Validity and reliability of the Dutch language version of the Communication Function Classification System (CFCS-NL)

AIM The Communication Function Classification System (CFCS) is currently being developed by Hidecker and colleagues to fulfil a role in the classification of communication abilities in daily life in children with cerebral palsy (CP). The CFCS for cerebral palsy aims to enhance communication among professionals and families. The aim of this study is to translate the original -American English - version of the CFCS and to evaluate the psychometric properties the Dutch language version of the CFCS. METHOD and PARTICIPANTS Twenty two children, five in the pilot study and seventeen in the research study, in the age 4 – 10 years, diagnosed with cerebral palsy were included in this study. The parents, a teacher and a speech/physical therapist completed a survey for each child, with questions about their background, child characteristics and questions about the CFCS. Six children also got classified by two unfamiliar persons. For each child, one parent got interviewed with the PEDI-NL, social functioning domain. RESULTS The interrater reliability between two professionals raters was found to be Kappa = 0.69. Between the parent and the speech therapist/physical therapist the kappa was 0.63 and between the parent and teacher kappa was 0.48. The interrater reliability between the unfamiliar professional and the familiar professional rater was found to be Kappa 0.75. The correlation coefficient for the overall score on the domain social functioning and the CFCS-NL is r -.885. The correlation between the receptive items and the CFCS-NL r -.743 and between the expressive items and the CFCS-NL the correlation r is -.831. INTERPRETATION This research indicates that the interrater reliability of Dutch language version of CFCS (CFCS-NL) is good. The results suggest that is important to have certain knowledge about speech and language and communication development in general when using the CFCS-NL. It therefore is recommended that the classification of a child is performed by the parents together with a therapist with certain knowledge about speech and language development. The construct validity of the CFCS-NL, in this study, seems to be good. The CFCS-NL might be useful for both clinical and research applications. The classification system makes it possible to improve communication between parents, professionals and researchers about functional communication on the level of activity and participation. Further research is necessary, especially with regards to the usability in clinical practice. Another point of attention is to extend this study with more participants