A team of Dutch researchers tested the applicability of the CBCL and TRF to 1,041 6- to 18-year-olds attending nonresidential schools for children with ID in the educable range (IQ 60 to 80) or trainable range (IQ 30 to 60; Dekker et al., 2002).
They compared scores and psychometric data for the ID children with scores and psychometric data for a national sample of 1,855 children. Internal consistencies for scale scores were very similar for both groups of children with ID and the children without ID: Cronbach’s alphas ranged from .52 to .90 for children with ID and from .47 to .94 for children without ID. Correlations between CBCL and TRF Total Problems scores for children with and without ID ranged from .30 to .34. The 1-year stability of Total Problems scores was .79 for educable children and .72 for trainable children.
Although the CBCL and TRF were not specifically designed for children with ID, they correlated .83 to .88 with the parent and teacher versions of the Developmental Behavior Checklist, which was designed for children with ID. To identify areas in which children with ID had more behavioral, emotional, or social problems than children without ID, Dekker et al. compared item and scale scores for the different groups. Educable children obtained significantly higher scores on all CBCL and TRF problem scales than children without ID, while trainable children obtained significantly higher scores on all but the CBCL Anxious/Depressed and TRF Somatic Complaints scales.
Dekker et al. also did detailed analyses of all the specific problem items that were reported significantly more often for children with ID than without ID. About 50% of the children with ID were found to have deviant Total Problems scores, compared to 18% of children without ID. The prevalence rate for deviant scores among children with ID was similar to the prevalence rate obtained with different measures in other studies. Dekker et al. concluded that “The advantage of using CBCL and TRF norm scores, which are now available for children with ID as a result of this study, is that it will allow clinicians and researchers to make comparisons to children with similar levels of ID, with non-ID children from the general population, as well as to referred, non-ID children” (p. 1096).
Reference: Dekker, M.C., Koot, H.M., van der Ende, J., & Verhulst, F.C. (2002). Emotional and behavioral problems in children and adolescents with and without intellectual disability. Journal of Child Psychology and Psychiatry, 43, 1087-1098.