News Release

Historically redlined areas face disparities in emergency medical access and serious consequences for patients, new study finds

Peer-Reviewed Publication

Columbia University's Mailman School of Public Health

August 12, 2025 — A new study published in JAMA Network Open reveals that the legacy of redlining—a discriminatory housing policy from the 1930s—is associated with inequities in rapid access to emergency medical services (EMS) today. These disparities in prehospital care can have serious consequences for patients experiencing life-threatening conditions such as major trauma, stroke, cardiac arrest, or septic shock.

The nationwide study found that communities once labeled as “hazardous” (Grade D) on historical Home Owners’ Loan Corporation (HOLC) maps are significantly less likely to receive timely EMS access compared with neighborhoods deemed “most desirable” (Grade A). The findings highlight the enduring  impact of structural racism on access to critical, life-saving care.

“While disparities in EMS access were known, our study is the first to analyze the association between historical redlining and rapid EMS availability on a national scale,” said Dustin Duncan, ScD, co-author and Professor of Epidemiology at Columbia University Mailman School of Public Health and Associate Dean for Health Equity Research. “Our findings reveal a novel and significant disparity that adds to the growing body of literature on how redlining still impacts health outcomes today.”

Key Findings:

  • The study analyzed EMS station distribution in 236 U.S. cities using 2020 U.S. Census data and HOLC maps.
  • Of the more than 41 million residents in these cities, approximately 2.2 million (5.4%) lacked rapid EMS access.
  • Grade D areas had a significantly higher proportion of residents without rapid EMS access compared with Grade A areas (7% vs. 4.4%).
  • Grade D neighborhoods had fewer non-Hispanic White residents (39.4% vs. 65%) and more non-Hispanic Black residents (28% vs. 10.4%) than Grade A areas.
  • These communities also experienced lower median incomes and greater population density.

Using historical traffic data and ArcGIS StreetMap network analysis, researchers calculated EMS travel times to determine access levels. Grade D residents were more than 1.5 times as likely to lack rapid EMS access compared to residents in Grade A areas.

Delays in EMS response are associated with increased mortality, particularly in cases involving time-sensitive emergencies, according to co-authors at Rutgers Health—Division of Trauma and Surgical Critical Care. The findings highlight a critical gap in prehospital care that disproportionately affects historically marginalized communities.”

The National Fire Protection Association recommends EMS response within 9 minutes for general emergencies and 5 minutes for life-threatening cases. Failure to meet these benchmarks can result in worse outcomes, reinforcing the importance of equitable EMS distribution as a structural determinant of health.

Recommendations to Address Disparities:

The researchers propose a multi-pronged approach to eliminate inequities in EMS access:

  1. Tracking and public reporting of EMS equity metrics to improve transparency and accountability.
  2. Oversight and planning through an equity lens to ensure historically redlined areas are prioritized in EMS infrastructure development.
  3. Redistributing EMS units using GIS and geostatistical models to improve response times in underserved areas.
  4. Redesigning EMS deployment protocols to ensure faster response to high-need neighborhoods.
  5. Mandating transparency in EMS performance through public reporting systems.
  6. Incorporating community input in EMS planning and decision-making.

“Our study supports the urgent need for strategic, data-driven policy interventions at national, regional, and local levels to ensure equitable access to life-saving prehospital care,” Dr. Duncan concluded.

Co-authors include Cherisse Berry, lead author at Rutgers Health; Joseph Obiajulu, Charles DiMaggio, Ashley Pfaff, Spiros Frangos, and Gbenga Ogedegbe (New York University Grossman School of Medicine); N. Clay Mann (University of Utah School of Medicine); Jakka Sairamesh (CapsicoHealth, Inc.); Natalie Escobar (University of California, San Francisco School of Medicine); and Ran Wei (University of California, Riverside).

The research was supported by the National Institute on Minority Health and Health Disparities grant 5R01MD018177.

Columbia University Mailman School of Public Health

Founded in 1922, the Columbia University Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Columbia Mailman School is the third largest recipient of NIH grants among schools of public health. Its nearly 300 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change and health, and public health preparedness. It is a leader in public health education with more than 1,300 graduate students from 55 nations pursuing a variety of master’s and doctoral degree programs. The Columbia Mailman School is also home to numerous world-renowned research centers, including ICAP and the Center for Infection and Immunity. For more information, please visit www.mailman.columbia.edu.


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