Family income found to be a stronger predictor of health-related problems for 17-year-olds

A new paper in the Journal of Public Health, published by Oxford University Press, finds that household income in early childhood is a stronger and more consistent predictor for several major health-related problems for 17-year-olds than growing up in a poor neighborhood. The neighborhood was a slightly stronger predictor for obesity only.

The Index of Multiple Deprivation, which assesses neighborhoods in the United Kingdom according to factors including unemployment, low levels of education, crime, and barriers to housing and services, has been used widely as a measure of deficiency over the past two decades to guide UK policymakers on health disparities.

The success of the index is due, in part, to its ready availability and linkage to administrative health and other datasets in the country. Household income, however, is the primary indicator of socioeconomic status and is strongly associated with health. Yet household income is challenging for researchers to measure and link to routine health data.

Public health research and prevention policies often use the Index of Multiple Deprivation to try to represent individual socio-economic status. However, the index is a blunt instrument for guiding policies to reduce health inequalities. That’s because some 62% of the poorest households in the United Kingdom live outside the most deprived 20% of neighborhoods. The index also fails to capture the fact that household income is highly responsive to policy changes directly affecting income, such as on wages, benefits, and household costs.

Researchers here used data from the Millennium Cohort Study, a nationally representative retrospective cohort study following people born in the United Kingdom between 2000 and 2002. The first survey in 2001–02 included 18,819 children, followed in subsequent surveys until they reached age 18.

The researchers found that overall, 36.8% of the adolescents surveyed at age 17 achieved poor academic outcomes, 15.3% experienced psychological distress, 7.9% reported poor health, 10.3% were regular smokers, and 18.7% were obese.

The prevalence of all adverse outcomes was characterized by apparent inequality gradients in household income-;moving from the richest to the poorest group, the prevalence of adverse outcomes increased. Poor academic achievement, followed by smoking, exhibited the steepest income inequality gradients consistently across all neighborhood groups. Poor health also showed consistent inequality gradients in income.

But adverse outcomes exhibited moderate to no inequality gradient in neighbourhood groups within each quintile of household income. For example, the prevalence of poor academic achievement showed a moderate inequality gradient across the three middle-income quintiles, indicating that both income and neighbourhood deprivation contribute to poor academic achievement. However, children in the poorest income quintile demonstrated similarly poor attainment regardless of whether they resided in the least or most deprived neighborhoods. Those in the highest income quintile experienced the lowest rates of poor attainment in all neighborhood groups, with minimal variation within the high-income quintile according to neighborhood deprivation levels.

“The Index of Multiple Deprivation is widely used over the last two decades to guide UK policymakers on health disparities,” said Premila Webster, editor-in-chief of the Journal of Public Health. “However, authors of this article have shown that this is a relatively blunt instrument. Family income is a stronger and more consistent predictor for several major health-related problems for 17-year-olds.”