Measuring support needs in children with motor disability: Validity and utility of the Supports Intensity Scale (SIS-C)

Abstract

Background: It is unknown whether the Supports Intensity Scale-Children’s version (SIS-C) is valid and useful to assess support needs for children with motor and intellectual disabilities. Aims: (a) To assess the structural validity of the SIS-C using factor analyses in a sample of children with motor disabilities; and (b) to analyze the SIS-C’s reliability and its discriminative capacity in children with different levels of motor function. Methods and Procedures: A cross-sectional design was used to assess 210 children (aged 5–16 years). Among them, 88% had an intellectual disability and 84% had cerebral palsy, with variations in mobility (Gross Motor Function Classification System; level V: 56.19%), handling of objects (Manual Ability Classification System; level V: 38.09%), and communicating (Communication Function Classification System; level V: 42.86%). Outcomes and Results: The model with seven support needs factors and three method factors showed the best fit. The support needs model was reliable and indicated high convergent validity. However, the SIS-C scores showed a strong ceiling effect in children with more significant limitations in gross and fine motor functions. Conclusions and Implications: The seven-dimensional model of support needs could be replicated in children with motor disabilities. However, the usefulness of SIS-C is limited in discriminating between children with greater restrictions in mobility and handling of objects.