Dr Audiey Kao: Yeah. So, I'd like to switch gears a little and talk about your methodological work. While we don't have time to get into a graduate seminar discussion about empirical methods you've applied and pioneered in the study of population health, can you provide our audience with a basic understanding of the value and applicability of the Index of Concentration at the Extremes?
Dr Nancy Krieger: Sure. So, the Index of Concentration at the Extremes is actually a measure developed by Douglas Massey, who was one of the leading scholars on residential segregation in this country, and was author among many books of American apartheid, etc. And he used this measure to basically come up with a simple metric that he used only in terms of economics. So, I've extended the use of this measure in ways that I will talk about to address your question.
But basically, what this measure was asking was if you're trying to understand how much is there social-spatial concentrations of extremes and separation, basically polarization? You could look at an area, and you define it geographically or you could define it by an institution. But you have to have something that bounds the population.
Krieger: You could ask how many people are at one extreme, for example, how many people are impoverished. You could ask how many people are at the other extreme, for example, how many people are really wealthy. And then think about what percent of, what's the difference between the two in terms of how much of the population they occupy. So, if the place, if it's 100 percent wealthy, the measure will have a value of 1, if everyone in that area or institution is wealthy. If everybody is impoverished, it will have a value of -1 because it's set up with one group minus the other group divided by the total population.
Krieger: The value of that is that unlike a measure that's just of poverty or just of wealth, which only tells you, doesn't— So, if I tell you that this is an area that these people are poor, 20 percent are poor, you have no idea what it says about the remaining 80 percent. They could all be just near the poverty line, or they could be like really, really affluent. Similarly, if I tell you that an area has 20 percent of people that are really wealthy, it doesn't tell you about who the other 80 percent are. Are they all people that are fairly high income, or are any of them impoverished? So, what this measure does, it allows you to look at the spatial polarization that's social and to see how much people are in one extreme or the other.
What I did was to extend that work, to apply it to not only race in terms of you could look at the proportion that are White, proportion that are Black or Latins or Asian Pacific Islander, whichever groups you want. But also, and this is the innovation, is to make a measure of racialized economic segregation. Because all too often in this country, what happens is people either talk about quote-unquote “race,” or they talk about class. And they have a very hard time putting these two together, let alone with gender, sexuality, or anything else.
Krieger: And so, what the ICE for racialized economic segregation does is it asks you to think about an area in terms of how much of it is concentrated either in White, affluent households or say, in Black, low-income households or low-income households of people of color. And what this does is it keeps both groups literally on the map. And it becomes a very powerful measure to use that tells you more than just poverty and more than just income and more than just racial-ethnic composition. And frankly, there wasn't a measure that was quite like that before.
And the other value of it, which is really important, is that it can be used at many levels of geography. It can be used at the census tract. It can be used at the block group. It can be used at the county and the state. Things like many of the other measures of residential segregation, for example, only get used at the city level because they have to look at how much you move, like the Dissimilarity Index, how much you have to move people around, the different little subunits in the city to get that. But what that means is that you only end up with city-level estimates, which are what's typically used for a lot of the segregation studies.
But what we've shown is that if you include city-level data and census tract-level data, the census tract-level data pack a bigger punch. So, you're underestimating the impact of segregation on health if you're only looking at city-level variables. So, there's a lot there.
But the point is, is that the value of this particular measure is it makes you think about groups in relationship to each other. Just as in the case, you can't have rich without poor. [chuckles] You can't have White with Black. You can't have men without women, let alone non-binary. Groups are codefined in relationship to each other. They're not essential things unto themselves.
Krieger: That's what this measure helps keep in the forefront.
Kao: So, as you just alluded, these and other measures are ways that, for example, local public health agencies can use to surveil and monitor population health disparities in their jurisdictions.
Kao: That said, most state and local public health agencies are inadequately funded. One example is the more than 20-year moratorium on federal funding into gun violence. And according to a 2017 study, the number of publications about gun violence declined 64 percent from 1998 to 2012. And while that number of publications picked up through 2014, it's estimated that there are no more than 20 full-time gun violence researchers in this country. While Congress recently approved $25 million for gun violence research, public health funding remains woefully inadequate.
So, while scientific research is not generally seen or considered to be political advocacy, how should public health researchers and practitioners go about advocating for needed funding to support public health research and infrastructure?
Krieger: So, again, you have a lot packed into that question. And I think first, it's really important to say that scientific research is not by itself advocacy. People advocate. And when you do research, you always have to think about the strengths and limitations. You frame your hypotheses. You test them. You don't just get to assert opinions. And you certainly do not get to cherry pick the evidence. And I certainly have published studies, for example, which didn't have the findings that I expected, which leads to lots of introspection. You always have to rule out error because error can always happen. And so, did you make a mistake, which would be really bad, [chuckles] or is there a new finding here that something happened that is different than what you expected? So, those are the kinds of views.
