Gross Motor Function Classification System in patients with cerebral palsy: interobserver reliability between parents and orthopaedic specialists

Background: The widely used Gross Motor Function Classification System (GMFCS) was designed to improve understanding and subsequent treatment of children with cerebral palsy. Previous studies investigating reliability between physician and family report of GMFCS have focused on limited age groups or mobility levels. The current study aims to investigate the GMFCS agreement between pediatric orthopaedic healthcare professionals (HCP) and families across all age groups for children with cerebral palsy. Methods: A total of 124 participants completed this prospective study at an orthopaedic children’s hospital. The HCP and family classified the mobility level of each child with cerebral palsy using the GMFCS. Each group was blinded to the other’s assessment of the child. Agreement reliability in GMFCS assessment between parents of children with cerebral palsy and HCP was determined. Results: The interclass correlation coefficient between parents and HCP was 0.92. There was agreement between HCP and parents in 69% of the children evaluated. These findings are similar to results of previous studies. Of those in which there was disagreement, 97% differed by one GMFCS level. In those that differed, the parents provided a lower functional level in 54%, in contrast to previous studies that reported much higher percentages. Conclusions: These findings add to the reliability of the GMFCS being used as a tool for effective communication between HCP and parents of those children with cerebral palsy across all age groups. This reliability can assist with the development of goals and expectations for that child.