Assessing support needs in children with intellectual disability and motor impairments: measurement invariance and group differences

Background This study assessed the equivalence of the measurement of support needs between children with intellectual disability (ID) and children with intellectual and motor disabilities (IMD) and compared both groups in the different domains of support. Method The Supports Intensity Scale-Children's Version was used to assess the support needs of 713 children with ID and 286 children with IMD, mainly associated with cerebral palsy. Results The results supported measurement invariance between the group of ID and IMD, which allowed to conduct comparison between them. Children with IMD scored higher on support needs than did children without IMD, suggesting that children with IMD needed more support than their peers without motor impairments. Furthermore, the ID levels interacted with motor impairments: at the highest levels of ID, groups tended to be similar in support needs, with high scores and low variability. The greatest differences were found in the domains of Home and Community activities. Conclusions This study points to the across-condition of the construct of support needs in populations with intellectual and developmental disabilities. However, additional mobility impairments should be considered during the evaluation and planning of systems of support. In this regard, the Supports Intensity Scale-Children's Version might have limitations when discriminating between samples with high support needs.