Reliability and validity of the GMFM-66 in 0- to 3-year-old children with cerebral palsy

Area of Science:

• Pediatric Neurology
• Rehabilitation Medicine
• Biostatistics

Background:

• Cerebral palsy (CP) significantly impacts gross motor function in children.
• Accurate assessment tools are crucial for monitoring development and intervention effectiveness.
• The Gross Motor Function Measure (GMFM) is widely used, but its suitability for very young children (<3 years) requires examination.

Purpose of the Study:

• To evaluate the reliability and validity of the 66-item Gross Motor Function Measure (GMFM-66) for assessing gross motor function in children under three years old with cerebral palsy.
• To compare the performance of the GMFM-66 with a newly developed 73-item version (GMFM-73) in this population.

Main Methods:

• Utilized data from 171 children with cerebral palsy (age range 3-36 months).
• Administered both the GMFM-88 and subsequently derived GMFM-66 and GMFM-73 versions.
• Assessed test-retest and interscorer reliability, and correlated scores and change scores between GMFM-66 and GMFM-73.

Main Results:

• The GMFM-66 demonstrated high test-retest (ICC=0.9666) and interscorer (ICC=0.9782) reliability.
• Strong correlations were observed between GMFM-66 and GMFM-73 scores (r=0.9848) and change scores (r=0.8700).
• The GMFM-73 offered only a marginal 14% gain in relative precision compared to the GMFM-66.

Conclusions:

• The GMFM-66 is a reliable and valid tool for assessing gross motor function in young children (<3 years) with cerebral palsy.
• The GMFM-73 did not provide significantly superior performance for this specific pediatric population compared to the GMFM-66.