Cross-cultural validity of the German version of the Pediatric Evaluation of Disability Inventory (PEDI-G)-a Rasch model application.

Abstract

The aim of this study was to evaluate the cross-cultural validity of the German version of the Pediatric Evaluation of Disability Inventory (PEDI-G) when used in Austria, Germany and Switzerland. A total of 118 girls and 144 boys participated in this study; 198 of the children (75.6%) had a developmental disability and 64 (24.4%) were without a known disability. The mean age was four years (range 11 months to 10 years and six months, SD 1.91). Item goodness of fit, differential item functioning (DIF) and differential test functioning (DTF) were evaluated by use of a Rasch model. Twenty-four (11.6%) out of 206 items of the Functional Skills Scale and one (5%) out of 20 items of the Caregiver Assistance Scale demonstrated misfit according to the Rasch model. Thirty-four (16.5%) out of 206 items of the Functional Skills Scale and no item from the Caregiver Assistance Scale demonstrated DIF. Almost half (46%) of the items demonstrating misfit also demonstrated DIF, indicating an association between them. The DIF by country only demonstrated a minimal impact on the person measures of the PEDI-G. Even though some items did not meet the statistical and clinical criteria set, the PEDI-G can be used, on a preliminary basis as a valid tool to measure activities of daily living of children with and without a disability in these countries. Further larger studies are needed to evaluate more psychometric item properties of the PEDI-G in relation to context.