The historically discriminatory housing policy known as “redlining” is now linked to heart disease and related risk factors in affected neighborhoods, more than 60 years after it was banned, according to a study published today in the Journal of the American College of Cardiology. Health inequalities have been linked to a variety of socioeconomic, environmental, and social factors, and this study adds to the growing evidence of the long-term cardiovascular impact that inequalities can have on vulnerable populations.
“Redlining” is a term used to describe a variety of discriminatory housing practices. Its origins date back to a 1930s government program created during the Great Depression when the Home Owners’ Loan Corporation created maps of nearly 200 US cities with ratings based on racial/ethnic makeup, housing conditions, and neighborhood environments. Scored areas were color-coded based on potential credit risk as A (“best” or green), B (“still desirable” or blue), C (“definitely declining” or yellow), and D (“dangerous” or red). . . The D-rated neighborhoods were considered as “redlined” neighborhoods. These housing practices were banned in the 1960s, but their impact and other discriminatory practices have continued to shape contemporary social and environmental structures over the past century, leading to widening health inequalities.
“We already know that historical redlining has been linked to modern health inequalities in large urban areas, including asthma, certain cancers, preterm birth, mental health and other chronic diseases,” said Sadeer Al-Kindi, MD, a cardiologist at University Hospitals Harrington Heart & Vascular Institute and Assistant Professor of Medicine at Case Western Reserve University in Cleveland and senior author of the study. “Although our study is the first to examine the national relationship between marked neighborhoods and cardiovascular disease, it is logical that many of the socioeconomic, environmental, and social impacts of marking on other areas of residents’ health also apply to heart disease.” can be seen.”
A previous study showed that black adults living in historically marked areas had lower cardiovascular health scores than black adults living in A-rated neighborhoods. The current study supports this finding and expands on the proven health inequalities at the national level by showing that redlining not only affects coronary artery disease, stroke and chronic kidney disease, but is also associated with an increased risk of comorbidities and lack of access to appropriate medical care is.
The researchers used original tiered data from the Home Owners’ Loan Corporation (HOLC) and calculated the percentage of overlap between the tiered neighborhood boundaries and the 2020 U.S. census tract boundaries. They excluded all census tracts with less than 20% total intersection area. Researchers used the graded intersection points to create a scale with their corresponding numerical HOLC scores (1-4 corresponds to AD) and created a score that was transformed back into one of four categories: A(1), B(2 ), C (3) and D (4). The study defined redlined neighborhoods as D-rated census tracts and unreduced neighborhoods as A- through C-rated census tracts.
The CDC PLACES database, which contains census tract-level prevalence estimates of health indicators and census tract-level exposure to particulate matter and diesel particulate matter from the Environmental Protection Agency’s 2021 Environmental Justice Tool, was used to calculate potential environmental confounders. Other outcome variables and scores used were: markers of health care access, cardiometabolic risk factors, and cardiometabolic outcomes. Researchers then linked HOLC-assessed census districts to the prevalence of cardiometabolic indicators and averaged each indicator across census districts at each HOLC grade.
More than 11,000 HOLC-assessed census tracts with over 38.5 million residents were included. The A-rated areas covered 7.1%, the B-rated areas 19.4%, the C-rated areas 42%, and the D-rated areas 31.5% of the census tracts. The percentage of Black and Hispanic residents increased across HOLC grades (AD for each). Across HOLC grades A through D, the researchers found statistically significant increases in the prevalence of coronary artery disease, stroke, and chronic kidney disease.
“We found that neighborhoods with so-called better HOLC scores had higher levels of cholesterol screening and routine health visits compared to neighborhoods with poorer HOLC scores. And the prevalence of adults ages 18 to 64 without health insurance has nearly doubled from A to D,” said Issam Motairek, MD, lead author of the study and clinical research associate at the Harrington Heart & Vascular Institute at University Hospitals in Cleveland. “With each incremental increase across the HOLC grading spectrum from A to D, we also observed an overall increase in rates of diabetes, obesity, hypertension, and smoking.”
According to the researchers, the association between redlining and the prevalence of cardiometabolic disease further illustrates that historical redlining practices can influence contemporary cardiovascular outcomes through traditional and non-traditional risk factors. Residents of red-line neighborhoods, particularly minorities, are known to have less access to public transportation, health insurance and healthy food, increasing their risk of missed prevention and negative health impacts.
Differences in environmental exposure and socioeconomic characteristics may help explain poor health outcomes in red-boxed neighborhoods, which are often located adjacent to major sources of pollution, and make residents more likely to experience the adverse health effects of disproportionately higher exposure to air pollution and less Environment experienced outer space and other environmental toxins. Residents of neighborhoods highlighted in red also experience financial strains, broken communities, and racial discrimination, all of which can lead to increased stress and associated adverse health effects.
Study limitations include self-reported health outcomes in the CDC PLACES database that may be mischaracterized. The study was also unable to measure confounders such as behavioral and genetic factors. The definition of redlining census district boundaries was also not standardized across studies.
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