RESUMO
OBJECTIVES: Motor function recovery is a key goal during rehabilitation of children and adolescents with traumatic brain injury. To evaluate how well treatment strategies improve motor function, we need validated outcome measures that are responsive to change in pediatric patients with traumatic brain injury. The Gross Motor Function Measure has demonstrated excellent psychometric properties in children with cerebral palsy and Down syndrome, yet its responsiveness in patients with pediatric traumatic brain injury has not been proven irrefutably. Our aim was to validate the Gross Motor Function Measure for this patient group. METHODS: Seventy-three patients (mean age: 11.4 years; range: 0.8-18.9 years) with moderate-to-severe traumatic brain injury were recruited in 12 rehabilitation centers and assessed twice with the Gross Motor Function Measure-88 over 4 to 6 weeks. As an external standard, we used judgements of change made independently by parents, physiotherapists, and 2 video assessors who were not familiar with the patients. We formulated and statistically investigated a priori hypotheses of how Gross Motor Function Measure change scores would correlate with those judgements of change. Both Gross Motor Function Measure versions, the original Gross Motor Function Measure-88 and the more recently developed Gross Motor Function Measure-66, were evaluated. RESULTS: Both Gross Motor Function Measure change scores correlated significantly with all of the clinical judgements of change. The degree of correlation that we postulated, that the Gross Motor Function Measure change score would correlate highest with the video rating followed by physiotherapists and parents, was fully confirmed by the Gross Motor Function Measure-88 and largely confirmed by the Gross Motor Function Measure-66. Both Gross Motor Function Measure versions revealed convincing discriminative capability. Test-retest reliability was excellent. CONCLUSIONS: We demonstrate convincing evidence of responsiveness and validity to support the use of both Gross Motor Function Measure versions as evaluative measures of gross motor function in children and adolescents with traumatic brain injury.