Are patients with self-inflicted injuries more likely to die?

Suicide represents one of the leading causes of trauma in industrialized countries. However, when compared with unintentional injury and assault, the outcome of self-inflicted injury has not been well described.

All patients admitted to a French academic trauma center from January 2002 to December 2004 and listed in a trauma data bank were included in a prospective analysis. Variables including mortality, circumstances (unintentional vs. assault vs. self-inflicted), and mechanism of injury were recorded.

About 1,004 continuous trauma patients were analyzed: 151 (15%) with self-inflicted injuries, 761 (76%) with unintentional injuries, and 91 (9%) with injuries from assault. When compared with patients suffering from unintentional injuries and assault, self-inflicted injury patients presented more frequently after a fall from height (94 of 151 vs. 133 of 759 and 0 of 91, p < 0.05) and with a severe head injury (47 of 151 vs. 172 of 752 and 10 of 91, p < 0.05). They also had a more severe injury (Injury Severity Score, 28 +/- 21 vs. 22 +/- 16 and 12 +/- 10; p < 0.05), a lower probability of survival (Trauma Related Injury Severity Score, 0.71 +/- 0.37 vs. 0.83 +/- 0.28 and 0.92 +/- 0.19; p < 0.05), and survival rate (70% vs. 85% and 93%, p < 0.05). In multivariate analysis, Trauma Related Injury Severity Score (odds ratio, 0.54; 95% confidence interval, 0.45-0.59; p < 0.001), age (odds ratio, 1.17; confidence interval, 1.02-1.34; p < 0.05), and mechanism of trauma (p = 0.01) were independently correlated with the final mortality rate.

Self-inflicted injury patients presented with a higher mortality rate that was related to increased injury severity. The circumstances surrounding the trauma were not independently associated with an increased odds ratio of death after major trauma.