Background Care-experienced children are at a greater risk for lower educational attainment. Research suggests that the duration of care is related to educational attainment, as is the type of placement(s) (i.e. foster care, adoption) (Sebba et al. 2015). Given these findings, research is now moving towards understanding the causal mechanisms at play and identifying ‘what works’ from an educational standpoint for looked-after children (Berridge et al. 2020). However, a significant knowledge gap remains regarding i) how placement duration and type(s) contribute towards educational attainment, and, ii) the risk and protective factors for care-experienced children's educational attainment.

Methods Leveraging the Secure Anonymised Information Linkage (SAIL) Databank in Wales, we constructed an electronic cohort of children born between September 2000 and August 2003 (n=611, and 1137) compromised of linked data on social care, demographic information, and educational outcomes. We employed advanced profiling techniques (Nylund-Gibson et al. 2019), to analyse children's first 6 and 10 years in care, using the variables of i) age on entry, ii) type of placement(s) (i.e., foster care, adoption etc.), and iii) duration in care. We used these profiles to predict educational attainment at age 7 and 11, adjusted for key sociodemographic factors (i.e., gender, deprivation). Lastly, we utilised mediation analysis (McLarnon and O’Neill, 2018) to identify which individual (i.e., mental health) or school factors (i.e., behaviour) could explain the relationship between each care profile and educational attainment.

Results Seven profiles best fitted both models. For the first six years of life, those who experienced foster care which progressed to adoption had the highest attainment (~1.00 masked), whereas those who entered foster care on their 4^th birthday had the lowest attainment intercept (0.40, 0.13 – 0.68). For the 10-year profile, the foster care progressing to adoption group had the highest attainment (0.60, 0.34 – 0.86), whereas the short-term, late foster care group had the lowest attainment (0.36, 0.15 – 0.58). We found that sex, ethnicity, and birthweight contributed to education attainment when adjusted for the profiles.

Conclusion We find that children who are fostered and adopted early have the greatest chance at meeting the expected levels for educational attainment at age 7 and 11 years, whereas children who spent most of their time in foster care are the least likely, regardless of duration or age on entry. Policymakers and those working in related sectors should consider these results in relation to school policy and practice to support care-experienced young people reach their potential.