Suicide-Related Out-of-Hospital Cardiac Arrests in Queensland, Australia: Temporal Trends of Characteristics and Outcomes over 14 Years

Abstract

Background Research into suicide-related out-of-hospital cardiac arrests (OHCA) using OHCA registries is scant. A more complete understanding of methods, patient characteristics, and outcomes is essential to inform prehospital management strategies and public health interventions. Methods Included were all OHCA attended by Queensland Ambulance Service (Australia) paramedics between 1 January 2007 and 31 December 2020, where suicide-related causes could be identified. Age- and sex-standardized incidence rates were calculated. Suicide methods, patient characteristics, and survival outcomes were described. Factors associated with survival outcomes were investigated. Results Seven thousand three hundred and fifty-six suicide-related OHCA cases were included. The incidence rates increased from 9.0 per 100,000 population in 2007 to 12.4 in 2020. The incidence rates for males were four times those for females; however, incidence rates for females have increased faster than for males. Hanging was the most common suicide method (63%). Twenty-three percent of patients received resuscitation attempts by paramedics. Among those, the rates of return of spontaneous circulation (ROSC) sustained to hospital arrival, survival to hospital discharge, and survival to 30 days were 28.6, 8.5, and 8.0%, respectively. Over time, the rates of ROSC upon hospital arrival increased, whereas the rates of survival to discharge and 30-day survival remained stable. Conclusion The incidence of prehospital-identified suicide-related OHCA in Queensland has increased over time. The prognosis of suicide-related OHCA is poor. Prevention measures should focus on early identification and treatment of individuals having a high risk of suicide. Emergency medical services need to have sufficient training for telecommunicators and paramedics in suicide risk assessment and identification.