Discriminatory redlining practices may affect current asthma ED visits
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Present-day asthma-related ED visits are more than twice as high in California neighborhoods that were deprioritized for mortgage investments, or redlined, in the 1930s when compared with areas that were deemed less risky for investments, according to a study published in The Lancet Planetary Health.
During the Great Depression, the Home Owners’ Loan Corporation (HOLC), which was formed as a measure to refinance defaulted home mortgages, used neighborhood redlining as a way of assessing the risk of applicants who applied for refinancing on mortgages on which they had defaulted, the researchers noted. Neighborhoods were divided into one of four grades of perceived risk. Often, according to the researchers, inner-city areas with predominantly black and immigrant populations were redlined, meaning that they were categorized as hazardous for investment.
To determine whether the racial and ethnic disparities in asthma burden may be related to these types of practices, the researchers evaluated the link between residential redlining and current asthma-related ED visits in California.
Increased ED visits in redlined areas
The researchers used HOLC security maps for Fresno, Los Angeles, Oakland, Sacramento, San Diego, San Jose, San Francisco and Stockton. Neighborhoods had been categorized as A, B, C and D for risk assessment, with lowest-risk areas receiving an A grade and highest-risk, or redlined, areas receiving a D grade. The researchers then evaluated the association between risk grades and asthma-related ED rates from 2011 to 2013.
Of 1,431 census tracts assigned a HOLC risk grade, 4.5% were grade A, 16.8% were grade B, 50.2% were grade C and 28.4% were grade D. Results showed that the median age-adjusted rate of ED visits due to asthma was 2.4 times higher in D-rated tracts than in A-rated tracts (63.5 vs. 26.5 visits per 10,000 residents per year) and 1.7 times higher than in B-rated tracts (37.9 visits per 10,000 residents per year). Moreover, in adjusted analyses, the estimated risk for asthma-related ED visits was 39% higher in redlined areas, as compared with A-rated areas, and historical redlining was associated with an age-adjusted 15.6 additional asthma-related ED visits per 10,000 residents annually.
The researchers also noted significant trends in demographics, poverty rate and exposure to air pollution with worsening HOLC risk grades. For instance, more than two-thirds of residents in A-rated tracts were white as compared with less than 20% in D-rated tracts. Additionally, in D-rated vs. A-rated tracts, estimated diesel exhaust particle emissions were twice as high and the poverty rate was more than three times as high, with more than half of residents living at two times below the federal poverty level in redlined areas.
Ramifications of redlining
In speculating about reasons for the increased asthma-related ED visits in areas with higher HOLC risk grades, the researchers cited potential long-term effects related to redlining.
“Redlining may have shaped neighborhood development in ways that compound risk factors for asthma,” Neeta Thakur, MD, from the department of medicine at the University of California, San Francisco, said in a press release. “For example, highways constructed in the 1940s and ’50s were commonly constructed in poorer neighborhoods worsening the air quality. Redlined neighborhoods had high rates of low socioeconomic status, which are associated with decreased access to health service and increased psychosocial stress, both contributors to asthma incidence, prevalence and severity.”
A lack of opportunity in these areas may also be a factor, according to Anthony Nardone, MS, from the UC Berkeley-UCSF Joint Medical Program.
“Americans living in redlined neighborhoods who were denied financing likely missed out on home ownership opportunities, reducing their potential to generate wealth over generations and leading to further segregation of neighborhoods,” Nardone said in the release. “This inability to accumulate wealth along with entrenched segregation could ultimately affect asthma risk, particularly for communities of color, by reducing quality housing options and ability to buffer stress.”
However, the researchers noted that the study was not without limitations. For example, the use of asthma-related ED visits as an outcome was designed to identify areas most burdened by asthma, but health care access, insurance coverage and baseline asthma prevalence may be different in redlined neighborhoods, meaning that the study findings may have over- or underestimated the true association.
Overall, though, the data raise concerns about how discriminatory practices such as redlining may affect health decades later, according to John R. Balmes, MD, from the department of medicine and the division of pulmonary and critical care medicine at the UC Berkeley-UCSF Joint Medical Program.
“Eighty years or more after the development of the security maps, we observed persistently higher asthma-related ED visits in redlined neighborhoods compared with higher-graded neighborhoods. These areas also see higher diesel particle emission levels and rates of poverty. Together, these might partly reflect a discriminatory legacy of redlining. Similar research is needed to assess whether our findings apply beyond the eight Californian cities we studied,” Balmes said in the release.
“After accounting for present-day poverty rate and air pollutants, we still see that previously redlined neighborhoods had higher ED visits related to asthma than those not redlined. This suggests a more widespread, persisting effect of redlining could be responsible for increased asthma burden,” he said. – by Melissa Foster
Disclosures: The authors report no relevant financial disclosures.