Socioeconomic Status Trajectories and Later Life Physical Health

Background and Purpose: Chronic diseases are the primary causes of poor health, disability, and death, and account for most of the health-care expenditures among the rapidly aging U.S. population (Bauer, et al., 2014). With a potentially long latent period of aging-related illness, there is convincing evidence demonstrating that exposures in different stages of life have a lasting impact on the health and illness of older adults (Kuh & Shlomo, 2003). In particular, socioeconomic status (SES) throughout the lifecourse has enormous potential to influence health in later life (see Link & Phelan 1995; Phelan, Link & Tehranifer 2010). For instance, childhood and adult SES was observed to contribute to mortality from coronary heart disease, lung cancer, cardiovascular disease and respiratory-related disease (Galobardes, Lynch, & Smith, 2004; 2006). However, few studies have explored both the continuous influence and relative impact of SES across different life stages on physical health in later life. This study examines the influence of SES during early, middle, and later life on aging-related physical health using an innovative longitudinal dataset.  The variation in the relationship between lifecourse SES and later life physical health by gender are also discussed.

Methods: We examine the links between socioeconomic status and physical health in later life using the Wisconsin Longitudinal Study (WLS), a prospective cohort study following high school graduates from Wisconsin schools in 1957. The independent variable of interest is SES from the family of origin in 1957, including both head of household education level and income tercile. We also look at the impact of educational attainment for respondents, as well as family income and individual earnings at different points in the lifecourse (working age, age 65, and age 72). We are able to examine socioeconomic trajectories throughout the lifecourse with these measures. The measures of physical health come from survey interviews at approximate age 72 in 2011 and include:  general self-rated health (fair or poor vs. excellent, very good or good health), diabetes, and hypertension. We are able to control for childhood health, adolescent and adult BMI, and a wide variety of health behaviors. We estimate odds ratios using gender stratified logistic regression models for each of the health outcomes.

Results: We find a statistically significant relationship between low SES in adolescence for women (odd ratios reported for low family income as independent variable) for poor/fair general health (OR=1.6), diabetes diagnosis (OR=1.4), and hypertension diagnosis (OR=1.3) in models that also include adult SES. We find no relationship between early life SES and physical health for men. Low SES in adulthood had a significant relationship with all three health measures for both women and men, though the magnitude of the relationship was not as strong as early life SES for women.

Conclusions and Implications: Early life SES has a lasting impact on physical health, but only for women, adding further evidence to the growing body of research suggesting that women are particularly susceptible to lifecourse conditions that shape health disparities.