STANFORD, Calif. - By living in a well-to-do neighborhood, poor people increase their risk of death, according to a new study by Stanford University School of Medicine researchers to be published in the December issue of the American Journal of Public Health.
"We tend to assume that people living in a high socioeconomic status neighborhood are well off," said Marilyn Winkleby, PhD, associate professor of medicine at the Stanford Prevention Research Center and lead author of the study.
Instead researchers found that death rates were highest among people of low socioeconomic status who also lived in affluent neighborhoods. That finding surprised the researchers, but "every way we looked at the data, we found the same result," said co-author Catherine Cubbin, PhD, a former research associate at Stanford who is now a researcher at UC-San Francisco and University of Texas-Austin. The researchers said the findings also indicate that this particular group of people might be medically underserved and need more targeted services and attention by health policy makers.
Previous studies had shown that neighborhood plays an important role in an individual's health. Most studies have found that people fare better in high-income neighborhoods. The Stanford study is unique because it combined individual economic status with neighborhood status to gain a more refined look at the issue.
The researchers discovered the trend by analyzing data from another study that looked at the incidence of heart disease risk factors in California between 1979 and 1990. The study followed 8,200 men and women from 82 neighborhoods in Monterey, Modesto, Salinas and San Luis Obispo over 17 years.
The researchers used income and education to determine individual socioeconomic status. They then divided people into low, moderate or high socioeconomic groups. Similarly, the researchers classified neighborhoods as being of low, moderate or high socioeconomic status.
The study found that over time, the differences in death rate between the groups became more pronounced. After 17 years, 19 out of every 1,000 women of low socioeconomic status who lived in wealthier neighborhoods had died, compared with 11 of every 1,000 from poorer neighborhoods. The trend was similar, but less dramatic in men.
They found that age as well as a number of risk factors, such as obesity, hypertension and smoking, did not account for their results. There were also no differences in the causes of death, which were largely due to chronic diseases, the researchers said. They also found that access to neighborhood goods and services, such as health care, grocery stores, parks and gyms, did not explain their findings.
Winkleby suggested two explanations for the discrepancy. The first is purely economic, as the cost of living in an affluent neighborhood could leave poor people with little disposable income to spend on essential goods and services, such as health care and healthy food, and less time to take advantage of the benefits of living in a high-income neighborhood.
"Economically this group may be worse off," said Winkleby. Access to free social services and health care could also be a factor because these services are often concentrated in low-income neighborhoods, she said.
Another possibility is that poorer people in higher-income neighborhoods fare worse for psychological and social reasons.
A discrepancy in a person's social position relative to others may have an effect on a person's health, said Winkleby. "You look out every day and you're at the bottom of the social ladder," she added.
The researchers caution that their study does not mean poor people are necessarily better off living in low-income neighborhoods. "There could be other benefits" to living in a wealthier neighborhood, said Cubbin. "We don't want to imply that poor people should move to poor neighborhoods, where there continues to be great need."
Moreover, the study highlights the needs of a population that may be overlooked and underserved by government agencies and health workers.
"There's a group of people really at risk that we're not even thinking about," said Cubbin.
Winkleby and Cubbin's co-author was researcher David Ahn, PhD, also at the Stanford Prevention Research Center. The work was funded by a grant from the National Institutes of Health.
Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at http://mednews.stanford.edu.
Journal
American Journal of Public Health