Reliability and Validity of the Pediatric Evaluation of Disability Inventory

The reliability and validity of the Pediatric Evaluation of Disability Inventory (PEDI) were investigated in a series of three studies: 1) intrarater reliability (n = 23), 2) interrespondent reliability (n = 1 7), and 3) concurrent validity with the Peabody Developmental Motor Scales (PDMS) (n = 25). In the intrarater reliability component of the study, parents were interviewed using the PEDI two times, with one week between interviews. Intraclass correlation coefficients (ICC) (3,1) were high for the summary scores for each domain and moderate to good for the content areas within each domain. Interrespondent reliability was investigated using parents and therapists as respondents. ICC (2,1) ranged from 0.18 to 0.94 for content areas within the domains, indicating varying degrees of reliability on the items. Those items that had inconsistent ratings between parents and therapists were ones typically not observed in the clinic setting. The results suggest that reliability is increased when the PEDI is administered to both the parent and the primary therapist, as their perceptions of the child differ on some of the PEDI items. Pearson correlation coefficients between subscale scores for the PDMS and the summary scores from each domain of the PEDI were moderate to high (r = 0.64–0.95), indicating that these tests measure similar aspects of the child's performance. The PDMS was more sensitive in identifying children as delayed, when using the criterion of 1.5 SD below the mean. In general, the findings support the PEDI as a reliable and valid assessment of functional performance in children with disabilities. (Pediatr Phys Ther 1996;8:15–24)