Comparing reliability and validity of pediatric instruments for measuring health and well-being of children with spastic cerebral palsy

This study sought to examine the reliability and validity of three generic instruments for measuring the health of children with cerebral palsy (CP) and to compare them with a disease-specific measure, the Gross Motor Function Measure (GMFM). The Pediatric Evaluation and Disability Inventory (PEDI), the Pediatric Outcomes Data Collection Instrument (PODCI), and the Child Health Questionnaire (CHQ) were completed by the primary caregivers of 115 young children with spastic CP. The GMFM was administered to the children. The mean age of the sample was 5 years 8 months (range 3:1 to 10:4) and consisted of more males (58%) than females. The PEDI scales demonstrated higher internal consistency than the PODCI and CHQ scales. In comparison with the GMFM, the PODCI transfer and mobility scale (relative validity, 62%) and the PEDI mobility scale (relative validity, 53%) detected the most significant health differences between children with hemiplegia, diplegia, and quadriplegia. The PEDI social function scale detected the largest differences in cognitive function between children with an IQ of less than 70 compared with those with an IQ of 70 or greater. The reliability and validity of these different instruments varied significantly in this patient population.