Redefining the Multiple Sclerosis Severity Score (MSSS): The effect of sex and onset phenotype. (November 2020)

• Record Type: Journal Article
• Authors: Zhou, Yuan; Claflin, Suzi B; Stankovich, Jim; van der Mei, Ingrid; Simpson, Steve; Roxburgh, Richard H; Kalincik, Tomas; Blizzard, Leigh; Lugaresi, Alessandra; Alroughani, Raed; Sajedi, Seyed Aidin; Butzkueven, Helmut; Pucci, Eugenio; Spitaleri, Daniele LA; Granella, Franco; Cristiano, Edgardo; Yamout, Bassem; Hughes, Stella; Gouider, Riadh; Sánchez Menoyo, José Luis; Olascoaga, Javier; McGuigan, Chris; Shaw, Cameron; Kermode, Allan G; Kasa, Krisztian; Al-Harbi, Talal; Altintas, Ayse; Laureys, Guy; Fragoso, Yara; Hardy, Todd A; Csepany, Tunde; Sirbu, Carmen-Adella; Decoo, Danny; Sas, Attila; Alvarez-Cermeño, Jose C; Kotkata, Karim; Millán-Pascual, Jorge; Taylor, Bruce V;
• Is Part Of: Multiple sclerosis. Volume 26:Number 13(2020)
• Page Start: 1765
• Page End: 1774
• Publication Date: 2020-11
• Subjects: Multiple sclerosis -- Multiple Sclerosis Severity Score -- disability progression -- onset phenotype; Central nervous system -- Diseases -- Periodicals; Myelin sheath -- Diseases -- Periodicals; Inflammation -- Periodicals; Multiple sclerosis -- Periodicals; Central Nervous System Diseases -- Periodicals; Demyelinating Diseases -- Periodicals; Inflammation -- Periodicals; Multiple Sclerosis -- Periodicals; Système nerveux central -- Maladies -- Périodiques; Gaine de myéline -- Maladies -- Périodiques; Inflammation (Pathologie) -- Périodiques; Sclérose en plaques -- Périodiques; Electronic journals; 616.834005
• DOI: 10.1177/1352458519881994
• Languages: English
• ISSNs: 1352-4585

Abstract

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 with the same Expanded Disability Status Score (EDSS) and disease duration. When evaluated with a simulation, using an onset-specific MSSS improved statistical power in mixed cohorts. There were no significant differences by sex. Conclusion: The differences in the disability accrual rate between progressive- and relapsing-onset MS have a significant effect on MSSS. An onset-specific MSSS should be used when comparing the rate of disability progression among progressive-onset cases and for mixed cohorts.