An investigation of clinical outcome measures in PPMS to inform the design of investigator initiated clinical trials.

In this research project, we will determine the proportion of progressed patients by comparing baseline and follow-up disability measures. Patients missing the disability measure at baseline, the time point of interest, or the corresponding confirmation assessment (at either 3 or at 6 months) will be excluded from the analysis. Disability progression is defined as a 20% or more worsening from baseline in the time for the T25FW and the 9HPT, and according to the trial definition for the EDSS.We will determine these proportions of worsened patients for all outcome measures and their combinations, and for all time points these disability measures were used.This part of the analysis will inform the choice of the most useful primary outcome measure for trials in PPMS.In addition to this, we will use binary logistic regression models to investigate the association of baseline characteristics (sex, age, MRI characteristics at baseline, disability measures at baseline) with the risk of worsening throughout the trial. The association of each predictor variable to the risk of worsening will be expressed as an Odds ratio with its corresponding 95% confidence interval.