Mediation by childhood adversity

Children born into disadvantaged socioeconomic circumstances are more likely to experience both adversity during childhood and premature mortality. We used the DANLIFE cohort to investigate how much of the parental education gradient in early adult mortality is explained by exposure to childhood adversity.

Our sample consisted of all individuals born between Jan 1, 1980, and Dec 31, 2001 (N=1,278,156) who were followed in terms of mortality from age 16 years until Dec 31, 2018. The highest attained parental education level at birth was divided into low (≤9 years), medium (10–12 years), and high (>12 years) according to years in education. Individuals were assigned to one of five childhood adversity trajectory groups based on their annual exposure between age 0 and 16 years to a broad selection of adversities in three dimensions: material deprivation, loss or threat of loss in the family, and family dynamics.

During follow-up, 5387 deaths were registered. Compared with the high parental education group, we calculated a total effect equal to 8.7 additional deaths (95% CI 6.6–10.9) per 100,000 person-years in the medium parental education group and 31.9 (28.5 to 35.2) per 100,000 person-years in the low parental education group. Mediation through childhood adversity trajectories accounted for 41.5% (95% CI 8.0–67.5) of the additional deaths in the medium parental education group and 46.4% (32.9–58.8) of the additional deaths in the low parental education group.

We conclude that the experience of childhood adversity seems to be an important mediator of the association between parental education and mortality in early adulthood. Interventions reducing the exposure to childhood adversity might thus reduce the parental education gradient in early adult mortality.

Cemetery
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