A Tale of Two Cities: What's Driving the Firearm Mortality Difference in Two Large Urban Centers?

Abstract

Per police data, the case fatality rate (CFR) of firearm assault in New Orleans (NO) over the last several years ranged between 27% and 35%, compared with 18%-22% in Philadelphia. The reasons for this disparity are unknown, and potentially reflect important system differences with broader implications for the reduction of firearm mortality. A retrospective analysis of police and city-specific trauma databases between 2012 and 2017 was performed. Victims of firearm assaults within city limits were included. Univariate analysis was performed using chi-square for categorical and t-test for continuous variables. Bivariate analysis was conducted using logistic regression. Per police data, the CFR of firearm assault was 31% in NO and 20% in Philadelphia. However, per trauma registry data, the CFR of firearm assault was 14% in NO and 25% in Philadelphia. Patients in Philadelphia were older, had higher injury severity score, and lower blood pressure. Patients in NO had higher rates of head injury. 51% of patients in Philadelphia arrived via police compared to <1% in NO. There was no mortality difference between police and emergency medical service (EMS) transport. Longer EMS prehospital times were associated with increased mortality in NO but not Philadelphia. A much larger percentage of patients died on-scene in NO than Philadelphia. Our findings suggest that the major driver of increased mortality following firearm assault in NO compared with Philadelphia is death prior to the arrival of first responders. Interventions that shorten prehospital time will likely have the greatest impact on mortality in NO. This should include the consideration of police transport.