Early joint attention abilities measured by the ADOS-2 predict subsequent expressive language development in minimally verbal autistic children.

Background: Most preschool autistic children exhibit substantial language delays, yet only ∼25% remain minimally verbal (MV) throughout life. Developing expressive language is crucial for improving outcomes. This study examined early predictors of later expressive language growth in MV preschool autistic children. Methods: Data from 99 MV autistic children (mean age 27.7 months at diagnosis) who completed ADOS-2 assessments at diagnosis and 12-24 months later were analyzed. Children were stratified into three groups according to their language abilities at follow-up (MV, one-word, and phrases). Logistic regression was used to determine whether baseline ADOS-2 calibrated severity scores (CSS), non-verbal cognitive abilities, or Joint Attention (JA), derived from six ADOS-2 items, enabled prediction of expressive language abilities at follow-up. Results: Children who successfully developed expressive language (one-word/phrases) had significantly lower baseline ADOS-2 social affect CSS and JA scores, but did not differ in their non-verbal cognitive abilities or ADOS-2 restricted and repetitive behaviors CSS. Gains in JA were significantly larger in children who developed expressive language. Conclusion: MV preschoolers with better social abilities at diagnosis, specifically JA, were more likely to develop expressive language within 1-2 years. Joint attention scores derived from the ADOS-2 offer an easily accessible and widely available measure with important prognostic value for MV children.