Meaningful Determinants of Early Response: Predicting and Characterizing Behavioral Changes for Minimally Verbal Autistic Children

Autism encompasses a wide range of developmental abilities. Notably, nearly 30% of children fail to achieve phrase speech by kindergarten, even when provided with years of early interventions or participation in rigorously conducted clinical trials. Our understanding of why these challenges persist is limited by an underrepresentation of minimally verbal (MV) children in autism research. Consequently, our understanding of benefits from early intervention is limited. There is promising evidence that minimally verbal autistic children may benefit from an adaptive approach that can address their dynamic needs. Adaptive interventions give service providers the ability to adjust strategies and approaches to match the needs of an individual. A critical component of an adaptive intervention approach is the ability to assess response to the intervention in order to make a decision on the best course of action. Previous work in identifying response to intervention has identified key predictors such as IQ, age, and expressive language ability. However, it may be helpful to examine core developmental skills as important variables driving decisions in adaptive intervention approaches. The current study aims to explore how core developmental skills of MV autistic children are related to early response in the first phase of an adaptive intervention. Our secondary aim examines the skills that are changing among MV children identified as fast responders. This is a secondary data analysis of 194 MV autistic children (M = 72.42 months old, SD = 15.14 months) that were recruited to receive an adaptive intervention. The children were assessed for their development in social communication, play, expressive language, and cognition prior to receiving the adaptive intervention, and again after 6 weeks of intervention. At the 6-week mark, children were also assessed for their response to the intervention using a Clinical Global Impression Scale (CGI), which identified children as fast or slow responders to the intervention. Logistic regressions examined the association between core developmental skills and early response to initial intervention while controlling for site differences, age, and gender. Child-initiated joint attention (Z = 2.15, p = 0.031) predicted fast response to intervention. Higher play mastery level and more play diversity at baseline also significantly predicted fast response (Z = 2.20, p = 0.03; Z = 2.01, p = 0.04). Examination of developmental skills that changed during the initial intervention phase showed requesting skills and responding to joint attention as important determinants. Children with improved requesting skills (Z = 2.69, p = 0.007) and response to joint attention (Z = 2.69, p = 0.007) had increased odds of being identified as fast responders to the intervention. Identifying important core developmental skills among MV autistic children can play a critical role in the decision-making process of adaptive interventions. Especially helpful for MV children is the ability to identify meaningful skills and changes related to early intervention. Our analyses identified the importance of core developmental skills like joint attention and play as meaningful predictors of fast responders. Furthermore, the skills that made the most change among these fast responders were requesting skills and response to joint attention.