Is the Symbol Digit Modalities Test a useful outcome in secondary progressive multiple sclerosis?

Abstract

It is unclear which cognitive outcome measure is the most useful for clinical trials in multiple sclerosis. To investigate the usefulness of the Symbol Digit Modalities Test (SDMT) as a clinical outcome measure in secondary progressive multiple sclerosis (SPMS), we describe the frequency of worsening and improvement events in a large randomized controlled trial (RCT) dataset.