Risk of suicide in patients who present to hospital after self-cutting according to site of injury: findings from the Multicentre Study of Self-harm in England

Background: We compared the risk of death by suicide following hospital presentation for self-harm according to site of self-cut/stab.
Method: We included 54,999 self-harm presentations (involving 31,419 individuals) to hospitals in the Multicentre Study of Self-harm in England (1/1/2004-31/12/2014), with mortality follow-up to 31/12/2019. Information on method of self-harm was obtained through monitoring in hospitals. Information about mortality was obtained through linkage with NHS Digital. We assessed the association of site of self-cut with death by suicide using mixed effect models.
Results: 10,790 (19.6%) hospital presentations involved self-cutting/stabbing, 7,489 of which (69.4%) were due to laceration to the arm/wrist alone, 1,846 episodes (17.1%) involved cutting elsewhere on the body, and 1,455 (13.5%) were due to laceration to unknown site. Controlling for confounders, presentation to hospital following self-cut/stab to bodily parts other than wrist/arm was associated with greater chance of subsequent suicide relative to presentation after self-poisoning alone [adjusted odds ratio (aOR) 1.75, 95% confidence interval (CI) 1.03-2.96, P=0.038]. The likelihood of suicide after presentation for cutting/stabbing the wrist/arm alone was comparable to that of patients who had self-poisoned alone. Presentations after laceration involving the neck were associated with a 4-fold greater chance of subsequent suicide relative to self-poisoning (aOR 4.09, 95% CI 1.80-9.30, p=0.001).
Conclusions: Patients who attend hospital after self-cutting/stabbing are a heterogeneous group in terms of characteristics, methods of cutting/stabbing and risk of subsequent suicide. Risk of suicide is greater in individuals who self-cut/stab to parts of the body other than the wrist or arm, especially the neck.