This review examined how different definitions of language impairment affect clinical classification in speaking autistic adolescents and young adults. The study looked at 75 participants and compared various criteria ranging from -1 SD to -1.5 SD cutoffs against standard language measures.
Researchers found that using stricter definitions resulted in a greater proportion of participants being classified as having language impairment. Additionally, these stricter cutoffs led to greater overall consistency in clinical classification across individual language measures. However, there was no simple one-to-one ratio between the strictness of the cutoff and the resulting classification.
The analysis also revealed three distinct profiles based on language and nonverbal cognitive skills, though each group was quite heterogeneous. Individual performance varied significantly across different language measures. The study highlights a lack of consensus on how to operationally define language impairment in this age group.
Readers should understand that these findings support using multi-domain approaches to characterize language skills. It is important not to infer causation from these associations or to overstate the distinctness of the identified clusters without further evidence.