This 5‐year prospective population‐based study showed a graded association between childhood adversities and increased incidence of disability retirement. After simultaneous adjustments for various other risk factors (low SES, depression, drugs for somatic diseases, health‐related risk behaviour), the association between childhood adversities and the risk of disability retirement attenuated, but remained significant, showing a dose–response relationship. Earlier research on the effect of adverse childhood experiences on the risk of disability retirement is scarce and has ignored the potential cumulative effects of multiple childhood adversities on the risk of disability retirement.
Our findings are in accordance with the results of the previous study where unfavourable conditions during childhood and adolescence predicted disability pension and long‐term absence due to sickness in adulthood among Swedish women.8
Early disability pensions and conditions during childhood and adolescence among young Swedish men were previously studied.9
In this study, it was concluded that unfavourable conditions during childhood and adolescence were of major importance in understanding the social class gradient in disability pensions among young men. As suggested in these previous studies, conditions during childhood may affect health behaviour and conditions during adult life. Our results also highlight the importance of early‐life exposures to the later risk of chronic diseases and disability retirement.
What this paper adds
- Previous studies on the determinants of retirement due to disability have concentrated on adulthood risk factors such as poor physical health and low socioeconomic status.
- Extending the focus also to cover potential determinants from early‐life circumstances may increase our understanding of the complex process and determinants of early retirement, especially owing to mental disorders.
- Our study shows that the risk of disability retirement increases in a dose–response manner with increasing number of childhood adversities.
- After adjustments for adulthood risk factors, such as low socioeconomic status and health‐related risk behaviour, the association between childhood adversities and the risk of disability retirement attenuated, but remained significant.
A life‐course approach provides three conceptual models to interpret associations between early‐life exposures and adult health.4,14
The latency model suggests a direct effect of childhood conditions on adult health regardless of conditions during adult life, the pathway model proposes an indirect effect maintaining that childhood conditions affect adult health through adult conditions and the cumulative model assumes that both childhood and adulthood conditions are important to adult health.4,6,15
In our study, the association between childhood adversities and the risk of disability retirement attenuated, but remained significant after simultaneous adjustments for low SES, health‐related risk behaviour, depression and use of drugs for somatic diseases. This finding supports the latency model. However, additional adjustments for depression and health‐related risk behaviour decreased the odds of disability retirement for childhood adversities more than any other adult risk factor, suggesting that, especially, mental problems and risk behaviour in adulthood, at least partly, mediate the effect of childhood adversities on the risk of disability retirement, a finding in accordance with the pathway model. As multiple factors in adulthood also remained significant predictors of disability pension, our study is also in line with the cumulative model.
Adverse childhood experiences were previously associated with decreasing optimism in adulthood in a dose–response manner, suggesting that the more adverse the childhood experiences, the more profound the effects on the development of personality.11
It is evident that disability retirement is affected by many individual and societal factors, but exposure to negative emotional events during childhood may affect the way of coping with the negative life events in adulthood and increase the risk of depression and disability retirement, especially due to mental disorders. However, this potential mechanism could not be tested in this study.
Our findings that low SES, depression, drugs for somatic diseases, smoking, heavy alcohol consumption and obesity increased the risk of disability retirement, are in line with the results of the previous studies on the risk factors of disability retirement.16,17,18,19,20,21,22,23
As shown in an earlier study conducted with this population sample,5
childhood adversities was strongly correlated with depression in adulthood. In addition, childhood adversities were associated with other known risk factors of disability retirement: lower SES, use of drugs for somatic diseases, current smoking, heavy alcohol consumption and obesity.
- The significance of childhood adversities should be taken into account when considering both the determinants of disability retirement and identifying groups at risk.
- Our findings highlight the longlasting effect of childhood circumstances on adult health and functioning.
- Thus, early‐stage recognition and prevention of adverse childhood circumstances should be promoted.
The strength of our study includes the large nationwide population sample with a prospective study design and good response rate of the follow‐up questionnaire (80.2%, year 2003). According to a non‐response analysis at follow‐up, loss to follow‐up was higher in men, in younger age groups, in lower SES groups and among those with at least moderate depression, those who smoke and heavy alcohol consumption. However, the differences between respondents and non‐respondents were relatively small, and thus we consider a major selection bias unlikely. The comprehensive questionnaire and repeated measures offered us excellent opportunities to consider general significant covariates including health‐related behaviour and mood‐related measures. However, the possibility of residual confounding by unmeasured factors cannot be eliminated. Further research is needed, for example, to take into account influence of genetic and fetal exposure, as indicated by birth weight and maternal smoking in pregnancy (data on these variables were not available).
A weakness of the study is a relatively low baseline response rate. However, a careful non‐response analysis at baseline (year 1998) indicated that the most important demographic and the physical health‐related differences between the respondents and the non‐respondents were small.10
The retrospective nature of the question on childhood adversities may also be considered a weakness in this study. However, the reliability of the answers on childhood adversities was tested in a previous study conducted with this population sample.7
The κ coefficient varied between 0.56 and 0.90, which indicates that retrospective data on childhood adversities are likely to be reliable. Long‐term regular use of drugs can be regarded as a relatively reliable measure of chronic somatic diseases.24
In addition, the regular use of drugs for somatic diseases was strongly associated with the risk of disability retirement. However, misclassification because of undiagnosed morbidity and illnesses not requiring drugs remains a potential source of error that may lead to underestimation of associations. An additional weakness is that, on the basis of current data, we have no knowledge of the reasons of retirement and deaths during the follow‐up period. In 2003, the main reasons for disability retirement in the same age groups used in this study were musculoskeletal (35%), mental (26%) and cardiovascular diseases (11%).25
The lack of data on mortality presumably attenuated the associations found in this study.