Tessler RA, et al. - Researchers sought to analyze national trends in case-fatality percentages at levels I and II trauma centers for injuries due to motor vehicle crashes (MVCs), firearm assault, self-inflicted firearm injury, and unintentional firearm injury by age. In addition, they analyzed trends in injury severity scores (ISSs) and the percentage of out-of-hospital deaths by mechanism. From 2003 to 2013, they observed stagnant case-fatality percentages for firearms alongside declining case-fatality percentages for occupant MVCs. This suggests a worsening of firearm injury severity over time. These findings are not likely explained by changes in the percentage of out-of-hospital deaths

Methods

• From November 15, 2017, to July 4, 2018, researchers performed repeated cross-sectional measures analysis of 1,335,044 patients treated at level I or II trauma centers from January 1, 2003, through December 31, 2013.
• They used 2 data sources: the National Trauma Data Bank National Sample Program, with survey weights to estimate annual median ISS, total injuries and total deaths at levels I and II trauma centers, and the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research for percentages of out-of-hospital deaths.
• Annual case-fatality percentage (total died/total injured), calculated by mechanism across 3 age groups (15-34 years, 35-54 years, and ≥55 years) and 5 categories of ISS (1-15 [mild] 16-24, 25-40, 41-66, and 67-75 [severe]), were the main outcome assessed.
• Annual trends in case-fatality percentage by mechanism, age group, and ISS were estimated using linear regression.
• They estimated annual trends in percentages of out-of-hospital deaths and median ISSs by mechanism.
• The Durbin-Watson statistic for autocorrelation and Prais-Winsten regression models were included in sensitivity analyses.

Results

• Self-inflicted firearm injury had a case-fatality percentage of 42.8%, and assault with a firearm had a case-fatality percentage of 11.1%, the 2 highest of the injuries studied, among 1,335,044 patients treated at level I or II trauma centers.
• Each year, lower injury case-fatality percentage was evident for MVCs but case-fatality percentage did not change for any firearm intent overall or for any age group.
• Overall, they noted an annual increase in median ISS for firearm suicide (0.31; 95% CI, 0.00-0.61).
• Lower annual percentage of out-of-hospital deaths was evident each year for MVCs (−0.24; 95% CI, −0.43 to −0.05) but not for any firearm intents.
• In sensitivity analyses, no longer decline was evident in the annual percentage of out-of-hospital deaths for MVCs.