New data suggest that neighborhood environments have significant effects on health.
A person’s level of neighborhood deprivation had an effect of their risk for type 2 diabetes, a new study has found. A quasi-experimental study looking at refugees in Sweden dispersed to low-, moderate-, or high-deprivation neighborhoods showed that assignment to a high-deprivation area resulted in a significantly increased risk for diabetes.
“This effect accumulates over time,” researcher Justin S. White, PhD, of University of California, San Francisco, told Medical Economics. “Our study speaks to the importance of neighborhood environment on risk of diabetes and other chronic diseases. It suggests that investing more in more vulnerable communities could lead to meaningful improvements in health.”
The results of the study were published online in Lancet Diabetes & Endocrinology
According to the study, prior research has shown that neighborhoods where people live are correlated with diabetes risk. However, correlation is not causation, White pointed out. With this analysis, White and colleagues wanted to build on observational studies to test whether neighborhoods exert a causal effect on diabetes risk.
To do that, they used a unique natural experiment in which the Swedish government dispersed refugees, more or less at random, to neighborhoods throughout Sweden, allowing them to compare outcomes among refugees who ended up in a low-income area with those in a high-income area.
The study included data for 61,386 refugees who arrived in Sweden from 1987 to 1991 and were assigned to one of 4,833 neighborhoods. About 90% of refugees were initially assigned to a moderate- or high-deprivation area.
Using an adjusted logistic regression model, the researchers found that assignment to a moderate-deprivation area increased the odds of type 2 diabetes by 15% (odds ratio [OR]=1.15; 95% CI, 1.01-1.31) and assignment to a high deprivation-area by 22% (OR=1.22; 95% CI, 1.07-1.38; P=.001), compared with a low-deprivation area.
Further analysis showed that the refugees’ risk for diabetes accumulated over time rather than occurring immediately. Specifically, five years of additional exposure to a high-deprivation area resulted in a 9% increased risk for diabetes compared with a low-deprivation area.
According to White, this study cannot determine whether these findings apply to other non-refugee populations, although the researchers suspect that they do.
“If anything, our findings probably understate the more general effects that neighborhoods have on diabetes risk, because refugees in our study were allowed to move after the initial placement,” White said. “By moving to a better area, they could undo some of the effects of neighborhood deprivation that we estimate.”
White said that the results of this study should contribute to several ongoing conversations in society today.
“In part, it speaks to the ongoing refugee crisis in Europe, and suggests that investing in support for this vulnerable group early on may have beneficial effects for refugees and for society decades later,” White said. “It also speaks to a broader conversation about inequality, and suggests that the deprived areas in which people live may have huge implications for their health beyond simply their own individual characteristics.”