Dr. Mitchell S. V. Elkind, MD, MS, FAAN, FAHA, is a Professor of Neurology and Epidemiology at Columbia University Irving Medical Center. He is the Head of the Division of Neurology Clinical Outcomes Research and Population Sciences (NeuroCORPS). Presently, he serves as the president of the American Heart Association.
He is interviewed by Dr. Melanie R. F. Greenway, MD, vascular neurology fellow at Mayo Clinic in Jacksonville, Florida.
They will be discussing the paper “Approaches to Studying Determinants of Racial-Ethnic Disparities in Stroke and Its Sequelae,” published in the November 2020 issue of Stroke. The article is part of a Focused Updates series of articles on topics related to health equity.
Dr. Greenway: To start, I would like to thank you for writing this comprehensive review on studying race-ethnic disparities in stroke as part of this unique series of articles in Stroke on health equity. This review provides an important framework for anyone embarking on their own epidemiologic research, as well as those of us reading and interpreting the race-ethnic disparities literature that is rapidly evolving. To start, you describe health disparities between groups as “a difference with a difference.” Can you explain what you mean by this?
Dr. Elkind: Disparities refer to differences in health that result from a very specific set of reasons, such as social, economic, or environmental disadvantage. There are many reasons why people may have different health outcomes, but when we talk about disparities, we are referring to differences that are often due to being part of a particular race or ethnic group, or to being part of another group that has historically experienced disadvantage.
Dr. Greenway: When describing the study of race-ethnic disparities, you describe multiple large observational cohort studies and comment that in some, “it becomes impossible to disentangle the effects of race/ethnicity from place.” In your opinion, how much of an impact is location on the generalizability of race-ethnic disparities?
Dr. Elkind: Location is important. We know, for example, that certain parts of the U.S. have much higher stroke incidence and mortality, like the Stroke Belt in the Southeast. This is why it is important to understand whether the race-ethnic differences that we see in the Southeast are also true of other parts of the country. And it appears that they are. In Northern Manhattan, for example, Black people have twice the risk of stroke as White people, and Hispanic people are also at increased risk. Importantly, though, there are other factors besides race and ethnicity that could account for some of these differences: The rural-urban divide could be as important as the race divide, with some rural areas having higher rates of stroke. It is important to account for many potential confounders, not just race or place, when assessing risk.
Dr. Greenway: As a follow up, given the cultural, socioeconomic, and geographic diversity of the United States, I have wondered if we should evaluate race-ethnic disparities at more of a local/regional level rather than generalizing the United States as a whole. Do you find the results of large multi-regional cohort studies dilute the disparities seen within a particular community?
Dr. Elkind: I agree that it is important to try to understand disparities across many different communities, and to explore the specific reasons for these disparities in distinct populations. Epidemiology and the study of disparities require understanding many communities to get a coherent picture or pattern. So many interconnecting factors play a role that we need to examine these issues at many levels, while also trying to understand the big picture. People often talk about focusing on the forest and the trees. But both have important roles to play.
Dr. Greenway: When evaluating patient registries and administrative datasets, we often hear the expression “garbage in, garbage out,” which can be discouraging for young investigators interested in this type of work. What advice do you have for people interested in studying these large datasets, given the limitations of missing data and potential misclassification?
Dr. Elkind: The way I think about it, all data sources have their potential advantages and disadvantages. Large administrative databases can be most valuable for identifying questions for further study or obtaining preliminary data to justify grants. They should not be considered final. But, then, no single data source will be final. In this kind of research, confirmation and validation in other datasets are essential. The goal is really to build a coherent story out of all the data available.
Dr. Greenway: You mention the use of animal models, such as mice, to investigate the biological basis of effects like social isolation on stroke outcome. I was previously unfamiliar with this research and found it very interesting. What types of social determinants of health would you like to see modeled in animals, and how do you think this information could be used to decrease health disparities among groups within our communities?
Dr. Elkind: Animal research can be used to model types of behavior that may be found in humans, as well. Social animals can be used to study the impact of adverse or beneficial social experiences on cardiovascular and brain health. Time spent with others, nurturing behavior, social networks, fear or helplessness — all these may be amenable to study. These kinds of studies can provide insights and even mechanistic directions for how to approach these issues in human beings, as well.
Dr. Greenway: One interesting problem with research of race-ethnic disparities that you mention is the ability to accurately reflect burden of disease because of the potential difficulty collecting accurate data regarding number of cases and size of the population. What interventions would you recommend increasing data collection from these under-represented groups?
Dr. Elkind: We should be directing resources to collecting this information about the health status of all people in the U.S., and globally. I am hopeful that with innovations in quality and increased access to healthcare through insurance reform, we will be able to collect this information. We should also be encouraging people to participate in clinical trials to increase the representativeness of those trials. One side effect of the pandemic may be that people have learned a bit more about the importance of medical research in addressing a crisis; I hope this enthusiasm for medical research and evidence carries over after the immediate crisis passes.
Dr. Greenway: As an expert in the field of neurology and epidemiology, how did you become interested in race-ethnic disparities, and what drives you to continue this research?
Dr. Elkind: I practice and teach in New York City, which is one of the most diverse cities in the world. We are constantly exposed to people with very different cultures and backgrounds, and we also see the effects of social and economic disadvantage on stroke and other health outcomes. Often the medicines and medical interventions I rely on are less important to people’s outcomes than people’s health literacy and economic resources. Practicing here, my colleagues and I have come to realize how important health disparities are.
Dr. Greenway: Lastly, you connect the need for investment in race-ethnic disparities research to the current global COVID-19 pandemic. As we continue to learn about COVID-19 and its long-term biological and societal implications, how should we consider race-ethnic disparities in our day-to-day practice?
Dr. Elkind: It is important as practitioners, taking care of individual patients, to remember that we need to consider how well our treatments will work in the context of people’s lives. It doesn’t help to prescribe expensive drugs tested in fancy clinical trials if our patients can’t afford to buy them. Air pollution is a stroke risk factor, so we may not be helping people if they return home to crowded living areas with poor air quality. We need to advocate for access to care and for better and safer living conditions for all people, regardless of their means.
Dr. Greenway: Thank you for your time, and thank you again for writing this review on race-ethnic disparities in stroke.