Redefining the Multiple Sclerosis Severity Score (MSSS): The effect of sex and onset phenotype (original) (raw)

2019, Multiple Sclerosis Journal

Background: The Multiple Sclerosis Severity Score (MSSS) is a widely used measure of the disability progression rate. However, the global MSSS may not be the best basis for comparison between all patient groups. Objective: We evaluated sex-specific and onset phenotype–specific MSSS matrices to determine if they were more effective than the global MSSS as a basis for comparison within these subsets. Methods: Using a large international dataset of multiple sclerosis (MS) patient records and the original MSSS algorithm, we constructed global, sex-specific and onset phenotype–specific MSSS matrices. We compared matrices using permutation analysis. Results: Our final dataset included 30,203 MS cases, with 28.9% males and 6.5% progressive-onset cases. Our global MSSS matrix did not differ from previously published data ( p > 0.05). The progressive-onset-specific matrix differed significantly from the relapsing-onset-specific matrix ( p < 0.001), with lower MSSS attributed to cases w...