Cardiovascular Disease Events in Adults with a History of State Care in Childhood: Pooling of Unpublished Results from 9 Cohort Studies

Background: Individuals who were separated from their biological family and placed into the care of the state during childhood (out-of-home care) are more prone to developing selected physical and mental health problems in adulthood, however, their risk of cardiovascular disease (CVD) is uncertain. Accordingly, we pooled published and unpublished results from cohort studies of childhood care and adult CVD. Methods: We used two approaches to identifying relevant data on childhood care and adult CVD (PROSPERO registration CRD42021254665). First, to locate published studies, we searched PubMed (Medline) until November 2023. Second, with the aim of identifying unpublished studies with the potential to address the present research question, we scrutinised retrieved reviews of the impact of childhood state care on related adult health outcomes. All included studies were required to have prospective measurement of state care in childhood and a follow-up of CVD events in adulthood as the primary outcome (incident coronary heart disease and/or stroke). Collaborating investigators provided study-specific estimates which were aggregated using random-effects meta-analysis. The Newcastle-Ottawa Scale was used to assess individual study quality. Findings: Thirteen studies (2 published, 11 unpublished) met the inclusion criteria, and investigators from nine provided viable results, including updated analyses of the published studies. Studies comprised 611,601 individuals (301,129 women) from the US, UK, Sweden, Finland, and Australia. Relative to the unexposed, individuals with a care placement during childhood had a 50% greater risk of CVD in adulthood (summary rate ratio after basic adjustment [95% confidence interval]: 1.50 [1.22, 1.84]); range of study-specific estimates: 1.28 to 2.06; I2 = 69%, p = 0.001). This association was attenuated but persisted after multivariable adjustment for socioeconomic status in childhood (8 studies; 1.41 [1.15, 1.72]) and adulthood (9 studies, 1.28 [1.10, 1.50]). There was a suggestion of a stronger state care-CVD association in women. Interpretation: Our findings show that individuals with experience of state care in childhood have a moderately raised risk of CVD in adulthood. For timely prevention, clinicians and policy makers should be aware that people with a care history may need additional attention in risk factor management.