The Interwoven Threads of Inequality and Health

People in a spread out line.
The coronavirus crisis is revealing the inequities inherent in public health due to societal factors, Nancy Krieger, a professor of social epidemiology, says.Photograph by Johannes Eisele / AFP / Getty

According to preliminary data about the coronavirus pandemic, African-Americans are bearing a strikingly disproportionate share of the suffering in the United States. In Illinois, where fourteen per cent of the population is African-American, black Americans represent more than forty per cent of the state’s confirmed coronavirus deaths. Coronavirus fatalities have a similar breakdown in Michigan, and several Southern states show even greater disparities. The possible reasons for these inequities are myriad: African-Americans are less likely than white Americans to have the option of working from home and to receive high-quality medical care, and more likely to have preëxisting medical conditions that lead to worse outcomes from the novel coronavirus. New research links coronavirus deaths to air quality, which is often worse in poor communities and communities of color.

Nancy Krieger is a professor of social epidemiology at the Harvard T. H. Chan School of Public Health. Her work focusses on health disparities between demographic groups and the social structures that help determine those disparities. We recently spoke by phone about how American health inequities are playing out during the pandemic. During our conversation, which has been edited for length and clarity, we discussed why the field of social epidemiology is crucial to understanding inequality, the causes of racial disparity in health outcomes, and what can be done to ameliorate the suffering of the most vulnerable Americans during this crisis.

Is the spread of the coronavirus, and especially its disproportionate impact on the African-American community, teaching us new things about racial disparities in health care and health outcomes or confirming things we have long known?

More the latter. What the virus is doing is pulling a thread that is showing how many things are actually connected, and how deeply people are actually connected. But it’s also revealing the very different conditions in which we live because of social structures that are inequitable, both within the United States and between countries. By pulling the thread, it’s revealing patterns that have been long known in public health.

So, when you think about something like this coronavirus, you have to think about who’s exposed in the first place and where they are exposed—at work, at home, and what are the conditions? You have to think about, if they’re exposed, do they get infected? You have to think about, if they get infected, do they get ill? And you have to think about, if they’re ill, do they actually die?

And you take each of those steps, which are all different steps in this process, and turn to what are the preliminary—and, I emphasize, preliminary—data on the excessive death rates. My state, Massachusetts, just released the first reports that have any racial or ethnic data. The amount of missing data is horrific. Fifty-three per cent of confirmed cases and deaths have no race or ethnicity recorded. So this is really stunning. Thank goodness for what the journalists are doing compared with what the actual health agencies are doing. And I could trace that back to issues like funding cuts in public health that have been pronounced over the past two decades, if not more.

But what you can do is use this to look at what the coronavirus is exposing. So let’s start with who’s being exposed. Well, if you are living in crowding households—and household crowding is intimately related to lack of living wage and unaffordable housing—what do you have when people are living in crowded spaces? An increased risk of exposure and transmission. If you work in certain kinds of service jobs, which require you to be in close proximity to all kinds of people without sufficient barriers, you’re going to be more likely to be exposed. Who is able to stay at home to do their work and who is not? Who is being given protective gear?

Just think about the amount of work that has been done to organize among, for example, people in grocery stores to make sure that they’re provided with protective gear. They’re considered essential workers now, many of them. Are they essential enough to give protective gear? And then think about the steps that people are being asked to take to protect themselves, including not only physical distancing, while keeping social connections, but also washing your hands. So it’s important to note that there have been calls, for example, for not letting utilities cut people’s water off. In Detroit, that’s been particularly pronounced, because if people don’t have running water how can they wash their hands?

I was just looking at the C.D.C. guidelines on masks, which say that the way to clean masks is with a washer. That is the only thing they listed, and a lot of people don’t even have washers, and certainly not in their homes or apartment units.

I don’t know if you saw the postcard that was sent out to all residents, all people that are domiciled and have a mailing address in the United States, from the Trump Administration about COVID-19. Have you seen that?

I haven’t.

Oh, well, you should’ve got it in your mail. It’s called “The President’s Coronavirus Guidelines for America.” And it says things like, if you feel sick, stay at home—do not go to work. Who can afford to do that? What is this showing about sick leave, and family leave? It says that, if your children are sick, keep them at home and contact your medical provider. Who can watch them at home? Do you have a medical provider? Do you have health insurance? It says that, if someone in your household has tested positive, keep the entire household at home. Again, what are the social conditions that allow people to do that? What are the social policies and what are the glaring gaps that do not allow people to do that equitably in our society? And washing your hands—again, who has access to running water?

So the thing is you can go through each step of what happens with this virus—and we haven’t even got to whether you get ill—and, at each step in this process, you can say, “How is this showing what the threads are that connect us, and who’s not equitably treated?”

