Characteristics of patients repeatedly presenting to the emergency department for self-harm injuries: a 6-year retrospective study

Background: Self-harm is a risk factor for suicide completion, and repeated self-harm carries an even greater risk. This study aimed to assess the characteristics of patients who repeatedly presented to the emergency department (ED) for self-harm. Methods: We conducted a retrospective analysis of data from the ED‑Based Injury In‑Depth Surveillance registry in South Korea from January 2017 to December 2022. Patients aged 19–65 years with recorded information on prior self-harm episodes were included. Data regarding their demographic, pre-hospital, and clinical characteristics, as well as in-hospital mortality, were compared based on the number of prior self-harm episodes (0, 1, or ≥ 2). Univariate logistic regression analyses were performed within each self-harm episode group to evaluate the associations between demographic and pre-hospital characteristics and in-hospital mortality. Results: In total, 6,488 patients who self-harmed were included, of whom 3,650 reported one prior episode and 2,838 reported two or more prior episodes. Most patients were female, with the proportion increasing alongside the number of prior self-harm episodes (0: 57.5%, 1: 66.8%, and ≥ 2: 77.2%). Those presenting with repeated attempts were younger, more likely to be Medical-aid insured, and more likely to use cutting or stabbing as methods of self-harm, but fewer arrived by emergency medical services. Injury severity, hospital admission, and in-hospital mortality decreased as the episode frequency increased. Univariate logistic regression analyses showed that demographic and pre-hospital factors consistently influenced in-hospital mortality across the three groups. Conclusions: Patients with repetitive self-harm were more likely to be female, to use cutting or stabbing as methods, and to have psychiatric issues, and they showed a lower in-hospital mortality rate than those without prior episodes.