Background and purpose: Cerebral palsy is a common disorder in children leading to their dysfunction in many aspects. Therefore, to provide appropriate treatment plan that could improve the function of these children, a valid assessment tool is needed. Pediatric Evaluation Disability Inventory (PEDI) is designed to evaluate the performance of children with disabilities in three dimensions: self-care, mobility, and social function. The purpose of this study was to evaluate the reliability of the Persian version of PEDI in children with cerebral palsy aged 3 to 9 years old.

Materials and methods: In this study, 75 participants were selected by convenience sampling. Information was collected using demographic questionnaire and Gross Motor Function Classification System (GMFCS). The parents were interviewed and PEDI was completed. After two weeks, in order to evaluate the reliability of the test-retest, 22 parents were re-interviewed. Internal consistency was examined by Cronbach's alpha, and the reliability of the test-retest was assessed by intra-class correlation coefficient (ICC).

Results: In examining the internal consistency, Cronbach's alpha was found to be high (0.94-0.98).The results of test-retest reliability of the functional skills and caregiver assistance scale were excellent (0.96-0.97). Also, the results of test-retest reliability in modification scale were excellent in self-care and social performance (0.99 and 1, respectively) and good in mobility dimension (0.66).

Conclusion: This study proved the internal consistency and test-retest reliability of the Persian version of PEDI in evaluating the performance of Persian-speaking children with cerebral palsy. Therefore, PEDI could be applied in research and clinical settings for evaluation of children with cerebral palsy in Iran.