The association between the Ages and Stages Questionnaire 3 assessment at age 2 and the Early Years Foundation Stage at age 5: A longitudinal observational study using routine data

IntroductionImproving the number of children who achieve a good level of development (GLD) on the Early Years Foundation Stage Profile (EYFSP) at the end of their first school year (aged five), and reducing the equity gap in this outcome was made a national priority in England in 2025. Children in England also receive a developmental assessment - the Ages and Stages Questionnaire-3 (ASQ-3) aged two. No study to date has explored the association between the ASQ-3 and EYFSP assessments. The aim of this study is to explore whether a GLD on the ASQ-3 is predictive of a GLD on the EYFSP using a longitudinal sample of children. MethodsLongitudinal pseudonymised data from the Connected Bradford dataset was used to undertake multiple regression analyses. ResultsFrom September 2013 to May 2025, 47,046 children had an ASQ-3 record, of whom 6,021 (13%) had a linked EYFSP record. Boys and children living in the lowest quintiles of the Index of Multiple Deprivation were less likely to achieve a GLD on both the ASQ-3 and the EYFSP. Children from South Asian ethnic groups were least likely to achieve a GLD on the ASQ-3, whilst White Other children were least likely to achieve a GLD on the EYFSP. Achieving a GLD on the ASQ-3 was predictive of a GLD on the EYFSP, with children who achieved a GLD on the ASQ-3 having more than three-times the odds of achieving a GLD on the EYFSP (OR 3.18, 95% CI 2.70 to 3.75). ConclusionThis study highlights the potential value of using the ASQ-3 results to intervene early and support more children to become school ready. These findings also show that many children have fallen behind by the age of two, thus emphasising the importance of intervening from the earliest possible moment to reduce inequities in child development. Key MessagesO_ST_ABSWhat is already known on this topicC_ST_ABSO_LIIn England, approximately 3 in 10 children do not reach a Good Level of Development (GLD) on the Early Years Foundation Stage Profile (EYFSP) which is undertaken at the end of the Reception year of school. Reaching a GLD is associated with later educational attainment. C_LI What this study addsO_LIThis study is the first to use longitudinal data to explore whether achieving a GLD on the developmental assessment undertaken at age 2 - the Ages and Stages Questionnaire 3 (ASQ-3), can predict the GLD on the EYFSP at school. C_LIO_LIThis study found that children who did not achieve a GLD on the ASQ-3 had three times the odds of not achieving a GLD on the EYFSP. Boys, those living in areas of high deprivation, and those from White Other backgrounds were also less likely. C_LI How this study might affect research, practice or policyO_LIThis study highlights the potential value of using the ASQ-3 results to intervene early and support more children to become school ready. These findings also show that many children have fallen behind by the age of two, thus emphasising the importance of intervening from the earliest possible moment to reduce inequities in child development. C_LI