Evaluating the responsiveness of 2 versions of the gross motor function measure for children with cerebral palsy

Abstract

Objective: To compare the responsiveness to motor change of the original version of Gross Motor Function Measure (GMFM-88) and its second version (GMFM-66) in children with cerebral palsy (CP).

Design: Cross-sectional study.

Setting: Seven rehabilitation pediatric clinics.

Participants: Sixty-five children with CP (age range, 0.5-9.4y; mean, 3.7+/-1.9y) were recruited.

Intervention: The children's motor ability was assessed twice with a mean interval of 3.5 months using all of the GMFM-88 items. A 3-category range of therapist judgments on the children's meaningful motor improvement was used as an external standard.

Main outcome measures: GMFM-88 scores, GMFM-66 scores, and therapists' judgments.

Results: Regarding the association with the therapist judgments, the overall responsiveness of GMFM-66 is superior to that of GMFM-88. Both measures' sensitivities of the responsiveness are similar, but GMFM-66 has better specificity.

Conclusions: To evaluate the motor change in a sample of children with CP over a mean interval of 3.5 months by using the 2 versions of GMFM, the GMFM-66 was more responsive than the GMFM-88 with respect to consistency with therapist clinically meaningful judgments.