Socioeconomic inequalities in older adults’ health: The roles of neighborhood and individual-level psychosocial and behavioral resources

Health inequalities in older adults are a critical health issue given the fact that the proportion of older adults is growing fast in virtually every country worldwide (1). Health inequalities can be understood as differences in health between groups defined by social structural variables, such as education, income, or ethnicity (2). Generally, individuals with lower socioeconomic status (SES) experience worse overall health, higher levels of morbidity, and more premature mortality, which are particularly relevant in older adults (3–6). There are two competing approaches to understanding inequality effects on health over the lifespan. The cumulative advantage/disadvantage hypothesis proposes that social disadvantage accumulates over the lifespan, leading to more inequality in a range of health outcomes in older age—depending on which indicator of inequality is examined (5, 6). In contrast, the age-as-leveler hypothesis assumed that socioeconomic differences in health between individuals decrease with older age due to more equity through pensions and healthcare in old age (7, 8). Given that socioeconomic differences in health outcomes are potentially avoidable (9), it is particularly important to examine the roles of socio-economic, socio-psychological, and behavioral resources in alleviating health inequalities among older adults from different SES backgrounds (10). While the overall picture seems clear—lower socioeconomic status is associated with overall worse health, less is known about the association of specific indicators of SES, and health (4). Here in particular, differential effects of individual-level inequality dimensions such as education or wealth, and inequality dimensions determined by an individual's environment can be expected (5). Individual-level indicators of SES might carry information with regards to individual resources, access, and information processing capabilities. Environmental indicators are related to the built or social environment, such as differences in social cohesion, differences in physical access to and availability of social support and other environmental factors (e.g., street connectivity, mixed land use, and inclusion of green spaces) (11, 12). What is more, environments can change over the course of time, as individuals are for example exposed to different environmental factors at work compared to their home, or on the commute—so called momentary environments (13). Of particular interest in this context is the existence and shape of interactions between individual and neighborhood-level SES. In general, living in a less disadvantaged neighborhood seems to profit health above and beyond individual measures of inequality (14). That is, lower SES individuals might benefit more from living in higher SES neighborhoods than individuals with higher SES. The idea is that restrictions in access to health-related resources through individual-level disadvantage, such as lack of funds for medical treatments, could be buffered by district-level resources, such as access to a neighborhood-level resource (e.g., community health nurse) (14). Although the influence of neighborhood-level SES on health is smaller than individual-level SES, it has been demonstrated that systematic health inequalities exist between neighborhoods differing in SES (11). Individuals living in more affluent neighborhoods experience better health and lower rates of mortality and morbidity than those living in more disadvantaged areas (11). This highlights that the field requires a more systematic approach toward examining the relationship between SES and health on multiple levels to develop and improve health promotion and disease prevention programs from an early stage (15). However, it is unclear how individual-level SES, neighborhood SES, and their interactions affect older adults' health.