Out-of-home care and criminal conviction trajectories from adolescence to midlife: A Swedish prospective cohort study of siblings

BACKGROUND: Out-of-home placed children face elevated risks of criminal trajectories. The magnitude of this association, after accounting for shared measured and unmeasured familial and environmental factors, remains unclear. OBJECTIVE: This prospective study examined criminal trajectories from adolescence to midlife and their association with placement, while adjusting for shared confounders within sibling groups. PARTICIPANTS AND SETTING: Swedish register data covering all children born between 1972 and 1979 (N = 804,553) were used to follow siblings differentially exposed to out-of-home care from birth to age 40 (n = 14,762). METHODS: Sex-stratified Latent Class Growth Analysis identified conviction trajectories from age 15 to 40. Associations with out-of-home care were estimated using multilevel multinomial logistic regression analysis models that accounted for sibling-level clustering. RESULTS: 45.58% of men (n = 3709) and 15.63% of women (n = 1114) had one or more convictions. The following trajectory groups emerged: low decreasing (70.60%) and high stable (6.80%) in men, low increasing (23.00%) and high increasing (8.90%) in women, and high decreasing in both sexes (22.50% for men, 68.20% for women). All trajectories were more likely to be followed by those placed as adolescents than non-placed individuals (AMEs: 3%-18%), even after adjusting for shared measured and unmeasured familial and environmental factors. There was moderate trajectory clustering within families (ICCs: 0.14-0.17). CONCLUSIONS: Out-of-home placement, particularly in adolescence, is robustly associated with adverse criminal trajectories from adolescence to midlife, even among siblings sharing a substantial familial liability for crime. Early and developmentally sensitive interventions may help mitigate this.