Abstract
Foster care is the preferred type of out-of-home placement for children and youth when they are not able to live with their own parents. However, placement instability, and its effect on children's behavioral well-being, remains a major issue in foster care. Ten multilevel meta-analyses were performed to examine factors that can affect instability of foster care placement. We included 42 studies (published between 1990 and 2017) examining putative factors associated with placement instability, which yielded 293 effect sizes. Indications of publication bias were found, but the trim and fill procedure confirmed the main findings. Medium significant effects were found for child behavioral problems (r = 0.35), (non-)kinship care (r = 0.31), and quality parenting (r = 0.29). Smaller effects were found for age of the child (r = 0.25), placement with(out) siblings (r = 0.16), and history of maltreatment of the child before placement (r = 0.14). The effects were generally modest, but showed generalizability across continents and time. The findings can be used to improve interventions for the prevention of placement instability in foster care, and further investigations.