Socioeconomic pathways to inequalities in mental and functional health: a comparative study of three birth cohorts.

Background: Although the educational expansion is often seen as a mechanism that might reduce health inequalities, socioeconomic inequalities in health (SEIH) have persisted or increased over the past decades. Theories suggest that this persistence could be due to a changing role of education as a 'gatekeeper' to access other socioeconomic resources such as occupation and income that are also associated with health outcomes. To test this, we examine whether the mediating role of occupation and income in the education-health relationship differs between three cohorts of 55-64 year old adults.

Methods: We used cross-sectional data from three cohorts of 988, 1002, and 1023 adults born in 1928/37, 1938/47 and 1948/57 and observed in 1992/93, 2002/03, 2012/13 respectively, who participated in the Longitudinal Aging Study Amsterdam, the Netherlands. We used multigroup structural equation modelling to compare the strength of indirect effects of education via occupational skill level and income to functional limitations and depressive symptoms between cohorts.

Results: Absolute educational inequalities in functional limitations increased for men and women in later cohorts, and in depressive symptoms only for men. Relative inequalities in functional limitations increased only for women and in depressive symptoms only for men. The indirect effect of education via income on both health outcomes was weaker in the most recent birth cohort compared to the earlier cohorts. In contrast, the indirect effect of education via occupation on functional limitations was stronger in the most recent cohort compared to the earlier cohorts. These differences were mainly due to a decreasing direct effect of education on income and an increasing direct effect of education on occupational skill level, rather than to changes in the direct effects of occupation and income on health.

Conclusions: The role of education in determining inequalities in health appears to have changed across cohorts. While education became a less important determinant of income, it became a more important determinant of occupational level. This changing role of education in producing health inequalities should be considered in research and policy.