Agreement Between the Gross Motor Ability Estimator-2 and the Gross Motor Ability Estimator-3 in Young Children With Cerebral Palsy

Purpose:The purpose of this study was to determine the agreement between Gross Motor Ability Estimator-2 (GMAE-2) and Gross Motor Ability Estimator-3 (GMAE-3) calculations of Gross Motor Function Measure-66 (GMFM-66) scores in infants and young children with cerebral palsy.Methods:Data from 53 children 5 to 53 months of age were analyzed. Agreement between GMFM-66 scores using the GMAE-2 and the GMAE-3 was calculated using Bland-Altman plots and interclass correlation coefficients (ICCs). Eleven participants who had at least 1 GMFM-66 score of less than 25 using either method were identified for further analysis.Results:The average difference between GMFM-66 scores was 0.27 for all participants and 0.63 for the subset of lower-scoring participants. Good agreement was found for GMFM-66 scores for all participants (ICC = 0.998) and for subset of lower-scoring participants (ICC = 0.879).Conclusions:High levels of agreement exist between the GMAE-2 and the GMAE-3, which suggests that scores are comparable using either algorithm.