Uitdehaag BMJ - Researchers sought to extend the findings of a prior analysis of relapsing-remitting MS (RRMS) trials published up to 2012 to assess if there has been a shift in outcome measures used to evaluate disability in phase III clinical trials in RRMS and progressive MS. They noted that, despite its well-recognized limitations, sustained Expanded Disability Status Scale (EDSS) worsening over brief time periods continued to be the most widely used measure of disability progression in pivotal MS trials. Hence this study highlights the necessity for a new toolset detecting the benefit of potential treatments, that slow (or reverse) progressive disability to be used in MS clinical trials.