Comparison of Clinical Indicators for Non-Suicidal Self-Injury and Suicide Attempts in the Emergency Department

While differentiating non-suicidal self-injury (NSSI) from minor intent suicide attempts (MSAs) and serious intent suicide attempts (SSAs) is crucial for providing effective crisis interventions in emergency departments (EDs), existing research on this distinction remains limited. Therefore, this study aims to identify clinical indicators differentiating NSSI, MSA, and SSA among ED patients.

Data were collected from 587 patients who presented with self-injurious behaviors at Chung-Ang University Hospital ED in Seoul from June 2018 to December 2023. The study assessed patients' suicide attempt intentionality, demographic and historical factors, characteristics of self-injury, status at self-injury, as well as suicidal ideation and suicide planning upon presentation to the ED. Patients were classified into NSSI, MSA, or SSA groups based on the intentionality of their self-injury. Hierarchical logistic regression analyses were performed to identify clinical indicators distinguishing these groups.

Among all self-injury patients, sex (odds ratio [OR], 0.45; P = 0.029), higher lethality of injury (OR, 5.34; P < 0.001), and sustained suicidal ideation (OR, 2.83; P = 0.002) were clinical indicators that distinguished intentional suicide attempts (MSA and SSA) from NSSI. Among patients with NSSI and MSA, those with a higher lethality of injury (OR, 2.88; P = 0.002) and sustained suicidal ideation (OR, 2.87; P = 0.005) were more likely to have MSA. By contrast, for patients with intentional suicide attempts (MSA and SSA), the following factors were significant predictors of SSA: method of cutting (OR, 0.17; P < 0.001), higher lethality of injury (OR, 6.01; P < 0.001), self-injury under the influence of alcohol (OR, 1.76; P = 0.041), and help-seeking at the time of self-injury (OR, 0.48; P = 0.004).

Being male, higher injury lethality, and sustained suicidal ideation are significant clinical indicators predicting suicidal attempt rather than NSSI. Among patients attempting suicide, methods other than cutting, high-lethality attempts, self-injury under the influence of alcohol, or not seeking help may indicate serious suicidal intentions, necessitating thorough evaluation and possible emergency hospitalization.