It’s interesting that you keep talking about this thread, because I had been thinking that maybe it would be helpful to disaggregate some of these things, even if they have some of the same root causes. So, on the one hand, you have things like people of color being more likely to live in conditions that make preventing exposure difficult. And then you have specific ways in which people of color may not be treated equally once they get sick, or once they’re in a hospital.

Yes. The way that I frame things is what is called the eco-social theory of disease distribution, which asks the question “How do we embody our societal and ecological context?” And the thing about that is that our bodies could give a fig about how people want to parse things out and call this transportation-related, that related to housing, that related to the conditions in the schools, et cetera. Our thinking needs to be integrated, as we are living organisms who are biological and social, constantly interacting with the environs in which we live, which are both biophysical and also social. And it’s never an either/or. It’s always a both/and.

Can you talk about specifically some of the ways in which coronavirus data may be showing people of color being hurt disproportionately?

First, I want to step back and emphasize that the data are really inadequate right now. They are suggestive, but part of the problem is the drastic cuts to public health, and that ties to a framework that somehow one doesn’t need governance and public-health regulations in order to have healthy societies. And I think that this COVID-19 is manifestly showing why that is not the case. In public health, there may have been a lot of attention paid in certain ways to “preparedness,” but it’s also really important that this shows what the gaps are in public-health funding. Public-health workforces are depleted, and that’s part of why we have these extraordinary gaps in data. But it also doesn’t totally make sense, because some of the data that are missing are things that are routinely on death certificates, like race, ethnicity, sex, gender, age, and also education level. But the data are clearly showing racial and ethnic inequities.

From what we know about existing health disparities, what are some of the reasons that, once people of color contract the coronavirus, they are dying of it at higher rates than other groups?

There are two pieces to your question. There’s one piece, which is what’s going on in people’s bodies—the conditions that they have when they present themselves to the health system. And then, given that they get to the health system, what happens to them? So, if a concern is how come they get a lot sicker and are more at risk of dying, some of it may not be about the medical care they receive but because they have so many so-called preëxisting conditions. For example, it’s well documented that cardiovascular disease happens at earlier ages among people who are part of social groups subjected to discrimination and economic deprivation compared with people who are more privileged. It’s the same disease, but it starts earlier. So one of the things that’s happening is that someone who is fifty in a worse-off group can be biologically, in terms of what their health status is, like somebody who’s seventy and in a more privileged group. People are getting infected at a point where there already are massive health inequities in things like diabetes, cardiovascular disease, like respiratory diseases. When you get COVID-19, those make you more likely to have worse mortality.

And what about once you show up in a hospital?

I don’t know right now, because people are on such emergency standing and doing what they can. The question is hospital crowding and hospital resources, as well as the interactions they’re having with hospital staff. So there’s a question of which hospitals now have sufficient ventilators. Separate from the question of what was being worked out and is still being worked out, for example, is who’s going to pay for all this? Who has health insurance that covers it? What’s going to happen with the costs? The tests are allegedly supposed to be covered and not cost anybody, but there was just an article today in my local newspaper, the Boston Globe, about someone being told that they had to pay for their COVID test, a Latinx woman who also didn’t speak English. And that’s a part that matters with some of the treatment issues: To what extent are hospital facilities able to deal with questions of translation?

I think a key point to get across is that there are two different kinds of inequities happening here. One is inequities in health status. The other’s an inequity in health care. And they’re not the same thing—they then collide with each other, and it’s much worse.

Without undermining anything you’re saying about how important it is to stress the interconnectedness of all these things, what are some smaller-scale things that could be done to ameliorate some of the disparities we are seeing with the coronavirus?

There has been a lot of activity among public-health people calling attention to people who are incarcerated and detained, whether it’s for early release or whether it’s about what the standards are for people who are basically in conditions that are not compatible with being safe from COVID-19. There are people who are advocating right now for making sure that there are the income supplements that go to all people. Those efforts are not overturning the entire system. They are about getting remedies right now in a way that the states actually can provide economic relief.

There are public-health actions that are being taken, in terms of doing good education that’s not going to scare people, about how to help keep communities safe and how people can stay safe, and making that available in multiple languages. It’s about helping to make sure that elderly people are being checked on, to make sure that nobody is isolated in their apartments or where they live. There’s work that’s being done imminently and immediately about attending to the needs and health issues of people who are homeless.

And, also, I think another important part where public health has helped is with regard to the fact that people are mandated or advised, depending on which state they live in, to shelter at home, but not everybody’s home is a safe refuge. Homes are also a site of domestic violence and other kinds of abuse. And so there’s been increased attention to what needs to happen with regard to support for domestic-violence hotlines, which have calls increasing. And also the calls to make sure that people who are now deemed essential workers—whether they are undocumented farm workers in California or people like grocery clerks—have sufficient protective equipment.

