Rasch analysis to evaluate the motor function measure for patients with facioscapulohumeral muscular dystrophy.
Karlien Mul, Corinne G C Horlings, Catharina G Faber and 2 others
PMID 33165002WHAT IT FOUND
The Motor Function Measure is too easy for many patients with facioscapulohumeral muscular dystrophy.
It fails to distinguish between those with mild weakness and those with severe disability, so it may not accurately track progression or treatment response in this group.
Key findings
01The total Motor Function Measure did not fit the statistical model required for accurate measurement in patients with facioscapulohumeral muscular dystrophy.
02Most items in the axial/proximal and distal domains were too easy for the patients, resulting in large ceiling effects where many scored the maximum.
03Examiners struggled to discriminate between the response options for many items, indicating the scale's scoring system is not well-suited for this condition.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
This was a single-center study, so the results may not generalize to all populations with facioscapulohumeral muscular dystrophy, although the authors state the cohort was representative. The analysis was cross-sectional; patients were assessed only once, so the study could not evaluate the scale's stability over time (test-retest reliability). The study focused on the metric properties of the scale using Rasch analysis, which is a statistical evaluation, rather than a direct comparison against a gold-standard clinical assessment of change.
Declared interests
The authors declared no conflicts of interest.
The easy way to misread this
Do not assume the Motor Function Measure is invalid for all neuromuscular diseases. This study specifically shows it is unsuitable for facioscapulohumeral muscular dystrophy because the tasks are too easy for this group. It may still be appropriate for conditions with more severe or different patterns of weakness.