Validity of minimal clinically important difference values for the multiple sclerosis walking scale-12?

Area of Science:

• Neurology
• Rehabilitation Science
• Clinical Measurement

Background:

• Interpreting meaningful change in multiple sclerosis (MS) walking is crucial for patient care.
• Proposed minimal clinically important difference (MCID) values for the Multiple Sclerosis Walking Scale-12 (MSWS-12) are 4 and 6 points.

Purpose of the Study:

• To evaluate the validity of 4- and 6-point MCID values for the MSWS-12.
• To determine if MSWS-12 MCID values correspond with changes in objective walking measures in persons with MS.

Main Methods:

• 82 individuals with MS completed the MSWS-12, timed 25-ft walk (T25FW), 6-min walk (6MW), gait analysis, and wore an accelerometer over 7 days, twice over 6 months.
• Participants were grouped into stable, improved, or worsened perceived walking based on 4- or 6-point MSWS-12 changes.
• Mixed-model ANOVAs compared changes in walking outcomes across groups.

Main Results:

• No statistically significant group-by-time interactions were found for T25FW, 6MW, gait analysis, or accelerometry.
• This indicates that the proposed MCID values for the MSWS-12 did not align with significant changes in objective walking performance.

Conclusions:

• The study did not confirm that 4- or 6-point MCID values for the MSWS-12 reflect meaningful changes in walking.
• Further research is needed to establish reliable MCID values for assessing walking improvements in MS.