There was an interesting article in the Times saying, essentially, that you could be more vulnerable to coronavirus if you are in an area with bad air pollution.

My colleagues Francesca Dominici and Rachel Nethery, whom I’m working with, did that study. I’ve done research to show how residential segregation has a link to certain patterns of air pollution. So there’s real neighborhood variation in air pollution, and there’s more and more work that shows that different types of air pollution play a major role in cardiovascular disease, and also potentially birth outcomes. There’s been huge literature on that. And that has to do with what kinds of roads people are living next to and transportation issues. There can be industrial pollution, as well, and that gets back to how different areas are zoned and what that means. There is a lot of literature that makes clear that even something that’s ambient, literally floating around in the air, ends up being socially structured.

I recently came across the concept of “weathering.” Can you explain to people what that is and how it might be manifesting itself here?

Weathering is a metaphor, an idea that was developed by a colleague, Arline Geronimus. And the idea behind that is similar to what I was saying to you before. She construed basically that there’s faster aging among people who are worse off. That would be the simplest way to explain it. This gets back to the idea of the differences between biological age and chronological age, or how people are looking at different kinds of markers of accelerated aging. You can use markers based on epigenetics, for example. There are these things now called epigenetic clocks—you can actually look at places that are getting methylated on the DNA and see that people who are the same chronological age look like they have different epigenetic ages, and those clocks can be related in terms of both how much they correspond to chronological age and also to risk of mortality. So the idea is that just to say that somebody’s fifty is not enough—you don’t know what fifty means unless you know about the context. For example, to be fifty and to be someone who is very privileged is very different than being someone who is fifty and who has been working-class and belongs to a group that’s subjected to racial discrimination. To be fifty in 1940 was still something else in terms of the kinds of health profiles that you could expect to see. So it’s really disabusing people of the idea that there’s this fundamental biology totally distinct from society. What you see, what you interact with, how you live is your phenotype. It’s the way your biology is expressed in societal context.

A lot of people have become familiar recently with what epidemiology is and what an epidemiologist is. But what is the field of social epidemiology, and how would you define what it is you do, separate from anything involving the coronavirus?

Epidemiology is the study of the distribution and determinants of population health, with an eye toward gaining knowledge that can lead to interventions to make things better. That’s a crude answer. It’s not merely a descriptive science, the science that gets into causes—it’s causes with an idea that you’re trying to change that which you are studying. So that makes it very different than if you’re studying the speed of light.

But there are different strands. There is clinical epidemiology, and that’s looking into the impact of health services on health outcomes and can relate to trials of drugs, and it starts wandering off more to the field of medicine. In social epidemiology, you have a focus on what is key to understanding the societal exposures that matter for shaping population health. So social epidemiologists may be involved in doing policy-impact assessments, or health-equity-impact assessments. How does this policy end up affecting, for good or for bad, different groups in society? Others doing social epidemiology are focussed much more on studies that are based on individuals and looking at how their experiences of discrimination may be related to different kinds of biomarkers. But the key point is the fundamental claim that society and the way societies are structured by the people in them, not by random forces, are shaping the patterns of health in that society.

How far back do we have data on things that would be helpful to a social epidemiologist?

Epidemiology as a field earned its name in the seventeen-hundreds, in relation to infectious disease. But, in terms of concerns about the social aspects of health, I can take it back to the Hippocratic texts in 400 B.C.E., in Greece. I can take you back to texts that are even in some of the much earlier Egyptian documents, some of the first papyri about health, that link people’s working conditions to their health. It’s not a huge thing to ask people to observe that, if people are living under worse conditions and working in hard jobs, it’s going to end up harming their health. And that’s in the earliest texts that you find in medical literature.

In terms of social epidemiology as a field and public health, that really got born in the mid-eighteen-hundreds, and it was intimately involved with concerns about differential rates of infectious-disease outbreaks, but also mortality in relation to economic divides. I chair a caucus that I helped found within the American Public Health Association that’s called the Spirit of 1848. And the reason that we chose that name is that it is fundamentally concerned about the links between social justice and public health, and 1848 was when England passed the first public-health act, which was the first time that anyone passed such national legislation setting up public-health boards. This was inspired, in part, by the cholera epidemics. It was fundamentally tied to questions or concerns of poverty, but there were real debates back then. Was poverty the cause of illness, or was immorality the cause of both poverty and illness?

So those kinds of debates are back then and they are now. But the thing is that 1848 was also a period of revolts throughout Europe. People who were working on suffrage, people who were working on abolition, were all making connections between the ways their societies were structured inequitably and what that meant for inequitable health outcomes. These are fundamental themes that are core to public health.


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