Longitudinal effects of a language intervention in language and reading skills in Chilean DLD preschoolers

The current study evaluates the effect of a hybrid-training program (phonological awareness and vocabulary) on concurrent language skills and the subsequent reading abilities of a group of preschoolers with developmental language disorder (DLD). Forty-one children with DLD ( M _age  = 65 months) were recruited from 10 schools in Santiago, Chile. Classrooms were randomly assigned to an intervention or control group. The intervention group received an intensive training combining phonological awareness and vocabulary, whereas the control group continued with the usual activities developed at school. Children were tested at three time points: prior to intervention (beginning of kindergarten), after the intervention (end of kindergarten), and one year after the intervention concluded (end of year one). At all times, phonological awareness and vocabulary were measured. Additionally, in the final testing point, reading comprehension and decoding were also evaluated. Results showed that children in the intervention group outperformed children in the control group in syllabic awareness only, at the end of the intervention and sustaining the improvement one year later. Conversely, reading comprehension and decoding were not affected by the intervention in oral language skills. These findings are discussed considering the challenges of supporting DLD children's language and reading through interventions based on oral language skills, considered key predictors of reading.