Related Experiment Video
Updated: May 8, 2026
The Multiple Sclerosis Performance Test MSPT: An iPad-Based Disability Assessment Tool
Published on: June 30, 2014
Physical and psychological aspects of multiple sclerosis: Revisiting the Multiple Sclerosis Impact Scale (MSIS-29)
Carolyn A Young1,2, David J Rog3, Basil Sharrack4
1Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK.
Background:
The MSIS-29 measures the physical and psychological impact of MS.
Objective:
The associations between MSIS-29 domains and demographic/clinical aspects were examined and trajectories analysed over time.
Methods:
Data were collected in the Trajectories of Outcome in Neurological Conditions study for a diverse population of people with MS, with follow-up for up to 5 years. Following Rasch analysis, minimal important change (MIC) was computed for ensuing total, physical and psychological domains.
Results:
Fit to the Rasch model using data from 5921 participants validated physical, psychological and total domains, and the conversion table transforms raw scores to interval-level metric equivalents. These domains showed significant differences across demographic (age, gender, employment, education, and marital status) and clinical (subtype, treatment, and duration) factors with large effect sizes. The MIC scores were physical: 9.1, total: 14.1, which were both above measurement error, and psychological: 5.5 which was not, so 1.6% of participants reported psychological change which was clinically important but not statistically significant. Trajectory analysis showed three groups, one stable and two with significant slopes, improving and deteriorating.
Conclusion:
The MSIS-29 has shown adequate fit to the Rasch model after accommodating problems with local item dependency, through a bi-factor solution. The domains showed good discrimination across key factors.
Insights
The Multiple Sclerosis Impact Scale-29 (MSIS-29) effectively measures the physical and psychological effects of multiple sclerosis (MS). Analysis revealed significant demographic and clinical differences, with established minimal important change scores for physical and total domains.
Area of Science:
- Neurology
- Health Outcomes Research
- Psychometrics
Background:
- The Multiple Sclerosis Impact Scale-29 (MSIS-29) is a key instrument for assessing the physical and psychological burden of multiple sclerosis (MS).
- Understanding the psychometric properties and clinical meaningfulness of the MSIS-29 is crucial for effective patient management and research.
Purpose of the Study:
- To validate the MSIS-29 domains using Rasch analysis.
- To determine the associations between MSIS-29 domains and demographic/clinical factors.
- To establish minimal important change (MIC) scores and analyze outcome trajectories in people with MS.
Main Methods:
- Data from 5921 participants in the Trajectories of Outcome in Neurological Conditions study were analyzed.
- Rasch analysis was employed to validate the MSIS-29 domains (physical, psychological, total).
- Minimal important change (MIC) was computed, and trajectory analysis identified distinct patient groups.
Main Results:
- The MSIS-29 physical, psychological, and total domains demonstrated good fit to the Rasch model.
- Significant differences in MSIS-29 scores were observed across various demographic and clinical factors.
- MIC scores were established: physical (9.1), total (14.1), and psychological (5.5). Trajectory analysis identified stable, improving, and deteriorating groups.
Conclusions:
- The MSIS-29 is a validated instrument with good discriminative ability for assessing the impact of MS.
- The established MIC scores provide benchmarks for interpreting changes in patient-reported outcomes.
- Understanding patient trajectories aids in personalized care and intervention strategies for MS.
Related Concept Videos
01:22Self-Report Tests of Personality
01:19Multiple Sclerosis l: Introduction