Philippa Clarke, PhD, is a research associate professor in the Institute for Social Research and the Department of Epidemiology at the University of Michigan. Her research interests are in social gerontology, social epidemiology, life course perspectives, disability, and population health. Her current work examines the social determinants of health trajectories over the adult life course; the role of the built environment in disability progression; and the mental health consequences of social policy changes in retirement.
ElderBranch interviewed Dr. Clarke to discuss her recently published study, “Cumulative Exposure to Neighborhood Context-Consequences for Health Transitions Over the Adult Life Course,” which she wrote with Jeffrey Morenoff, Michelle Debbink, and Michael R. Elliott of the University of Michigan, Ezra Golberstein of the University of Minnesota, and Paula M. Lantz of George Washington University.
What led you to research the impact that living, long-term, in disadvantaged neighborhoods can have on an individual’s health?
I’ve always been interested in understanding how our surrounding local environments affect our health. While the study of population health has typically focused on individual risk factors (such as smoking, diet, and alcohol use), the social and physical contexts in which we live (our families, schools, neighborhoods, workplaces) are relatively unexplored areas that can also influence health.
While there has been repeated evidence that residence in a socioeconomically disadvantaged neighborhood may be detrimental to health, there has been really no research that has examined the impact of repeatedly living in a disadvantaged environment over one’s life.
Socioeconomically disadvantaged neighborhoods are typically characterized as having higher levels of poverty, a higher number of residents who are unemployed or on public assistance programs, and a higher proportion of single parent families. Living in these types of neighborhoods can be more stressful for residents even if they themselves are not in poverty because there may be more conflict within or between households, and fewer resources to help one another or to lobby for upkeep or positive changes in the neighborhood.
Why is this important? How does your current research augment other work in this area?
We know that living in disadvantaged neighborhoods is associated with more health problems, such as higher blood pressure, higher cholesterol levels, and more chronic health conditions. But we have not yet considered the effect of repeated exposure to such neighborhoods over a prolonged period of time.
Please describe your study. What were your methods? What were your in-going hypotheses?
We had the opportunity to investigate these research questions using a unique national study of over 3,600 American adults who have been followed over 15 years. This study, The Americans’ Changing Lives Study, surveyed adults age 25 years and over four times since 1986, so we were able to examine the relationship between their residential neighborhoods over time and their health over time.
We also extend the existing literature by explicitly modeling health transitions (are people getting worse, getting better?) in relation to neighborhood context, not just health status, at any given time. We also include transitions to mortality (death) over time.
What were your key findings?
Cumulative exposure to a neighborhood characterized as socioeconomically disadvantaged increases the odds of functional limitations by 20 percent and death by 40 percent over time, even after accounting for an individual’s own economic and social status.
What are the implications of those findings?
Our results suggest that research ignoring a person’s history of exposure to residential context over the life course runs the risk of underestimating the role of neighborhood socioeconomic characteristics for health as people age. When we ran the same models using only current neighborhood context, the effect of living in a disadvantaged neighborhood was much weaker, indicating that you have to consider where people have been living over their whole life in order to appreciate the effects of their residential environment on their health at later ages.
Our results point to the importance of considering residential context when thinking about the social determinants of health, and more specifically, to the importance of considering the long-term context in which individuals have resided over adulthood as it shapes health transitions as people age.
What are the next steps to further your work in this area?
We are continuing to try to understand the importance of our surrounding contexts for health – not only our local neighborhoods, but also the impact of our neighborhoods where we work (or have worked over time).