Reliability of GMFCS family report questionnaire

Abstract

Purpose: 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). Method: 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. Results: 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. Conclusion: 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.

Implications for Rehabilitation

• GMFCS Family Report Questionnaire for 6 to 12 years old children is a reliable tool for GMFCS evaluation of children with cerebral palsy.

• The tendency for less-ability rating by families, compared to rating by physiotherapist, is important for applying GMFCS in epidemiological studies on cerebral palsy.

Keywords::

• Cerebral palsy
• Danish GMFCS
• family report questionnaire
• GMFCS
• GMFCS-E&R

Acknowledgements

We thank the participating families, physiotherapists Annette Sandahl and Christa Lange for interviewing them, statistician Claus Sværke from Aarhus University for his advice in statistical analysis, physiotherapist Stine Stensgaard for translation and the co-workers in Danish Cerebral Palsy Registry for maintaining the database.

Declaration of interest: The first author was supported by a grant from Central Denmark Region and funding from the Augustinus Fund, the Dagmar Marshalls Fund, and the Civil Engineer Frode V. Nyegaard’s and His Wife’s Fund. The funding institutions had no influence on the interpretation of the results.