Health Inequality: Examining Public Health Disparities by ZIP Code

Aerial view of New York City with location pins.

“What is the quality of the food that you have access to? What is the quality of the environment that you have access to? What are your opportunities for greater access to green space where you can go out and exercise and feel safe?” Your responses to these and similar questions might predict your health and well-being, according to Dr. Thomas LaVeist, dean of the Tulane University School of Public Health and Tropical Medicine, whose research centers on why some groups in the United States are healthier than others based on factors such as food deserts, lack of access to green space, crime, and insufficient health care options—factors that are represented in health disparities by ZIP code.

Health Differences Versus Health Disparities

Everyone wants to live a long, healthy life. In the United States, however, some people have better chances than others. The life expectancy of a person born in the U.S. in 2017 was 78.6 years, ranking last among countries of comparable wealth and size, according to a 2019 study by the Organisation for Economic Co-operation and Development, based in France. Public health leaders and other experts want to know why the U.S. ranks so low on the ladder, and they see health disparities as a driver of the rankings.

What’s the distinction between a health difference and a health disparity? According to U.S. public health organizations, including the American Public Health Association (APHA), many differences in health outcomes (e.g., the likelihood of developing cancer, diabetes, or chronic hypertension) are fundamental, resulting from unavoidable factors such as aging. Health disparities, on the other hand, result from the uneven and unfair distribution of social resources.

For example, U.S. African American women in the United States experience more than triple the rate of death in childbirth than U.S. white women. This health disparity is rooted in many cultural and historical influences, including bias among healthcare workers that can lead to mis- or under-diagnosis and other social factors that limit access to adequate prenatal care.

Tackling Disparities with Place-Based Health

Multiple studies show that place — not just physical location but the type of social environment in which people grow up, live, and work — is a prime factor in how well people thrive. Dean LaVeist and other public health leaders have made it their mission to address health inequities resulting from disparities like this by researching an approach known as place-based health.

Place-based health initiatives focus on the social determinants of health (SDOH), which Healthy People 2020 defines as “conditions in the environments in which people are born, live, learn, work, play, worship, and age that affect a wide range of health, functioning, and quality-of-life outcomes and risks.”

Public Health by ZIP Code and Social Determinants of Public Health

Healthy People 2020 outlines five key domains related to people’s physical and social environments and how they affect health outcomes:

  • Neighborhood and built environment: The connection between where people live and their health. Key issues are nutrition, safe housing, interpersonal violence, and physical environmental conditions, such as exposure to pollution or noise.

  • Social and community context: The connection between people’s social support, including family circumstances and community engagement, and their health. Key issues are community participation, incarceration of a family member, and discrimination.

  • Economic stability: The connection between people’s financial circumstances, including income and cost of living, and their health. Key issues are poverty, employment, food security, and housing stability.

  • Education: The connection between people’s education and their health. Key issues are high school graduation, higher education, literacy, and access to early childhood education.

  • Health and health care: The connection between people’s access to health care and their health. Key issues are ease of access to health care (affordability, transportation, etc.) and health literacy.

Place, Not Race

What would happen if disparities in social determinants could be equalized? In his 2011 study of the health outcomes of African Americans and white individuals in Baltimore, Dean LaVeist weighed the influence of key social determinants of health on race and found that when these two racial groups lived under similar circumstances, differences in health were much less than when their living conditions were dissimilar. Dean LaVeist and his colleagues concluded from this study that “when social factors are equalized, racial disparities are minimized,” an insight he expresses as “place, not race.”

“We’ve got huge disparities in access to health insurance as well as huge disparities in access to health care,” Dean LaVeist explains. “It is a part of the puzzle. It is not the only reason that racial disparities exist, but it is certainly a part of the issue. African Americans have the worst health profile of any group in the country, and my work has been focused on trying to understand why that is and what we can do about it. How do we intervene to make things better?”

As Dean LaVeist sees it, differences in life experience often contribute to public health disparities, even between neighboring communities. “The experience is so different, and that is what drives the disparities in health. Because of that, the lifestyles are different, the resources are different, and the health outcomes are different,” he says. “It’s not something genetic or something like that — it’s really more about environmental exposures.”

Why do some populations experience far lower health status than others? What specific factors cause this unfair disparity in our nation? According to thought leaders in public health such as Dean LaVeist, joblessness; lack of access to quality education, adequate housing, or social support; and exposure to crime and violence, for example, are the result of systemic injustice reaching back centuries. When communities struggle with these kinds of inequities — and the health disparities that can result from them — place-based health and other social policies can help bring balance, leading to better health outcomes for all.

One motive for enacting place-based health initiatives is practical: A healthier nation with reduced rates of chronic illness would have lower medical expenses and higher productivity, according to the APHA. But to Tulane University’s Dean LaVeist, the incentive for addressing the problem goes much deeper: “If we don’t invest in all of our people equitably, we don’t get the full benefit of the collective genius of the entire society.”

Acting on Place-Based Health at Tulane

Acknowledging and addressing systemic injustice and consequent health disparities is an ongoing battle in our nation, with tenacious public health leaders at the frontlines. Understanding location’s influence on health equity in the U.S. is just part of the picture. At Tulane University, Dean LaVeist and other dedicated researchers and public health leaders focus on understanding underlying causes of health disparities. Tulane University’s Online Master of Public Health prepares students to be culturally competent public health professionals and equips them to challenge persistent social inequities in healthcare access. Discover how you can prepare yourself to help address place-based health inequities and bring about health equity for all. Explore Tulane University’s Online Master of Public Health.