Johnny and Sally both attend the same private high school in Chicago. But when the final bell rings, Johnny goes home to the predominantly African-American East Garfield Park community on the west side of the city. Sally usually takes the train back home to Lincoln Park, a predominantly white area on the north side of town.

Both sets of parents make the same total household income and agree that they give their kids the same opportunities in life. But while they’re seemingly awarded the same opportunities, the reality is that one of these fictitious characters is expected to die 12 years earlier than the other, simply because of where he lives.

A recent study shows that the differences in neighborhood conditions strongly predict who will be healthy, who will be sick, and who will live longer, independent of income. The Washington, D.C.-based Joint Center for Political and Economic Study released Thursday a report that examines how social and economic conditions in Cook County are linked to poor health outcomes.

The report, “Place Matters for Health in Cook County:  Ensuring Opportunities for Good Health for All,” is part of a series of reports supported by a grant from the National Institute on Minority Health and Health Disparities of the National Institutes of Health.

The study provides a comprehensive analysis of the range of social, economic, and environmental conditions in Cook County — particularly as they relate to the quality and accessibility of healthy foods — and documents their relationship to the health status of the city’s residents, according to The Joint Center.

The study is “based mostly on the fact that the city of Chicago is still hyper-segregated,” said Dr. Linda Rae Murray, immediate past president of the American Public Health Association and chief medical officer of the Cook County Department of Public Health.

Chicago and its nearby surrounding towns are known as one of the nation’s most segregated metropolitan areas. “It’s not surprising that we find that pattern,” said Murray.

“Because of patterns of residential segregation, these differences are the fundamental causes of health inequities among different racial, ethnic, and socioeconomic groups,” said Ralph B. Everett, president and CEO of the Joint Center for Political and Economic Studies, in a statement.

In Cook County, 75 percent of all black children live in communities where over 90 percent of the population is poor, Murray said, while 85 percent of white children live in communities where less than 10 percent of the population is poor. Poorer communities have less access to healthy food stores and other resources.

“What seems like a minor issue — lack of a grocery store — can impact people’s health in such a drastic way [and] affect life expectancy,” said Murray.

“Segregation… leads to patterns of disinvestment in low-income communities and matters in other communities that affect health,” said Brian Smedley, PhD, vice president and director of the Joint Center Health Policy Institute.

According to Dr. Daniel Block, a Chicago State University geography professor and food access mapping specialist, the maps don’t lie.

“You can pretty much predict the distance to the nearest store… by where the major African American areas are in the city. We can’t say that necessarily one causes the other, but the correlation is amazing,” Block said.

The study also conducted qualitative research and interviews.