Scientists, physicians, policy makers, and others are now considering the total ecology of population health outcomes, which include complex, integrated, and overlapping social structures and economic systems, collectively referred to as social determinants of health (SDH).
1 SDH are the economic and social conditions that influence the health of people and communities as a whole.
1–3 Research continues to show that personal choices or behaviors are only part of what determines individual health status.
1,4,5 Five determinants of population health are generally recognized in scientific literature:
- Biology and genetics (e.g., gender and race)
- Individual behavior (e.g., alcohol use, injection drug use, unprotected sex, and smoking)
- Social environment (e.g., discrimination, ethnicity as it applies to social customs and traditions, income, education level, and marital status)
- Physical environment (e.g., place of residence, crowding conditions, and the built environment)
- Health services (e.g., access to quality care, insurance status, and previous diagnosis of a health-related outcome [which serves as a proxy for determining how often an individual has been in contact with the system to manage symptoms])1,6,7
The last three categories are associated with SDH. Genetics and individual behavior affect the individual's environment in ways that are unique to the individual, but as such, the risk for disease is greater when associated with inequitable distribution of income, access to health care, and environmental concerns.
4,5SDH have been implicitly understood as underlying causes of disease, yet only in the last decade or so has rigorous research been conducted to better understand SDH variables that play major roles in population health (including minority health).
8–10 SDH include social factors that strongly impact morbidity and mortality; discrimination on the basis of race, ethnicity, gender, or sexual orientation; cultural customs, traditions, language, beliefs, and norms; and access to education and health resources.
3,11–21 Populations that typically experience lower income levels are more likely to have lower education levels; live in densely populated areas, remote rural areas, or areas with little or no access to healthier food outlets and markets; experience violence and poorer sexual health outcomes; have no or inadequate health insurance; and be employed in positions that are more labor-intensive with fewer opportunities for upward mobility.
11,12,14–16,22–27 Having data to address and monitor the prevalence of these factors and their individual contributions to health outcomes is important in understanding disease incidence as well as developing interventions. However, despite this need, there is a lack of appropriate SDH and disease outcome analyses to quantify the contribution of SDH variables to specific outcomes of interest.
28 The need for an increased focus on the science of SDH as an approach to achieving health equity has been identified as an area of importance by the World Health Organization (WHO), the Institute of Medicine, the U.S. Department of Health and Human Services, and the Centers for Disease Control and Prevention (CDC).
3,7,28,29A number of models describe the relationships between determinants of health and health status. WHO convened the Commission on Social Determinants of Health (CSDH) in 2005 to support partners in addressing SDH in their public health efforts. The CSDH created a model, released in 2008 with its final report, that describes the overlapping, multidirectional pathways that allow SDH—when combined with social capital, political influences, individual traits, and the health-care system—to affect health outcomes.
3Another popular SDH model developed by Ansari et al. demonstrates the relationship among health-care systems, SDH, behaviors, and health outcomes, and the dynamic relationship between psychological risks and the effects of socioeconomic determinants.
1,30 Dahlgren and Whitehead also created a relatively simple model that builds upon the influence of biology, individual behaviors, SDH, and health outcomes.
1,31More recently, the Health Impact Pyramid, developed by Frieden, shows the influences on overall population health, beginning with socioeconomic factors. Each layer builds upon those factors, including changing the context of health decision-making, interventions, and education. Each higher level results in a lesser influence on health outcomes, but a more feasible target for individual-level interventions. It is important to note that in the Health Impact Pyramid, achieving improved population health requires the most attention to influences that are out of the individual's control, such as the underlying social and economic factors.
32Health disparities in human immunodeficiency virus (HIV), viral hepatitis, sexually transmitted diseases (STDs), and tuberculosis (TB) have been documented for racial and ethnic minority groups, sexual and gender minority groups, young people, females, and incarcerated people.
33–35 SDH may explain the common co-occurrence of risk factors among these groups and, thus, the co-occurrence of diseases such as HIV, hepatitis, and STDs, and, in some populations, TB and HIV. Current challenges exist in the study of SDH due to limited comparability of population-based U.S. data on SDH because of differences in measurements of disparity and data quality.
3,13,16,18,28,36–38 Multiple national health and science agencies are calling for increased surveillance capabilities and increased data reporting to obtain a more complete picture of population disease, to identify the underlying causes of morbidity and mortality, and to reduce the stigma associated with certain diseases.
1,3,28For this project, we identified SDH measures collected in CDC's population-based surveillance systems for HIV, viral hepatitis, STDs, and TB and provided recommendations for the collection of supplemental SDH variables. We also scanned the literature to determine the evidence for consistent associations between SDH and these four diseases and to help inform our recommendations.