Does Intent Matter? The Medical and Societal Burden of Self-Inflicted Injury

Background: The objective of our study was to assess the impact of injury intentionality on the outcomes and healthcare resource utilization of severely injured patients in the United States. Methods: The National Trauma Data Bank for the years 2001 through 2006 was used for our analysis. Adult patients with an injury severity score 15 were divided into three groups based on injury intentionality: unintentional, assault, and self-inflicted. Demographic and injury characteristics, unadjusted and fisk-adjusted mortality rates, and healthcare resource utilization variables were compared for these three groups using t tests, analysis of variance, and multivariable regression analyses where appropriate. Stata/SE version 9.2 was used for all statistical analyses. p values <0.05 were considered significant. Results: A total of 138,589 patients were included for analysis. After adjustment for potentially confounding variables, self-inflicted injury remained a significant predictor of increased mortality (mortality 42.3%, adjusted odds ratio for death = 2.31, 95% confidence interval 1.97-2.71), and injury by assault a significant predictor of decreased mortality (mortality 18.3%, adjusted odds ratio for death = 0.83, 95% confidence interval 0.74-0.92), when compared with unintentional injury (mortality 15.1%). Patients surviving self-inflicted injury required longer intensive care unit stays and overall hospital stays than survivors of unintentional injury. Conclusions: Patients who are treated for self-inflicted injury have higher risk-adjusted mortality and utilize comparatively higher levels of healthcare resources than victims of assault or patients sustaining unintentional injury. The findings of our study emphasize the need for trauma center participation in the development and maintenance of aggressive primary and secondary suicide prevention programs.