An Item Analysis of the Instability of Parent Report Scores on the Pediatric Evaluation of Disability Inventory

Abstract

Purpose: To evaluate item instability of the Pediatric Evaluation of Disability Inventory – Functional Skills Scale completed by parents. Methods: Scoring instability was analyzed between baseline and after 6 months of intervention (T1-T2) on 113 children and between end of intervention and 3 months afterwards (T2-T3) on 101 children. Results: Scoring instability was present among children between T1-T2 (19% of children > 5 unstable items) and between T2-T3 (34% of children > 5 unstable items). Ten or more children had unstable scores between both time periods for 21 out of 132 (16%) items. More instability was found between T2-T3, among older children in T1-T2, and among children with less motor limitations in T2-T3. Conclusions: Item instability was present, but the magnitude was low. Suggestions for parental scoring on the PEDI-FSS include clarifying the scoring reference, the subjective words, the guidelines for multi-faceted items, and the impact of the outdoor environment.