Disability and Lack of Relapse in Multiple Sclerosis by Treatment Era

With today's highly effective therapies for patients with multiple sclerosis (MS), progression independent of relapse activity (PIRA) is increasingly recognized (NEJM JW Neurol May 24 2022 and JAMA Neurol 2022; 79:682). To evaluate the changes in the contribution of PIRA to disease burden over time, investigators evaluated disease characteristics in 1405 patients with relapsing-remitting MS from a single MS center in Italy. Patients were separated into groups by diagnosis year, with the eras categorized as 1980–1996, 1997–2008, and 2008–2022.

Patients from the earliest era had the highest mean baseline scores on the Expanded Disability Status Scale (EDSS), perhaps due to diagnosis later in the disease course or more-severe MS. The probabilit…