Across the UK, more than 29% of all children (4.2 million) are living in poverty (Stones, 2023). Consistent evidence has shown that lower childhood household income is linked to poor long-term social, educational and health outcomes (Wickham et al., 2016; The Children’s Society, 2019). This results in a substantial burden on societal and health-care cost. Research explaining the link between early childhood disadvantage, often indicated by childhood poverty, and adverse outcomes is therefore essential, especially those where wider practical and policy implications can be drawn on.
This study by Villadsen and colleagues (2023) aimed to:
- Compare the strength of association between early childhood income and adverse adolescent outcomes
- Examine the maximum potential reductions in adverse outcomes by reducing socioeconomic disadvantage in early childhood.
According to the authors, this was the first longitudinal study to examine the clustering of adverse health and educational outcomes in adolescence as a correlate of early childhood socioeconomic disadvantage, and the first to estimate the potential health and educational gains from reducing socioeconomic disadvantage.
The authors conducted a population-based retrospective cohort study (N= 15,245) using the data from the UK Millennium Cohort study on individuals born between 2000 and 2002. The study assessed five adverse health and social outcomes in adolescence (at aged 17, in 2018), including psychological distress, self-rated health, obesity, regular cigarette smoking, and poor academic achievement. Household income was used as an indicator of early childhood disadvantage. This was averaged across the first three waves (i.e., ages 9 months, 3 years, and 5 years) and transformed into income quintiles for this study.
Five clustering levels were created with people having none, one, two, three, four or five adverse outcomes. The authors then compared how single and multiple outcomes were distributed across early childhood quintile groups of income and modelled the potential effect of three income-shifting scenarios in early childhood for reducing adverse outcomes in adolescence.
- In the first scenario, the authors calculated reductions in adverse outcomes if adolescents in the lowest income quintile group moved up a group, to the next lowest income quintile.
- In the second scenario, the authors moved adolescents in the lowest two income quintile groups to the middle quintile group.
- In the third scenario, the whole cohort was shifted to the same level of adverse adolescent outcomes as those in the highest income quintile group.
Additional analyses were also adjusted for parental education and single parent status.
The population included 15,245 adolescents aged 17 years, with an approximately equal proportion of boys (51.1%) and girls (48.9%). Adolescents in the lowest income quintile had a household income of £117 per week, while those in the highest quintile had a household income of £664 per week. Over 40% of adolescents reported no adverse adolescent outcomes, while 1.7% had experienced four or more adverse adolescent outcomes, equating to over 12,000 additional adolescents per year with extremely poor life chances, signalling a significant long-term burden in terms of financial and human cost.
Adolescents in the lowest childhood household income quintile were almost 13 times more likely to experience four or more adverse adolescent outcomes than those in the highest quintile. The most common adverse outcome of the quintiles was poor academic achievement in the lowest-income quintile. The relative difference between the lowest and highest quintiles were biggest for poor academic achievement and smallest for psychological distress.
Eliminating socioeconomic inequality in early childhood could reduce the burden of multiple adversity by up to 80% and shifting the lowest two quintile groups to the middle could reduce the burden by up to a third. Shifting up the lowest income group to the second lowest income would only reduce multiple adolescent adversities by 4.9%.
When controlling for single-parent status, the effect of household income on the outcomes remained unchanged, except for smoking. When controlling for household education, the effect of household income decreased for poor health, obesity, smoking, poor academic achievement, but increased for psychological distress.
Sex and ethnicity were included as moderators. While there was little gender difference in the pattern of inequality in adverse adolescent outcomes, the authors found that inequalities were slightly greater for White participants compared to their non-White counterparts in terms of having three or more adverse outcomes, suggesting that there may be some protective effects of non-White ethnicity.
The study concluded that poverty in early childhood, indicated by childhood household income, is more strongly associated with multiple adolescent adversities than any individual adverse outcome, highlighting the importance of clustering of health risk factors.
In addition, the findings suggest that a substantial reduction in adolescent adverse health and educational outcomes requires a whole system approach of early childhood inequality reduction rather than simply redistribution of income.
