Development and validation of a muscular dystrophy-specific functional rating scale.

Area of Science:

• Neurology
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Muscular dystrophy significantly impacts patient function.
• Existing scales may not fully capture the functional decline.
• A disease-specific, reliable measure is needed.

Purpose of the Study:

• To develop and validate a new rating scale for measuring the functional impact of muscular dystrophy.
• To create the Muscular Dystrophy Functional Rating Scale (MDFRS).

Main Methods:

• A three-stage development process including patient interviews, literature review, and expert opinion.
• Administered a preliminary scale to 85 patients and refined it into the 33-item MDFRS.
• Assessed measurement properties (reliability, validity, sensitivity) in 121 muscular dystrophy patients.

Main Results:

• The final 33-item MDFRS demonstrated excellent internal consistency (Cronbach's alpha 0.84–0.97).
• High test-retest and inter-rater reliability (ICC = 0.99) were confirmed.
• The MDFRS showed strong correlations with other functional scales and impairment parameters, with minimal floor/ceiling effects.

Conclusions:

• The Muscular Dystrophy Functional Rating Scale (MDFRS) is a reliable and valid disease-specific tool.
• It accurately assesses functional status in individuals with muscular dystrophy.
• The MDFRS is suitable for clinical and research applications.