Does baseline language ability predict response to early intervention for toddlers with early signs of autism? Evidence from a caregiver-mediated program

Jessica Ann Brian^1*Ian Roth¹Lonnie Zwaigenbaum²Isabel Smith³Lori-Ann Rosalind Sacrey²Kate Bernardi¹Stacey MacWilliam⁴Sara Daoud¹Erin Dowds¹Sanne Jilderda²Samara Osten¹Anna Michelis¹Abbie Solish¹

• ¹Holland Bloorview Kids Rehabilitation Hospital, Toronto, Canada
• ²University of Alberta, Edmonton, Canada
• ³Dalhousie University, Halifax, Canada
• ⁴IWK Health Centre, Halifax, Canada

Background. Caregiver-mediated interventions (CMIs) for young autistic children are supported by mounting evidence of efficacy. Attempts to identify child-level factors that predict treatment response have yielded inconsistent findings, with very few such studies focused on the toddler age range. Objective. Secondary analysis of data from a randomized control trial (NCT03215394) was conducted to explore predictive relationships between toddlers’ communication-related abilities and response to treatment in a CMI program. Participants. 67 toddler-caregiver dyads (62 mothers, 4 fathers, 1 grandmother) participated across three Canadian sites. Participating toddlers (52 boys, 15 girls) had a diagnosis of autism or early signs thereof and ranged in age from 18 to 32 months (M = 25.95 months). Methods. All dyads participated in a 12-week CMI (the Social ABCs). Communication-related skills were assessed at baseline using a direct standardized assessment of expressive language, a caregiver interview to capture receptive and expressive communication, and a parent-report inventory to document words used and understood. Analyses. A series of regressions with simple mediation analyses were performed to identify communication-related predictors of intervention change scores for caregiver fidelity and toddler outcomes. In all cases, toddler age was entered as a mediator to explore any influence on these relationships. Results. Toddlers’ functional communication inversely predicted their caregivers’ mastery of program strategies. Specifically, lower toddler functional receptive and expressive communication predicted larger gains in caregivers’ strategy use. Conversely, higher baseline (receptive but not expressive) communication-related skills predicted greater gains in toddlers’ responsivity. Trends emerged for prediction of toddler smiling and social orienting. The clinical measure selected for this study did not predict outcomes. Conclusions. Caregiver-reported information about toddler communication-related skills was informative for predicting the primary program outcomes. Findings may be helpful in informing clinical triage decisions and personalizing intervention approaches.