Streamlined EDSS for use in multiple sclerosis clinical practice: Development and cross-sectional comparison to EDSS

Background: The Expanded Disability Status Scale (EDSS) is the standard measure of disability in multiple sclerosis clinical trials. The EDSS has limited application in the clinical setting due to required completion time and scoring complexity. Systematically recording an objective, simplified, less time-intensive, and neurologist-derived disability score would be beneficial for patient care. Objective: To develop and validate a streamlined version of the Expanded Disability Status Scale (sEDSS) for clinical monitoring. Methods: The EDSS was modified by eliminating maneuvers with no impact on function, consolidating redundancies, and simplifying scoring. This sEDSS was refined and preliminarily validated using a pilot cohort of 102 patients. Subsequently, the sEDSS was retrospectively validated using 968 patients from the CombiRx trial. We evaluated correlation and agreement between each functional system as well as the overall sEDSS and EDSS. Results: The sEDSS correlated strongly with the EDSS, both overall (Spearman’s rho = 0.93) and for each functional system (Spearman’s rho 0.65–0.97). Correlation was slightly lower for functional systems where scoring was modified for consolidation and simplification. Conclusion: The sEDSS had strong agreement and correlation with the existing EDSS and can provide a useful measure of disability in clinical practice.