Self-directed violence and unclear intent presentation within a major trauma system. A multisite analysis

Background: Determining trauma as an act of Self-directed violence (SDV) or from high risk or unclear behaviours is challenging for trauma clinicians and may be affected by patient sex and mechanism of injury. The aim of this study was to examine the differences in characteristics and outcomes between those who have intentionally directed violence towards themselves with those of unclear intent, within a regional trauma system.

Methods: Data was collected between January 2018 and December 2021 in patients who had been identified as a result of either self-directed violence (SDV) defined as any intentional act that can cause injury to one's self, including death or participated in high-risk behaviours, where the intent was unclear (UI). Differences between female and male patients presenting with SDV and unclear intent were explored.

Results: Overall, 2760 patients were identified, with a median age of 39 years (IQR 28-54) and just over a quarter of females (28 %). Falls from height were the most common mechanism of injury in all groups. SDV was recorded in 45 % of patients, and previous mental health diagnoses were almost three times as prevalent in this group compared to those of unclear intent (SDV: 42 % vs UI: 13 %). In the sex-based analysis females were more likely than males to have a history of depression (49 % vs 31 %, p < 0.0001). There were few sex differences in the SDV group but women of unclear intent were older, with a quarter being aged 65 years or over (Females: 26 % vs. Males: 11 %, p < 0.0001). Females of unclear intent were also more likely to have sustained a high level fall (Females: 29 % vs. Males:11 %, p < 0.001).

Conclusion: Previous mental health co-morbidity was associated with self-directed violence in our cohort. Yet the determinants of intent for over half of the patients were unclear. Trauma clinicians should actively enquire regarding intent of injury and escalate to clinical psychology or psychiatry teams as indicated. Those with mental health comorbidities, previous depression and older women may all have an increased risk where intent is unclear and warrants further investigation. Understanding the predictors and characteristics of unclear intent and high-risk behaviours are key to implementation of public health strategies around prevention of self-directed violence and suicide.