Examining the Influence of Historical Redlining on Firearm Injuries in Current Day Baltimore, Maryland

Firearm injuries are a common and major public health problem in Baltimore, Maryland. The city is also one of the first U.S. cities in which the 1930s discriminatory practice of redlining first emerged. This study examines the association between current day firearm injuries and residence in these historically redlined areas at a neighborhood level using zip codes. Firearm injury outcomes in patients who presented to a hospital in Maryland from 2015 to 2020 were measured from the Health Services Cost Review Commission (HSCRC) in conjunction with both geospatial data from Richmond's Digital Scholarship Lab's Mapping Inequality project and population data from the U.S. Census. A redlining score was calculated to represent the extent of redlining in each zip code. Negative binomial regression models were utilized to measure the association between neighborhood zip codes and rate of firearm injuries. Our adjusted regression model shows that for every one-unit increase of the Home Owners' Loan Corporation (HOLC) redlining score, there is a 2.24-fold increase in the rate of firearm injuries (RR 2.24; 95% CI: 0.31, 1.31, p < 0.001). These findings suggest a strongassociation between historically redlined areas and population risk of firearm injury today. Further research is needed to investigate the underlying mechanisms that may contribute to this relationship, such as access to firearms or social and economic factors. Overall, our study highlights the potential impact of historical redlining policies on contemporary health outcomes in Baltimore.