By SARA SELIS
The socioeconomic status of the neighborhood you live in may significantly affect your risk of dying over the next year, according to a study by researchers at the Stanford Center for Research in Disease Prevention.
The study found that people who live in neighborhoods with low income or education levels were more than two to four times more likely to die during a given period than those who live in better-educated or wealthier neighborhoods. The results suggest that improving neighborhoods should be a high priority for health-care policymakers.
Published last month in the Journal of Epidemiology and Community Health, the research findings apply to black, white and Mexican-American women and men throughout the United States. The findings are based on sophisticated analyses of data collected from 1987 to 1994 in the federal government’s National Health Interview Survey.
"Our results were remarkably consistent across gender and ethnic groups, which makes the results generalizable to the three largest ethnic groups in the country," said Marilyn Winkleby, PhD, associate professor of medicine at the center and the paper’s senior author. "Clearly, the neighborhood you live in independently affects your mortality."
It has long been known that socioeconomic status has a great influence on health and mortality. But the question of whether neighborhood socioeconomic status has a similar effect on people, apart from their individual status, has gone unexplored except for a few studies which examined limited geographic areas or specific causes of mortality.
Winkleby and her colleague, Catherine Cubbin, PhD, a research associate at Stanford, retrospectively examined 1987-94 data from the National Health Interview Survey conducted by the National Center for Health Statistics. They linked the survey data to mortality information through 1997 and to U.S. Census information corresponding to the neighborhoods where each respondent lived. For all 423,568 people studied, the researchers categorized their socioeconomic status, or SES, based on their education level, family income and employment/occupational status.
The researchers also categorized the neighborhoods where respondents lived, designating them as high-, middle- or low-SES neighborhoods based on their levels of income, education, occupational and employment status and housing values as reported in the census. To analyze the data, the researchers used statistical analyses that took into account both individual and neighborhood-level SES.
The researchers found that socioeconomic status had the strongest influence on mortality. But it was clear that neighborhood SES also influenced mortality above and beyond individual status. The study found that deaths would hypothetically be reduced by about 20 percent for each gender and ethnic subgroup studied if everyone lived in the top third of neighborhoods in terms of socioeconomic status.
The only exception was Mexican-American women, whose mortality risk was not significantly influenced by living in a neighborhood with low socioeconomic status. Winkleby hypothesized that this group’s strong culture, traditions and social support systems may serve to protect Mexican-American women from the unhealthy influences of low-SES neighborhoods.
As for why low-SES neighborhoods may be bad for their residents’ health, Cubbin noted that several factors are likely involved, such as the availability of goods and services. Compared with higher-income neighborhoods, for example, neighborhoods with low socioeconomic status have fewer safe areas for exercise; fewer grocery stores offering affordable, healthy food; and more limited opportunities for good jobs, education and public transportation. In contrast, fast-food restaurants, liquor stores and tobacco advertising are prevalent in such neighborhoods. Lower-income neighborhoods also tend to be closer to pollution sources.
"The reality is that lower-income neighborhoods offer fewer opportunities and present more barriers for a healthy lifestyle," Winkleby said. Given this reality, she said, health-care policymakers and local governments should take action to improve neighborhoods with input from residents. "Improve the bus service so people can easily get to a doctor’s appointment, lobby the fast-food chains to sell healthier food, open up the school gym at night so young people can exercise in a safe environment," she said.
Stanford Report, July 23, 2003