Predictive Validity of Parent-Reported PEDI-CAT Mobility and Gross Motor Function Measure in Children with Cerebral Palsy

Background: Recent contemporary studies demonstrated strong correlation between Gross Motor Function Measure (GMFM-66) and parent-reported Mobility domain of Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT Mobility) in children with Cerebral Palsy (CP). Hence, a need arose to investigate the prospect of predicting GMFM-66 scores using PEDI-CAT Mobility domain scores to estimate a child’s gross motor function score. Objectives: To examine the predictability of GMFM-66 scores using PEDI-CAT Mobility scores in children with CP at Gross Motor Function Classification System (GMFCS) levels II and III. Methods: GMFM-66 and PEDI-CAT Mobility scales were administered to 24 children with CP at GMFCS levels II and III. Pearson’s correlation coefficient was calculated and an association between the two scores was obtained. Regression analysis was done to predict GMFM-66 scores from the PEDI-CAT Mobility scores. Results: GMFM-66 scores and the PEDI-CAT Mobility scores showed strong positive correlation in children with CP [GMFCS level II (r = 0.876, p= 0.006); and GMFCS level III (r= 0.709, p<0.002)]. Regression analysis generated two equations for each level which were used to predict GMFM-66 scores from the PEDI-CAT Mobility scores. Conclusion: The association is strong between the two scores (GMFM-66 scores and PEDI-CAT Mobility scores). Hence, PEDI-CAT Mobility domain scores can be used to predict the corresponding GMFM-66 scores in children with CP at GMFCS levels II and III with moderate to high accuracy. Keywords: GMFM-66, PEDI-CAT Mobility, Cerebral Palsy, GMFCS