Inconsistencies with physical functioning and the child health questionnaire in children with cerebral palsy

To explore the performance of the Physical Functioning (PF) subscale of the Child Health Questionnaire (CHQ) in children with cerebral palsy (CP).

Parents of 177 children and adolescents (age 3 to 18 years) with CP completed the CHQ -Parent Form 50. Severity of CP was assessed using the 5-level Gross Motor Function Classification System (GMFCS), in which higher levels reflect more severe impairment.

PF scores were negatively correlated with GMFCS classification (R = -0.62) and were distributed bimodally in subjects with severe motor impairment. For GMFCS classifications IV and V (n = 59), PF scores were very low (means, 9 to 28; medians, 0 to 8); however, 12% of these subjects had excellent PF scores (> 88) despite being nonambulatory.

Although the CHQ PF subscale correlated well with the GMFCS, the CHQ questions on physical functioning resulted in unexpected responses in approximately 1 in 8 subjects with severe CP. These unanticipated responses to the PF subscale questions may be due to ambiguity in the questions (which do not differentiate between health problems and disability) or to alternative parental interpretation of physical functioning. Confusion in differentiating health status and functional status may make the CHQ less useful in children with significant disabilities.