Foster Care and Health in Medicaid-Enrolled Children Experiencing Parental Opioid Use Disorder.

Importance: The burden of the US opioid crisis has fallen heavily on children, a vulnerable population increasingly exposed to parental opioid use disorder (POUD) in utero or during childhood. A paucity of studies have investigated foster care involvement among those experiencing parental opioid use during childhood and the associated health and health care outcomes. Objective: To examine the health and health care outcomes of children experiencing POUD with and without foster care involvement. Design, Setting, and Participants: This population-based cohort study used nationwide Medicaid claims data from January 1, 2014, to December 31, 2020. Participants included Medicaid-enrolled children experiencing parental opioid use-related disorder during ages 4 to 18 years. Data were analyzed between January 2023 and February 2024. Exposure: Person-years with (exposed) and without (nonexposed) foster care involvement, identified using Medicaid eligibility, procedure, and diagnostic codes. Main Outcomes and Measures: The main outcomes included physical and mental health conditions, developmental disorders, substance use, and health care utilization. The Pearson χ2 test, the t test, and linear regression were used to compare outcomes in person-years with (exposed) and without (nonexposed) foster care involvement. An event study design was used to examine health care utilization patterns before and after foster care involvement. Results: In a longitudinal sample of 8 939 666 person-years from 1 985 180 Medicaid-enrolled children, 49% of children were females and 51% were males. Their mean (SD) age was 10 (4.2) years. The prevalence of foster care involvement was 3% (276 456 person-years), increasing from 1.5% in 2014 to 4.7% in 2020. Compared with those without foster care involvement (8 663 210 person-years), foster care involvement was associated with a higher prevalence of developmental delays (12% vs 7%), depression (10% vs 4%), trauma and stress (35% vs 7%), and substance use-related disorders (4% vs 1%; P < .001 for all). Foster children had higher rates of health care utilization across a wide array of preventive services, including well-child visits (64% vs 44%) and immunizations (41% vs 31%; P < .001 for all). Health care utilization increased sharply in the first year entering foster care but decreased as children exited care. Conclusions and Relevance: In this cohort study of Medicaid-enrolled children experiencing parental opioid use-related disorder, foster care involvement increased significantly between 2014 and 2020. Involvement was associated with increased rates of adverse health outcomes and health care utilization. These findings underscore the importance of policies that support children and families affected by opioid use disorder, as well as the systems that serve them.