Inequalities in child development at school entry: A repeated cross-sectional analysis of the Australian Early Development Census 2009–2018

Background
Australia is the only developed country to consistently undertake a developmental census of its children nationwide. The repeated collection of the Australian Early Development Census (AEDC) has provided an unprecedented opportunity to examine the prevalence of developmental vulnerability across Australia's states and territories, the socio-economic distribution of developmental vulnerability across jurisdictions, and how these distributions might have changed over time.


Methods
This study employed multivariable logistic regressions to estimate the probability of developmental vulnerability within each jurisdiction and AEDC collection year (2009 to 2018), adjusting for jurisdictional differences in socio-demographic characteristics. To explore socio-economic inequalities in child development, adjusted slope index of inequality (SII) models were utilised.


Findings
The results of this study found reductions in the adjusted prevalence of developmental vulnerability over time in Western Australia (26% to 20%) and Queensland (30% to 25%), with an increase observed in the Australian Capital Territory (27% to 30%). Analysis also indicated an increase in socio-economic inequalities over time in the Northern Territory (+12%), the Australian Capital Territory (+6%) and Tasmania (+4%). Sensitivity analysis found these effects to be robust with an alternative measure of socio-economic position.


Interpretation
There is considerable variation in the prevalence and socio-economic inequalities in developmental vulnerability across Australia's jurisdictions. Future research should explore the policy drivers in early childhood education and health contributing to the findings of this study, with a particular focus on jurisdictions where there have been notable changes in developmental vulnerability and socio-economic inequality over time.