Prevalence, characteristics, and outcomes of suicide-related out-of-hospital cardiac arrest among patients committing self-harm and suicide-attempts in Japan: A nationwide registry study

Background: Suicide-related out-of-hospital cardiac arrest (OHCA) is characterized by extremely low survival rates and represents a considerable global public health concern. This study aimed to investigate the prevalence, characteristics, and outcomes of suicide-related OHCA.
Methods: This multicenter, retrospective cohort study is an analysis of data collected from the JAPAN Registry of Self-harm and Suicide Attempts. Patients were divided into two groups, the OHCA group and the non-OHCA group. The primary outcome was death at 30 days.
Results: Among 1,960 self-harm and suicide attempts patients, 213 patients (10.9 %) were assigned to the OHCA group and 1,747 (89.1%) were in the non-OHCA group. Patients in the OHCA group were older (44 vs. 33 years old, p < 0.001), and the OHCA group had a higher proportion of males compared to the non-OHCA group (122 [57.3%] vs. 604 [34.6%], p < 0.001). Despite missing and unknown data, lower proportions of psychiatric consultation history (54 [30.8%] vs. 1177 [70.5%], p < 0.001), psychiatric hospitalization history (9 [5.1%] vs. 386 [23.1%], p < 0.001), and previous suicide attempts (16 [9.2%] vs. 807 [48.4%], p < 0.001) were observed in the OHCA group. Risk of death at 30 days was significantly higher in the OHCA group (200 [93.9%] vs. 31 [1.8%], p < 0.001).
Conclusion: Suicide-related OHCA was rare and associated with poorer prognosis compared to patients without OHCA. It was more common in middle-aged men without a history of psychiatric care or prior suicide attempts, although the study was limited by missing data.