Does where you live affect your health?
Research has shown that neighborhoods with high socioeconomic deprivation also have higher mortality rates. But, those studies were a snapshot in time and did not consider how changes in socioeconomic deprivation — either positive or negative — corresponded to changes in health.
Most research also didn’t track subjects over time to determine if health outcomes improved when a person’s neighborhood conditions improved.
In a pair of new observational studies published in August and November in the journals American Journal of Epidemiology and Cancer, Dr. Qian Xiao, assistant professor of health and human physiology with a secondary appointment in the department of epidemiology, tracked health outcomes among Americans who stayed in the same neighborhood for more than a decade. For the American Journal of Epidemiology, Dr. Xiao examined mortality rates for cardiovascular disease, cancer, and all causes generally. For Cancer, Dr. Xiao and postdoctoral researcher Dr. Dong Zhang studied rates of colorectal cancer specifically.
[Photo: Dr. Qian Xiao]
“The reason why we thought our study design is important was that previous studies only looked at conditions at one time point,” Dr. Xiao says. “People in lower socioeconomic status neighborhoods are more likely to die and more likely to get cancer. The next step would be, if you changed your neighborhood, would that have an impact on your health outcomes? That’s really the focus.”
Dr. Xiao says the studies supported her hypotheses — if the socioeconomic status of a neighborhood improves, mortality rates decline; however, if the status deteriorates, mortality rates rise. To measure socioeconomic status, Dr. Xiao says she looked at variables within neighborhoods such as household income, the number of people living beneath the poverty line, employment rate, and education levels, among other factors.
“If you improve neighborhood conditions — if a neighborhood is in an upward trajectory — we found that there is a lower mortality rate,” she says. “If a neighborhood has a downward trajectory, the death rate rises.”