Psychometric evaluation and distribution of classification systems in children with cerebral palsy in Japan

The study sought to examine the content validity, the intra- and inter-rater reliability, and concurrent validity of the Japanese versions of the Manual Ability Classification System, the Communication Function Classification System, and the Eating and Drinking Ability Classification System, and representation of the distribution of the levels of each classification systems in comparison to the Gross Motor Function Classification System levels for children with cerebral palsy.

The Japanese versions were developed using the back-translation method. For content validity, professionals were asked to complete a questionnaire including items on the appropriateness of the translation, its validity, and distinctions among levels. For reliability, professionals used the three classification systems twice in children with cerebral palsy. For concurrent validity, relationships among the four classification systems were examined by correlation analyses.

Participants included twenty-one professionals and 290 children with cerebral palsy (mean age: 12 years two months, female: 132, male: 158). The content validity was generally good. For reliability, the lower limit of the 95% confidence interval for the intraclass correlation coefficients was greater than 0.89, and the correlation coefficients were high.

The results of this study showed good reliability and validity of the functional classification systems in Japan.