A population-based study on the epidemiology of firearm-related injury in Nova Scotia

Objective: Firearm-related trauma is a significant cause of preventable mortality. In 2020, Nova Scotia experienced the largest mass shooting in Canadian history. The objective of this study was to describe the epidemiology of firearm-related injury and death in Nova Scotia and to assess for factors associated with mortality. Methods: A retrospective observational study of all major trauma patients in Nova Scotia who sustained firearm-related injuries between 2001 and 2020 was conducted. Data was collected from the Nova Scotia Trauma Registry and the Nova Scotia Medical Examiner Service. Injury rates were evaluated over time, by age/sex, and by intent (assault/homicide, self-harm, other), and were mapped by municipality. Characteristics of survivors and non-survivors were compared using t-tests and chi-square analysis. A multivariate logistic regression model was created to assess for predictors of mortality. Results: A total of 776 firearm-related injuries occurred over the 19-year study period, for an overall age- and sex-adjusted firearm injury rate of 4.44 per 100,000 population. Patients ranged in age from 6 to 92 years (mean 45.0±19.2 years) and most were male (95.6%; 742/776). Injuries were predominantly self-inflicted (65%; 504/776). The majority of patients died from their injuries (72%; 558/776); 64% (497/776) died at the scene. The overall age- and sex-adjusted firearm mortality rate was 3.18 per 100,000. Most non-survivors had injuries that were self-inflicted (83.2%; 464/558). Increasing age (OR 1.02, 95% CI 1.00-1.04) and increasing Injury Severity Score (OR 1.11, 95% CI 1.07-1.15) were associated with greater likelihood of mortality. Activation of the trauma team was associated with survival (OR 0.04, 95% CI 0.02-0.10). Conclusion: Trauma patients with firearm-related injuries were predominantly male and most injuries were self-inflicted among middle-aged to older patients. Younger patients tended to be victims of homicide/assault and were more likely to survive their injuries.