Aim: Pacific children fare poorly on health and educational outcomes, including literacy. Early interventions are considered critical in reducing educational disparities. A prediction model was constructed to analyse the factors associated with Pacific children's English receptive vocabulary, an important component of English language development. Methods: A birth cohort study of Pacific children was used to construct a classification tree model and predict the proportions of Pacific children who performed strongly in a standardised test of English receptive vocabulary at 6 years of age (n = 1019). Classification trees were constructed using 10-fold cross-validation (CV) and pruned using the one-standard-error rule. Prediction errors were directly estimated using leaveone-out CV. Results: Analyses of misclassification errors from the pruned model gave false negative and positive rates of 19 and 19% from re-substitution and 54 and 21% from leave-one-out CV estimation, respectively. Of the predictors, maternal acculturation, small birthweight and performance in early developmental screening test at 4 years of age were found to have the highest goodness of split. Conclusions: The cultural environment to which Pacific children were exposed in early childhood, indicated by the maternal acculturation, was more crucial in distinguishing children with strong English-receptive vocabulary skills than socio-economic or prenatal conditions. This highlights the importance of integrating the cultural environment into designing measures for facilitating Pacific children's language development.What is already known on this topic 1 Educational and health outcomes are bi-directional and positively associated. 2 There are persistent disparities in children's educational and health outcomes in most developed countries, and Pacific children are among those worst affected in New Zealand. 3 Pacific children's early language and literacy skills, assessed using conventional literacy school measures, were found to be lower on average than the overall student population, highlighting the need for early interventions.
What this paper adds1 Cultural environment was incorporated into a prediction model for Pacific children's English-receptive vocabulary at 6 years of age, and the results emphasise the importance of maternal cultural orientation in distinguishing children with strong Englishreceptive vocabulary skills from those who scored below the age-appropriate range. 2 This suggests the need for cultural considerations when attempting to study Pacific children's language outcomes and when designing and implementing strategies for reducing disparities. 3 Classification trees were constructed, and their performances were analysed, indicating their potential utility and limitations in predicting educational outcomes.Educational and health outcomes are considered inextricably linked and bi-directional. 1 In fact, enhancing equity in educational attainment is seen as one of the most important ways to tackle disparities in health outcomes. 2 Mo...