Sensitivity of the BASC-2 Adaptive Skills Composite in detecting adaptive impairment in a clinically referred sample of children and adolescents.

The Behavior Assessment Scale for Children (BASC-2) is widely used to assess for internalizing/externalizing behavior problems; however, the role of its adaptive scales is not well established. This study examined the sensitivity of the parent version of the BASC-2 Adaptive Skills Composite (ASC) in identifying children with impairments on a more comprehensive measure of adaptive functioning, the Adaptive Behavior Assessment System (ABAS-II). Participants were referred for neuropsychological assessment (N = 1884, M age = 10.96 years, SD = 3.50, 65% male). The ASC, rather than individual BASC-2 adaptive scales, showed the strongest correlations with the ABAS-II General Adaptive Composite (GAC) and domains. Receiver operating characteristic analysis showed that the BASC-2 ASC discriminated children with impaired adaptive functioning on the ABAS-II (≥ -2 SD) from those without impairment (area under curve range = .86[social domain] to .78[practical domain]); however, sensitivity was inadequate at the typical -2 SD cut-off (48%). A -1 SD cut-off on the BASC-2 (T-score ≤ 40) was more appropriate for predicting impairment on the ABAS-II (89%). Among children with impaired IQ, the ABAS-II GAC was impaired in 69% compared to only 36% on the ASC. Findings have implications for the diagnosis of Intellectual Disability and for quantifying the functional impact of other diagnoses, particularly with the release of DSM-5.