of the target population in four communities: the Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA. The study enrolled participants from diverse national backgrounds, including Cuban, Dominican, Puerto Rican, Mexican, Central American, and South American.
Using data from HCHS/SOL, Kershaw and colleagues used two easily assessable measures of acculturation to investigate the relationship between acculturation level and favorable levels of cardiovascular risk factors [28]. They used nativity and years lived in the United States to derive a three‐level acculturation variable: (i) low acculturation: foreign‐born and lived in the United States less than 10 years, (ii) moderate acculturation: foreign‐born and lived in the United States equal to or more than 10 years, and (iii) high acculturation: US‐born. Among cardiovascular risk factors, the study assessed cholesterol levels, systolic and diastolic blood pressure, fasting plasma glucose, current smoking, electrocardiograph abnormalities, and stress due to ethnic discrimination.
Results from multivariable‐adjusted models showed that low‐acculturated women had significantly higher odds of favorable levels of cardiovascular risk factors compared to moderate‐ or high‐acculturated women. Further, favorable levels of cardiovascular risk factors differed significantly among men by their national background. For example, moderate‐acculturated Dominican men had significantly higher odds of favorable levels of cardiovascular risk factors compared to their low‐acculturated counterparts.
One of the limitations of this study is its cross‐sectional design and, therefore, inability to examine changes in health behaviors over time and determine temporality. The HCHS/SOL study has longitudinal follow‐up and will eventually be able to assess these factors over time. Another limitation is that the study may have overadjusted for covariates that may be on the causal pathway between acculturation level and favorable levels of cardiovascular risk factors.
Despite these limitations, the present study exhibits how acculturation level can influence established risk factors for chronic health conditions and how that relationship can differ among subpopulations of immigrants.
3.5.3 Pittsburgh Hill/Homewood Research on Neighborhoods and Health Study
The Pittsburgh Hill/Homewood Research on Neighborhoods and Health (PHRESH) study evaluates a natural experiment of neighborhood revitalization on health in Black communities. To reduce inequalities in food access, policy solutions have concentrated on addressing the issue of “food deserts,” or neighborhoods with inadequate access to healthy, affordable foods. One proposal has been to place full‐service supermarkets in neighborhoods with limited access to healthy food. To better understand how this solution may lead to changes in diet, Dubowitz and colleagues conducted a rigorous study in Pittsburgh, PA that surveyed two predominately Black sociodemographically similar neighborhoods. The PHRESH study uses a quasi‐experimental longitudinal design. One of the study neighborhoods received a new supermarket, and the other acted as a control in order to understand if the introduction of the supermarket led to improved dietary outcomes. Data were collected using surveys with randomly selected residents, which included two 24‐hour dietary recalls administered between seven to fourteen days apart [29].
The study results showed net positive changes in overall dietary quality; average daily intakes of kilocalories and added sugars; and percentage of kilocalories from solid fats, added sugars, and alcohol in the neighborhood that received a full‐service supermarket [29]. However, the only positive outcome in the recipient neighborhood specifically associated with regular use of the new supermarket was improved perceived access to healthy food. The researchers did not observe a significant increase between the neighborhoods in fruit and vegetable intake, whole grain consumption, or body mass index. Though the introduction of supermarkets in food deserts is appropriate, the mechanisms for understanding how the introduction of such supermarkets may influence dietary behaviors and weight status requires further study. Policymakers considering the approach of introducing full‐service supermarkets in food deserts should include assessments of other community‐level mechanisms that may affect both store users and nonusers. Finally, future assessments should consider longer‐term follow‐ups, which may allow for changes in weight status to be detected [29].
Another PHRESH study examined neighborhood walkability. Previous studies have found that Black adults are not likely to get the recommended amount of daily moderate to vigorous physical activity (MVPA) [30], which is known to be an important factor for lowering diastolic blood pressure [31] and for reducing the risk of cardiovascular disease and risk factors [32]. In a study conducted by Richardson and colleagues using data from the PHRESH study, it was hypothesized that low levels of MVPA (where accelerometry was used to measure physical activity, which is superior to self‐reporting) among Black adults may be associated with crime rates, the amount of green space, and walkability in one's neighborhood [30]. In addition to data from PHRESH, the study examined crime data available from the City of Pittsburgh and used ArcGIS to calculate street network distances from households to crime locations. The team hypothesized that crime occurring in the previous year would influence perceptions of safety. The team studied the relationship between these three variables (i.e., neighborhood green space, walkability, and crime) and their influence on MVPA, as well as a potential interaction effect.
The results suggested that, although all residents engaged in little MVPA, women under the age of 65 living in more walkable neighborhoods engaged in significantly more MVPA. The variables green space and crime were not associated with MVPA in this study. However, there may have been limited power to detect associations between neighborhood characteristics and MVPA. Future studies are required to increase knowledge regarding the impact of lifestyle and neighborhood factors (e.g., walkability, green space, and crime) and their interactions on MVPA to inform public health policy [30].
3.6 Challenges and Future Opportunities
3.6.1 Biological Links to Social Determinants
One of the major challenges that researchers face is understanding how the social determinants of health get “under the skin” to impact health. This requires studies to link specific social determinants of health to biological mechanisms. Several developing research areas aim to investigate such links as epigenetic markers, and how heritable and potentially modifiable changes in gene expression can be affected by nonbiological and environmental exposures [33]. Other examples include biological markers of stress, such as cortisol or telomere length, as a marker for cellular aging. These issues will add to the ongoing complexity of health disparities research. Nonetheless, continuing to develop new methods to elucidate mechanisms will be crucial in the quest to eliminate health disparities.
3.7 Summary
This chapter focused on summarizing the state of the literature, measurement issues, and research opportunities related to race, SES, and other social determinants. The chapter references two conceptual frameworks in order to provide an understanding of the factors involved in the relationships between race/ethnicity, SES behavioral mediators/moderators, and health outcomes. The use of widely accepted measures, such as those used by the US Census Bureau, is critical to minority health and health disparities research because they make it possible to compare findings across studies and over time.
The differences between race and ethnicity are distinct, although they can be difficult to distinguish if one is not intimately familiar with them. As the United States becomes more diverse, future health research will need to disaggregate the larger racial/ethnic categories to understand the causes of known differences in health status, behaviors, and outcomes between subgroups. Among the key measures of health are mortality, morbidity, and life expectancy, which can be used to gauge progress in improving minority health and in reducing health disparities.
One
