Commentary on “Validation of the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND)”

Abstract

“How should I apply this information?” The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) provides a standardized method of examining the movement ability of infants with severe muscle weakness, who cannot tolerate motor developmental or functional assessments. Developed for use with infants with spinal muscular atrophy (SMA), whose primary impairment of muscle weakness limits functional movement, the CHOP INTEND examines functional muscle strength using a uniform scoring scale (0–4). The CHOP INTEND can be done in a short period of time and does not place infants in positions that are poorly tolerated. This instrument allows one to examine strength during reflexive, spontaneous, or goal-directed movement, while also examining the behavioral state of infants. Previous studies have found the instrument to be reliable and valid for use with infants and young children (mean age approximately 3 years). In further examining validity of the CHOP INTEND, the current study demonstrates that the instrument can differentiate children by severity of the disorder and need for respiratory support. It also correlates with age and progression of the disease. “What should I be mindful about in applying the information?” The CHOP INTEND is most appropriate for infants with severe weakness (ie, SMA) and would not be an appropriate instrument to measure activity or participation for children with mild to moderate weakness or hypotonia. The current validation study of the CHOP INTEND is limited by a small sample size, covering a very large age range (3 months to 21 years). Although the instrument may have the potential to document muscle strength in children and young adults with severe weakness, the items might not be the most valid for the older population. Because of the terminal nature of SMA-1, only a limited number of survivors at older ages are included, leading to an age-biased sample. Although the findings of this study may support the CHOP INTEND as an outcome measure for intervention studies, additional research is necessary with larger, more homogeneous samples. Longitudinal studies would also be useful to chart the progression of SMA and other similar diseases using this instrument. Donna Cech, PT, DHS Midwestern University, Downer's Grove, Illinois Nancy L. Biedry, PT, MS Central DuPage Hospital, Winfield, Illinois