Abstract
BACKGROUND: Parent-report measures are increasingly used in research and clinical settings to assess early cognitive outcomes after preterm birth. Directly observed cognitive measures often share a correlational structure, from which a general factor of cognition is calculable. We investigated associations between gestational age at birth and language, attention and executive function at two years using parent-report measures and examined whether a general factor could be derived from parental assessment of abilities across these domains. METHODS: 183 2-year-old children (96 preterm and 87 term) were assessed for language using the Vineland Adaptive Behaviour Scales-3rd edition and the MacArthur-Bates Communicative Development Inventory, attention using the Early Childhood Behaviour Questionnaire, and executive functions using the Behaviour Rating Inventory of Executive Function-Preschool version. Linear regression was performed to determine associations with gestational age for each domain, adjusting for infant sex, age at testing, and maternal education. Spearman correlations ( rho) and principal component analysis were used to investigate correlational structure across domains. RESULTS: By parental report, gestational age at birth predicts language (standardised estimates 0.13 to 0.21, corrected p-values <0.05), but not attention or executive functions, at age 2 years. Scores across domains were modestly correlated: language and attention ( rho = 0.29 to 0.32; p- values <0.05), attention and executive functions ( rho = 0.19 to 0.30; p- values <0.05), language and executive functions ( rho = 0.19; p- values <0.05). The first principal component explained a substantial proportion of variance (35.4%) amongst measures, indicating a general factor. CONCLUSIONS: Parents of 2-year-old preterm children report reduced language ability, but similar attention and executive function development compared to term-born children. A general factor explains a significant proportion of variance in parental ratings of cognition across domains in early childhood.