Predicting expressive vocabulary change in young children growing up in Ireland

Abstract

During the preschool years expressive vocabulary development is highly variable, which makes it difficult for healthcare and education professionals to identify children with delays that require early intervention services. Previous research has highlighted the need to identify a reliable set of risk and protective factors which predict expressive vocabulary outcomes. The current study explored patterns of expressive vocabulary development between 3 and 5 years using a large population-based sample of 8,266 children. Expressive vocabulary was measured using the naming vocabulary subtest of the British Abilities Scales (BAS) and information relating to additional risk factors was gathered through questionnaires with the primary caregiver. Four patterns of expressive vocabulary development were identified, 89.9% of children had no expressive vocabulary delay, 2.8% of children were delayed at 3 years only (resolving delay), 5.0% were delayed at 5 years only (late onset delay) and 2.3% had a persisting expressive vocabulary delay. Five factors differentiated between the no delay and late onset delay groups. These factors were, learning English as an additional language, low parent education levels, low frequency of book reading, low frequency of home learning activities and few children’s books in the home. Learning English as an additional language was the only factor which differentiated between resolving delay group and children with a persisting delay. The information gleaned from the current study has implications for clinical practice and identifies the need for a service delivery model which incorporates monitoring over time and providing intervention on the basis of language abilities and associated risks.