and its association with disability progression is scarce. We analysed the COMparison Between All immunoTherapies for Multiple Sclerosis (CombatMS; NCT03193866), a nationwide observational drug trial in RRMS.Objectives: Identify trajectories of processing speed and disability and their connections after disease modulatory treatment (DMT) start within the RRMS population.Describe patient characteristics associated with trajectory groups.Aim: Model trajectories of processing speed and disability.Methods: We assessed trajectories of oral Symbol Digit Modalities Test (SDMT) and expanded disability status scale (EDSS) from first DMT start using a group-based modeling approach among 1,800 RRMS patients followed 2010-2021. We investigated predictors of trajectories using group membership assignments as a multinomial outcome and calculated conditional probabilities linking membership across the trajectories.Results: We identified four trajectories of processing speed: low SDMT score (mean starting values; MSV=36.7, standard deviation; SD=8.4)-stable (13%), medium score (MSV =50.8, SD=6.7)-minor decrease (52%), medium/high score (MSV=62.9, SD=8.6)-minor decrease (32%), and high score (MSV= 75.2, SD=9.7)-moderate decrease (3%), and four trajectories of disability: no disability-stable (23%), minimal signs-minor increase (45%), minimal disability-moderate increase (27%), and relatively severe disability-moderate increase (5%). Patients with natalizumab as first DMT were less likely to belong to the medium and high processing speed trajectories, relative to the low SDMT score-stable one. Sex, age at DMT start, and geographical region of treatment were associated with medium and high processing speed and with minimal signs and minimal dis-ability trajectories.There was 0% probability of belonging to the relatively severe disability-moderate increase EDSS trajectory if belonging to the high score-moderate decrease SDMT trajectory, and 8% probability of belonging to the no disability-stable EDSS trajectory if belonging to the low score-stable SDMT trajectory.Conclusions: Patients with lower SDMT scores at DMT start did not decline over the years, whereas those with minimal or relatively severe disability moderately lost function. Our results also suggest an inverse link between processing speed and disability trajectories after DMT start.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Neurologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Neurology (hsv//eng)

Publication and Content Type

vet (subject category)

art (subject category)