The Early Language in Victoria Study (ELVS): A prospective, longitudinal study of communication skills and expressive vocabulary development at 8, 12 and 24 months

The aim of this paper is to provide an overview of the methods and preliminary findings from the Early Language In Victoria Study (ELVS) a prospective, longitudinal study of child language impairment. Specifically, we provide a summary of early communication and vocabulary development and examine the contributions a range of risk factors and predictors make to these outcomes. The sample was a community-ascertained cohort of 1911 infants, recruited at 8 months and followed at ages 12 and 24 months. The main outcomes of interest were parent reported infant and toddler communication (Communication and Symbolic Behavior Scales, CSBS) and expressive vocabulary (MacArthur-Bates Communicative Development Inventories, CDI). Predictors included gender, preterm birth, birth weight, multiple birth, birth order, socioeconomic status, maternal mental health, maternal vocabulary and education, maternal age at birth of child, non-English-speaking background, and a family history of speech and/or language difficulties. Results demonstrated rapid development in communication skills measured by the three CSBS domains (social, speech and symbolic) and in vocabulary development (CDI). There was rapid growth in gesture use between 8 and 12 months and symbolic use of objects between 12 to 24 months. At approximately 24 months, 19.7% had delayed expressive vocabulary. Male gender and family history were associated with poorer outcomes on the CSBS and the CDI at 8, 12 and 24 months, although the regression models explained only a small amount of the variance in outcome. In summary we measured rapid growth in communication skills and vocabulary between 12 and 24 months, but the hypothesized early risk factors and predictors explained little of the variation in these outcomes. We conclude that the risk factors/predictors examined in this study therefore seem unlikely to be helpful in screening for early language delay.