Reliability of GMFCS family report questionnaire

To examine the reliability of the web-based GMFCS Family Report Questionnaire (GMFCS-FR) between 8 and 11 years old children, compared with the GMFCS-Expanded and Revised (GMFCS-E&R).

The GMFCS-FR was translated from the English GMFCS-FR into Danish after the CanChild guidelines; only the order of levels was chosen like in the GMFCS-E&R. Families of 30 children with spastic and dystonic cerebral palsy (age from 8 to 11 years, randomly selected from a cerebral palsy register) answered the GMFCS-FR and were later interviewed by two physiotherapists. Participants and non-responders were compared on basic parameters available from the Danish CP register. Inter-rater agreement and weighted κ was calculated in order to compare the translated GMFCS-FR with physiotherapist's applied GMFCS-E&R.

The inter-rater agreement between the GMFCS-FR in Danish and the GMFCS-E&R was high (76%) and misclassification was minimal. There was a good agreement on the same or nearby levels (weighted κ = 0.76 and 0.81). The family rated the same or less ability, when compared with trained physiotherapists.

The GMFCS-FR is a reliable tool for GMFCS evaluation among 8-11 years old Danish children with CP. The tendency for less-ability rating by families is important when performing and comparing results from epidemiological studies based on GMFCS-FR and GMFCS-E&R.