Factors associated with clinically significant increased walking time in multiple sclerosis: Results of a survival analysis of short-term follow-up data from a clinical database. (April 2015)

• Record Type: Journal Article
• Authors: Miller, Deborah M; Thompson, Nicolas R; Cohen, Jeffrey A; Fox, Robert J; Hartman, Jen; Schwetz, Kathleen; Conway, Devon S; Rudick, Richard A
• Is Part Of: Multiple sclerosis. Volume 21:Number 4(2015)
• Page Start: 457
• Page End: 465
• Publication Date: 2015-04
• Subjects: Multiple sclerosis -- timed 25-foot walk test -- disease progression -- electronic health record -- accelerated failure time -- survival analysis; 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: 10.1177/1352458514544536
• Languages: English
• ISSNs: 1352-4585

Abstract

Background: Because multiple sclerosis (MS) is variable and unpredictable, if symptom worsening could be predicted, patients may feel better prepared to manage changes in function. Objective: The objective of this paper is to study the prediction of walking impairment in MS. Methods: We retrieved data for all MS patients at our center (2008–2009), including baseline and follow-up timed 25-foot walk (T25FW) times. We assessed the incidence of ≥20% worsening in T25FW by developing two survival models: (1) disease course and (2) Multiple Sclerosis Performance Scales (MSPS) score. The outcome was days until ≥20% worsening in T25FW. Covariates were disease subtype, years since diagnosis, Patient Health Questionnaire-9 (PHQ-9) score, and demographics. Data were interval censored; missing data were handled with multiple imputation. Results: Of 1544 patients, 309 (20%) experienced ≥20% worsening T25FW. For disease course, time to worsening was significantly shorter for secondary progressive vs. relapsing–remitting disease ( p < 0.001). For MSPS, patients with lower baseline MSPS scores progressed more slowly ( p = 0.001). In both models, sex, baseline T25W, and time since diagnosis were significantly associated with worsening. In the disease course model, PHQ 9 score may be related to worsening ( p = 0.07). Conclusion: These findings suggest factors associated with worsening in T25FW and a potential approach to establishing indicators associated with clinically significant change.