Related Experiment Video
Updated: Jun 3, 2026
The Multiple Sclerosis Performance Test (MSPT): An iPad-Based Disability Assessment Tool
Published on: June 30, 2014
Longitudinal measurement invariance of the Multiple Sclerosis Walking Scale-12
Robert W Motl1, Edward McAuley, Sean Mullen
1Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. robmotl@uiuc.edu
Objective:
One primary assumption underlying the unambiguous interpretation of change in Multiple Sclerosis Walking Scale-12 (MSWS-12) scores over time is longitudinal measurement invariance (i.e., Is the same construct being measured over time?). Such an assumption was tested in the present study over periods of 6 and 12 months in persons with relapsing-remitting multiple sclerosis (RRMS).
Method:
Participants completed a battery of questionnaires that included the MSWS-12 at baseline (n=269) and 6-months (n=260) and 12-months (n=252) follow-up. The data were analyzed using confirmatory factor analysis and a series of nested model comparisons in Mplus 3.0.
Results:
The results indicated that the unidimensional measurement model and all of its parameters (e.g., factor loadings and item intercepts) were invariant over periods of 6 and 12 months.
Conclusion:
We provide novel evidence that supports the unambiguous interpretation of scores from the MSWS-12 as a measure of change in walking impairment over time in a sample of persons with MS.
