Pediatric physical functioning reference curves

We developed normative profiles of physical functioning (mobility and self-care) in infancy up through 14 years of age with an expanded version of the Pediatric Evaluation of Disability Inventory. Mobility and self-care reference curves were based on the original Pediatric Evaluation of Disability Inventory standardization data (n = 412) and data from an additional cross-sectional, convenience sample (n = 373) via web-based survey, telephone or in-person interviews of parents. This new sample, which included children up through 14 years-of-age, was stratified for race, age, and sex, but was primarily limited geographically to the Northeast region of the United States. Goodness of fit of male, female, and combined sex (male and female) reference curves was examined. The mobility and self-care reference curves produced efficient and well-fitting estimates of conventional percentiles (3rd, 10th, 25th, 50th, 75th, 97th). Differences between males' and females' reference curves were negligible. This study highlights the use of these reference curves for determining the functional impact of Pompe disease, a lysosomal storage disorder that affects skeletal and cardiac muscle, restricting normal expression of mobility and self-care activities. This physical functioning instrument could also be used to evaluate the impact of muscle weakness in other neuromuscular disorders.