Characteristics of self-inflicted injury among suicidal patients: Analysis of nation-wide trauma registry

Purpose Self-inflicted injury is one of the most common causes of suicide. Extremity injury is thought to occur most frequently among penetrating injury; however, epidemiology among patients attempting suicide is unknown. This study aims to find the characteristics of penetrating self-inflicted trauma patients. Methods This is a retrospective cohort study of Japanese nation-wide trauma registry (the Japan National Trauma Data Bank) between January 1, 2004 and December 31, 2017. Patients who attempted suicide with penetrating injury were eligible. We evaluated the occurrence of injury based on injury site (neck/face, chest, abdomen, extremity) as a dependent variable and aging as an independent variable using a generalized linear model and compare those groups with spline models. Results 4576 trauma patients were eligible. Excluding patients with missing age, missing survival data, and missing abbreviate injury score, 4183 patients were enrolled in this study. Common injury site is follows: abdomen 1772 patients (42.4%), extremity 1344 patients (32.0%), neck/face 1253 patients (30.0%), and chest 993 patients (23.7%). The occurrence of neck/face injury, chest injury, and abdominal injury increased with age. On contrary, the rate of extremity injury decreased with age. Conclusions Among self-inflicted trauma patients, abdominal injury was the most common injury, and neck/face injury, chest injury, and abdominal injury were related with aging. On the contrary, the rate of extremity injury decreased as patients' age progressed. Level of evidence Retrospective cohort study, Level III.