Purpose: Early interventions for children at risk for developmental language disorder (DLD) have not systematically targeted the transition from vocabulary to syntax. This randomized controlled trial examined short-term effects of the Enhanced Milieu Teaching–Sentence Focused (EMT-SF) intervention, an 18-month multiphase intervention, on vocabulary after 6 months (child age = 36 months) and grammar after 12 months (child age = 42 months). Method: Participants included 108 children at risk for DLD between 30 and 31 months of age and their caregivers. Participants spoke only English in the home and were primarily from White, non-Hispanic, college-educated families. Children were randomly assigned to the treatment or control group. Interventionists coached caregivers on EMT-SF strategies via telehealth. Following 6 months of intervention, a latent variable composed of Peabody Picture Vocabulary Test–Fifth Edition (PPVT-5) and Expressive Vocabulary Test–Third Edition scores characterized vocabulary outcomes. Following 12 months of intervention, a latent variable composed of scores on the Structured Photographic Expressive Language Test–Preschool 2 and the Test of Early Grammatical Impairment characterized grammar outcomes. Results: At 36 months, mean vocabulary scores for both groups fell within the average range. Structural equation modeling (SEM) revealed no significant short-term treatment effect on the vocabulary latent variable ( p = .458); however, post hoc analyses indicated a significant effect on PPVT-5 scores ( p = .042). At 42 months, mean grammar scores for both groups fell below the average range. SEM revealed a significant short-term treatment effect on the grammar latent variable ( p = .047). Conclusions: The EMT-SF treatment group demonstrated significantly higher single-word receptive vocabulary scores at 36 months and grammar scores at 42 months than the control group. Grammatical difficulties persisted for most children in both groups at 42 months, further documenting that grammar is a particularly vulnerable language domain for children at risk for DLD. Supplemental Material: https://doi.org/10.23641/asha.32581677
Hadley et al. (Thu,) studied this question.