Suicide versus homicide firearm injury patterns on trauma systems in a study of the National Trauma Data Bank (NTDB)

Firearm related mortality in the USA surpassed all other developed countries. This study hypothesizes that injury patterns, weapon type, and mortality differ between suicide groups as opposed to homicide. The American College of Surgeons National Trauma Database was queried from January 2017 to December 2019. All firearm related injuries were included, and weapon type was abstracted. Differences between homicide and suicide groups by sex, age, race, and injury severity were compared using a Mann–Whitney test for numerical data and Fisher’s exact test for categorical data. The association between weapon type and mortality relative to suicide as opposed to homicide was assessed in Fisher’s exact tests. Significance was defined as p < 0.05. There were 100,031 homicide and 11,714 suicide subjects that met inclusion criteria. Homicides were mostly assault victims (97.6%), male (88%), African–American (62%), had less severe injury (mean (ISS) 12.07) and a median age of 20 years old (IQR: 14, 30, p < 0.01). Suicides were mostly male (83%), white (79%), had more severe injury (mean ISS 20.73), and a median age of 36 years old (IQR: 19, 54, p < 0.01). Suicide group had higher odds of head/neck (OR = 13.6) or face (OR = 5.7) injuries, with lower odds of injury to chest (OR = 0.55), abdominal or pelvic contents (OR = 0.25), extremities or pelvic girdle (OR = 0.15), or superficial soft tissue (OR = 0.32). Mortality rate was higher for suicide group (44.8%; 95% confidence interval (CI) 43.9%, 45.7%) compared to the homicide group (11.5%; 95% CI 11.3%, 11.7%). Suicide had higher mortality, more severe injuries, and more head/neck/facial injuries than homicide. Majority of suicides were with handguns.