Self-Harm Methods and Repeat Episodes

Recent findings from England suggest that patients who use a combination of self-poisoning and other self-harm methods (e.g., self-poisoning and cutting in the same episode) have three times the risk of future suicide death compared to those who use self-poisoning alone. Additionally, patients who visit the emergency department (ED) multiple times for self-harm during a 7- or 30-day period have nearly four times the risk of future suicide death compared to those who do not. These results indicate that ED patients who use combined self-harm methods or who are seen at the hospital multiple times in a one-month period for self-harm should be flagged to receive additional aftercare support.

Using ED records from two large hospitals in Leeds, researchers sought to identify all episodes of self-harm that occurred between 2004 and 2007. Self-harm was defined as “intentional self-poisoning or self-injury, irrespective of motivation.” Researchers then identified an “index episode” (i.e., the patient’s first hospital visit during the study period). Next, they gathered data on demographic and clinical variables and classified which self-harm method was used in the index episode: self-poisoning only (72.3%), self-cutting (15.5%), self-injury other than cutting (5.3%), and combinations of self-poisoning and self-injury (6.9%). Suicide mortality was determined by linking patient identifiers with mortality data from the Office for National Statistics in England and Wales through August 2011.

Researchers analyzed 10,829 episodes of self-harm among 6,155 people (58% female, 42% male). They found that demographics and presenting characteristics during the index episode could predict future suicide risk. For example, people over age 65 who engaged in self-harm were more than seven times as likely to eventually die by suicide as people ages 10 to 24. Males were more than twice as likely to die by suicide as females. In addition to being at increased risk of future suicide death, patients who engaged in a combination of self-poisoning and another type of self-harm in a single episode were also more likely to return to the hospital for repeat self-harm compared to those who engaged in self-poisoning alone.

Birtwistle, J., Kelley, R., House, A., & Owens, D. (2017). Combination of self-harm methods and fatal and non-fatal repetition: A cohort study. Journal of Affective Disorders, 218, 188–194.