ABSTRACT
PURPOSE: Diagnostic accuracy of autism spectrum disorder (ASD) is crucial to track and characterize ASD, as well as to guide appropriate interventions at the individual level. However, under-diagnosis, over-diagnosis, and misdiagnosis of ASD are still prevalent. METHODS: We describe 232 children (MAge = 10.71 years; 19% female) with community-based diagnoses of ASD referred for research participation. Extensive assessment procedures were employed to confirm ASD diagnosis before study inclusion. The sample was subsequently divided into two groups with either confirmed ASD diagnoses (ASD+) or unconfirmed/inaccurate diagnoses (ASD-). Clinical characteristics differentiating the groups were further analyzed. RESULTS: 47% of children with community-based ASD diagnoses did not meet ASD criteria by expert consensus. ASD + and ASD- groups did not differ in age, gender, ethnicity, or racial make-up. The ASD + group was more likely to have a history of early language delays compared to the ASD- group; however, no group differences in current functional language use were reported by caregivers. The ASD + group scored significantly higher on ADI-R scores and on the ADOS-2 algorithm composite scores and calibrated severity scores (CSSs). The ASD- group attained higher estimated IQ scores and higher rates of psychiatric disorders, including anxiety disorder, disruptive behavior, and mood disorder diagnoses. Broadly, caregiver questionnaires (SRS-2, CCC-2) did not differentiate groups. CONCLUSION: Increased reported psychiatric disorders in the ASD- group suggests psychiatric complexity may contribute to community misdiagnosis and possible overdiagnosis of ASD. Clinician-mediated tools (ADI-R, ADOS-2) differentiated ASD + versus ASD- groups, whereas caregiver-reported questionnaires did not.
ABSTRACT
Purpose: Assessment of pragmatic language difficulties is limited with conventional tests but can be performed with informant reports. We evaluated the performance of a parent-completed language scale in differentiating autism from typical development (TD) and another neurodevelopmental disorder. Specifically, we aimed to gauge the respective values of structural and pragmatic language scores for diagnostic discrimination and for predicting severity of social impairment in autistic children. Method: 174 children aged 7 to 17 (101 with autism, 45 with ADHD, 28 with TD) were evaluated with the ADOS-2 and an abbreviated version of the WISC. Parents completed the Children's Communication Checklist, 2nd Edition (CCC-2) and the Social Responsiveness Scale. CCC-2 mean differences across diagnostic groups were tested with analysis of variance and covariance. Multiple linear regression was used to compare the structural and pragmatic CCC-2 scores in predicting autism symptom severity. Results: Both structural and pragmatic language scores discriminated between the three diagnostic groups, with stronger effects for the pragmatic scores. Pragmatic scores remained robust predictors of ADHD and ASD diagnoses even after accounting for cognitive and structural linguistic differences. Among autistic children, social impairment severity was associated with pragmatic, but not structural, language profiles. Conclusions: In order to characterize pragmatic language, easy to administer parent questionnaires such as the CCC-2 may support clinicians who are considering an autism diagnosis and needing to evaluate and monitor social communication.