Lastly, the authors drew our attention to the additional barriers facing young people from minority ethnic groups:
the complexities of childhood and multiple interacting and intersecting factors that determine the health trajectories of children growing up in disadvantaged areas.
Strengths and limitations
Similar to other studies using the Millennium Cohort Study data, the study is strengthened by a high-quality, representative population-based longitudinal sample. In addition, as acknowledged by the authors, this was the first study to examine the clustering of outcomes instead of single adverse outcomes. This approach potentially offers a more comprehensive interpretation of how childhood disadvantage can be linked to and interacts with multiple adverse outcomes, from which wider research and policy implications can be drawn on.
There is a lack of clear explanations and rationale for why these adverse outcomes were chosen to be the most representative indicators of adverse outcomes. Similarly, it was not clear on why only parental education and single parent status were included as control variables instead of other relevant factors such as adverse childhood experiences or parental mental health. However, it is acknowledged that the authors wanted to avoid over-adjustment for multiple mediating variables which can bias the analyses.
Although the idea of clustering effects is promising in furthering our understanding of the link between early childhood disadvantage and adverse outcomes, the current analysis did not account for the potential differences in importance and impact of single outcomes, as well as their interactions. It is likely that they will carry different weights and co-vary to a certain extent. Therefore, understanding and focusing on the most significant outcomes is important before we can draw any concrete conclusions or implications.
The study only included biological sex at birth as a moderator in the main analyses, which showed little effects. However, what is arguably more relevant in this context is the adolescents’ sexual identity, which has often been identified as a relevant factor to social and health outcomes (e.g., Kertzner et al., 2009; Clements-Nolle et al., 2018).
Implications for research and policy
The current study offers a great foundation for future research exploring adolescent adverse outcomes following early childhood disadvantage. For example, future studies could explore the weight distribution of single outcomes and/or the interactions between different adverse outcomes and how they can affect the strength of the outcome clusters. Similarly, future studies could also explore the effects of other important confounding variables such as adverse childhood experiences or parental mental health.
As suggested by the authors, the current findings indicate that significantly reducing health and educational outcomes in adolescence requires an ambitious whole system programme of early childhood inequality reduction rather than simply redistributing income. The authors suggested that this includes “the provision of educational and childcare services, reduction of social discrimination and stigma, and other cross-sectoral actions”.
Additionally, the study highlights the need for more inclusive policy in tackling childhood inequalities which take into consideration the multiple intersecting and compounding factors such as ethnicity, gender identity, and other complex needs. Clinicians and professionals working with children and young people with mental health difficulties should be aware of the multitude of inequalities that may compound (or even cause) their distress, and consider how they may need to adjust their approaches to the needs of their service users.
Villadsen, A., Asaria, M., Skarda, I., Ploubidis, G. B., Williams, M. M., Brunner, E. J., & Cookson, R. (2023). Clustering of adverse health and educational outcomes in adolescence following early childhood disadvantage: population-based retrospective UK cohort study. The Lancet Public Health, 8(4), e286-e293.
The Children’s Society. 2019. What are the effects of child poverty? Available from: https://www.childrenssociety.org.uk/what-we-do/our-work/ending-child-poverty/effects-of-living-in-poverty.
Clements-Nolle K, Lensch T, Baxa A, Gay C, Larson S, Yang W. Sexual Identity, Adverse Childhood Experiences, and Suicidal Behaviors. J Adolesc Health. 2018 Feb;62(2):198-204. doi: 10.1016/j.jadohealth.2017.09.022. Epub 2017 Dec 6. PMID: 29223563; PMCID: PMC5803435.
Kertzner, R. M., Meyer, I. H., Frost, D. M., & Stirratt, M. J. (2009). Social and psychological weil‐being in lesbians, gay men, and bisexuals: The effects of race, gender, age, and sexual identity. American Journal of Orthopsychiatry, 79(4), 500-510.
Stone, J. (2023). Local indicators of child poverty after housing costs, 2021/22. Loughborough University. Report. https://hdl.handle.net/2134/23523453.v1
Wickham S, Anwar E, Barr B, et al. Poverty and child health in the UK: using evidence for action. Archives of Disease in Childhood 2016; 101:759-766.