Stability of parent report on Mobility and Self-Care item scores of the Pediatric Evaluation of Disability Inventory.

Secondary analysis using data from a clinical trial was performed to evaluate the stability of individual items of the Mobility and Self-Care functional skills scales of the Pediatric Evaluation of Disability Inventory (PEDI). Parents of 113 children aged 1-6 years old with cerebral palsy completed the PEDI twice by questionnaire 6 months apart. An item was classified "unstable" if the score changed from capable to unable. The number of children with more than five unstable items and the number of items with more than five children having unstable scoring patterns were calculated. Nineteen children (17%) and 13 items had unstable scoring patterns. The majority of PEDI items demonstrated stability of parent scoring. Examination of unstable items suggests that parents may need assistance in understanding the difference between "usual" and "best" performance, interpreting descriptors such as "thoroughly," and maintaining the same context reference for outdoor mobility items.