Interventions for pre‐school children in foster care: A systematic review of the foster carer and system level outcomes from randomised controlled trials

Abstract Background Children in foster care are at increased risk of experiencing cognitive, emotional and behavioural difficulties. There is a window of opportunity for early intervention associated with developmental sensitivity in the early years. Foster carers and the systems supporting them play a central role in intervention and support for the young person. This systematic review explores the effectiveness of interventions for pre‐school children in foster care, in improving carer sensitivity, stress and placement stability. Methods Embase, Medline, CINAHL, PsycInfo and Cochrane Library were search systematically for relevant articles, including randomised controlled trials (RCTs) available by 20th January 2025. Search screening, data extraction and quality appraisal were all completed by two independent researchers and reviewed collaboratively. The quality of included articles was assessed using the Cochrane Risk of Bias (RoB2) tool and GRADE assessment procedure. Narrative synthesis with meta‐analysis for some outcomes was conducted. Results Sixteen articles, corresponding to 12 RCTs, met inclusion criteria. The quality of data according to GRADE assessment was low for all three outcome types, and RoB high for several included articles. The articles reviewed seven different intervention types. There was evidence that interventions were effective in improving caregiver sensitivity, with the strongest evidence supporting attachment and biobehavioural catch‐up and parent child interaction therapy. There was also limited evidence that interventions may improve placements stability. Overall, there was no evidence that interventions reduce caregiver stress. Conclusions This review demonstrates the effectiveness of interventions in improving caregiver and system level outcomes—both likely to be important mediators for change in the child. Further high‐quality research is needed to identify which interventions are most effective and in what context, with improved consistency in definition and measurement of outcomes.