And it's really important that if you want your science to be used for advocacy, it had best be as rigorous as it can be.
Krieger: Because no one is helped by good science, and certainly no one is helped by ignoring or denying science. That's even worse. So, I want to be really clear that the science really means that you're doing public, transparent research—transparent about the ideas, the data, the methods—and that anyone can test it. These are not personal, private opinions. It's meant to be testable knowledge. That's where the replication comes in. That's so important. And if things work here and don't work, is it because, again, there's an error or because there's something really different that's really important to understand? There's a lot on transportability in terms of understanding that.
That said, you can ask your questions based on things that you think that would be useful to know about the world: to know about what might affect rates of violence, to know about what might affect rates of suicide to know what might affect these things. Because they are questions that come from the world. People want to know the answers, and you might be one of those people as well. And how do you answer those questions as rigorously as possible?
Krieger: So, you do need funding for that because, again, data don't fall out of the sky. Somebody has to pay for it. I mean, people think they grab stuff off the Internet, but that comes from somewhere. Somehow those data have been tabulated, collected, gathered, interpreted, and combined.
So, what it means is that public health in general has been incredibly underfunded. I mean, it's never recovered from the 2008 economic recovery. It's not been valued. We see the impact of that in what's happening with the response to the COVID pandemic. Separate from any of the politics of that, just the flat out lack of capacity is really, really worrisome. So, yes, there's a lot that needs to happen. And it's not only in relation to gun violence.
I think the last point to bring out is that there's a time disgraced tradition of basically trying to have no data, no problem. And what that is, is that when people in power do not want there to be, and something is contributing to their power but is causing other people harm, they generally try to suppress it. This has a very long history behind it. And it's why you see the incredible assaults right now on, for example, environmental and public health regulations and protection. Because when you show harm, and particularly when you show embodied harm in people, it opens you up to liability and accountability.
And so, if you think about the cue and cry right now, for example, about the lack of racial-ethnic data, let alone socioeconomic data, which hardly anyone's still talking about with regard to COVID-19, this is part of a pattern. It's not surprising. It's wrong. But what you need to understand is data are powerful. And again, not to cherry pick the data and to spin a story. That is, if you're doing the science, that's not what you do. If you're doing the advocacy work, you may selectively emphasize parts of the story or not. But that's not the science. That's a different part of very practical, absolutely necessary work to make things better for the people's health.
Kao: Yeah, no. I think, again, you make some powerful points. If I can just loop back to something you said earlier in our conversation. You mentioned that nobody disputes that health care policy is health policy. But frankly, educational policy is also health policy. Tax policy is health policy. Criminal justice policy is health policy. How should clinical medicine and public health better work together to advance the well-being of individuals and populations, given this larger lens that I just described?
Krieger: So, one thing I think is really important is to be careful about having health be the ultimate arbiter, while at the same time knowing that health really matters. So, there's lots about education that may have nothing to do with health. And then there are things that really do have to do with health. There are things about transportation that don't have to do with health, and then they do have to do with health. Is there a conversation going on similarly with housing, whereby the different disciplinary insights and the different insights of the fields can come together in a way that's synergistic, where each benefits from the other, where we in public health can bring in, for example, that sense of what different things mean for people's health while also learning about the parts that we may not even be aware of in terms of what some of the policy issues are or the resource issues are.
So, to me, it's a two-way engagement. It's not that it should all become health policy because they have their real job to do. And it comes up a lot. I, as a public health person, I can help document what some of the problems are, and I can help document whether changes in policies make a difference for health.
But for example, on the questions right now that are best related to what are the different methods that people are seeking in their reform, for example, of policing, what you can do is you can show something seemed to have had no effect at all, like body cams and what happens, and others begin to maybe have effects. So, it's really important to bring those together. But to have a frame of health in all policies and health equity in all policies is useful in terms of reminding everyone that everything ultimately will be affecting health. The question is how. And what is salubrious and is promoting of health equity matters to think about, too, as well as what is injuring health.
And I think also what's interesting is that because you also have to think about people being the ones that are responding. You know, there's been interesting discussions among people that are working on climate crisis and climate justice that bringing in the human health dimensions has caught the attention of some groups that otherwise would not have paid attention. Now, is it right to have everything be so anthropocentric? No, because we're just one species among many on this planet, and there's many that have lived on this planet way longer than ever before Homo sapiens even showed up on the scene. However, we've changed the terms of life for all. So, no, it's not good to be purely anthropocentric in thinking. On the other hand, from a policy standpoint, people really do pay attention when you start.
And it's not just that; it's that people also have—although this isn't entirely beginning to change—they have the capacity to sue, and they have the capacity to plead things in court. I mean, yes, there is a river now in New Zealand that has rights for legal standing in court. But this is the exception, not the rule right now. So, I think one needs to think about it in those ways as well. Who has a claim that can make good on that around injury that makes a difference in litigation and policy?
