Comparative analysis of injuries related to self-harm, assault, and intimate partner violence: insights from U.S. Emergency Departments (2005-2021).

Background: Emergency departments are on the front lines of non-fatal self-harm injury (SHI). This study identifies patterns in patients presenting to emergency departments with SHI compared with patients presenting with assault and intimate partner violence.

Methods: Using the National Electronic Injury Surveillance System All Injury Program database, we analyzed SHI cases in the emergency department from 2005 to 2021 and examined demographic characteristics, injury mechanism and anatomic location, emergency department disposition and temporal patterns relative to cases involving assault and intimate partner violence.

Results: Of all injury-related emergency department visits, 1.5% (7 774 900) were due to SHI, 4.8% (24 165 696) due to assault and 0.6% (3 188 790) due to intimate partner violence. SHI peaked in ages 15-19 (18.3%), assault in ages 20-24 (17.3%) and intimate partner violence in ages 25-29 (19.2%). Patients with SHI were 41.0% males, compared with assault (66.3%) and intimate partner violence (19.3%) groups (p<0.0001). Most SHIs involved white patients (75.2%), compared with assaults (46.2%) and intimate partner violence (40.4%) (p<0.0001). Lacerations (20.6%) were the most common injury for SHI, while contusions/abrasions were the most common injuries for both assaults (27.8%) and intimate partner violence (39.1%) (p<0.0001). The upper extremity was the most common injury location in SHI (71.11%), while the head/neck was the most injured area in assaults (58.4%) and intimate partner violence (59.7%). Of adolescents sustaining SHI, 76.7% were women, compared with 59.0% of emerging adults and 53.2% of adults (p<0.0001). Among adolescents, the prevalence of SHI was lowest on weekends and during the summer.

Conclusions: Our findings highlight distinct demographic, injury and temporal patterns observed in patients with SHI.