Krieger: And health is crucial in all of that.
Kao: Yeah. No, I appreciate your points. So, as we near the end of our conversation, you've already alluded to much of your work and how it relates to the current public health threat. But I'd like to get your final thoughts about how your work can help all of us better think about and approach the current pandemic and its disproportionate impact on those among us who not so long ago were not considered quote-unquote “essential” in our society.
Krieger: Well, that's again, it's like the same statement I alluded to earlier about the framing of saying slavery is a necessary evil. Necessary for whom? So, this essential is, people have been essential all along, whether they have been valued by those who pay them. That's another question entirely. And what this pandemic has shown is that people who are essential workers, which is actually the bulk of people who work in the United States, by the way, I mean, it's a small percent that are able to stay at home and do their work. And that's enabled in part by the technologies now of who can do work on the computer, for example, only, as opposed to physically moving about in time and space and manipulating objects.
And so, what happens is that what the pandemic has exposed is, it's in effect pulling the thread on inequities that've been long known, but it just ties them all together. Because again, we embody it all. Our bodies don't decide that this is a housing problem one day; this is a transportation problem another day. This is a workplace problem still another day. Because we live it all simultaneously. We're always integrating. That's the theme of embodiment.
So, what this is pandemic has shown is a, whose work is truly essential in that kind of way, b, that exposure matters. I mean, I think one of the things in terms of understanding the gross racial-ethnic inequities, we're just about, we have a new working paper out that's showing, for example, that the age-specific mortality rates are way higher in working-age adults for Black and Latinx and American Indian against the White non-Hispanic population. Whereas if you look at just the -standardized rate, which is weighted towards older populations, you don't see the extremes quite as much. You still see the, but not as much.
Krieger: People have to be exposed. And so, what this means is orient to how do you stop people from being exposed? Well, where are they being exposed? Well, the primary places people are being exposed is at work, is potentially going to and from work. It depends on the modes of transportation and what's available. And then there's also the question of who's living in crowded housing. And crowded housing is a function of lack of living wage and lack of affordable housing.
And so, I mean, we've done the work both at all counties in the U.S., but also looking among the first to do that and to point to the importance of the crowded housing. And crowded really means crowded. And when you look at U.S. Census data, crowded means more than one person per room, basically not counting the bathroom. So, if you have an apartment that has one bedroom, one kitchen, and one living room or dining room, that's three rooms. That would only be considered crowded if four or more people were living there.
Krieger: Which is crowded.
Krieger: So, it's really important to say that what our work is showing is what those things are. And it takes away some of the emphasis from people saying, “Well, no, it's because people have pre-existing chronic conditions.” Well, those pre-existing conditions are pre-existing inequities. There is so much work on why there are differential rates of chronic diseases, particularly cardiovascular, diabetes, cardiometabolic, etc., that are happening among people who live in areas and are parts of communities that have been underserved and underinvested and subjected to different kinds of discrimination, particularly racial. And so, that's given, but it can't explain.
Because we're seeing mortality rate ratios, for example, in the younger ages that are seven to nine times higher. And the highest you would get from racial-ethnic differences in, for example, diabetes mortality or heart disease mortality is going to be around two to three, and those are really big. And we're seeing things way higher. So, there's no way it's going to be explained just by pre-existing conditions, so-called. So, what I think the work is pointing to, it raises the question, what's going on around prevention?
It's really telling that in this time, particularly because of the undermining of not only public health, but within that, OSHA, under this particular administration, there's been only one citation. We're analyzing a database that OSHA has put up closed and open complaints that has 14,000 complaints, citations.
Krieger: So, I think it's really important to be asking those questions about the conditions of work, the policies at work. And the policies are about the physical biophysical conditions at work, how close people are, what the physical processes are they're doing. But they're also about the social policies. Who has sick leave?
Krieger: How is that enforced, etc., etc.? So, I think that the kind of work that I'm doing helps bring all of that to light in ways that is useful to push about what kinds of data are needed, particularly for local areas, to understand what's going on with the pandemic and what that means, again, for prevention.
Kao: Yeah. Well, I wish we had more time, but unfortunately, we don't. I want to thank Dr Krieger for sharing her deep expertise and insights with our audience today. Dr Krieger, thank you for being a guest on Ethics Talk.
Krieger: Thank you very much for having me.
Kao: For more COVID ethics resources, please visit the AMA Journal of Ethics at JournalOfEthics.org. And to our viewing audience out there, the Latin root for the word “conscience” means “with knowledge.” I encourage everyone to do the right thing and act and advocate in accordance with the best of the available public health evidence because lives and livelihoods during and after this pandemic depend on it. Be safe and be well. We'll see you next time on Ethics Talk. [bright theme music plays]
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