Long-term outcomes of patients admitted to an intensive care unit with intentional self-harm

Self-harm is one of the most common reasons for admission to an intensive care unit (ICU). While most patients with self-harm survive the ICU admission, little is known about their outcomes after hospital discharge. We conducted a retrospective cohort study of patients in the Barwon region in Victoria admitted to the ICU with self-harm (between 1998 and 2018) who survived to hospital discharge. The primary objective was to determine mortality after hospital discharge, and secondarily estimate relative survival, years of potential life lost, cause of death and factors associated with death. Over the 20-year study period, there were 710 patients in the cohort. The median patient age was 37 years (interquartile range (IQR) 26-48 years). A total of 406 (57%) were female, and 527 (74%) had a prior psychiatric diagnosis. The incidence of ICU admission increased over time (incidence rate ratio 1.05; 95% confidence interval (CI) 1.03-1.06 per annum). There were 105 (15%) patients who died after hospital discharge. Relative survival decreased each year after discharge, with the greatest decrement during the first 12 months. At ten years, relative survival was 0.85 (95% CI 0.81-0.88). The median years of potential life lost was 35 (IQR 22-45). Cause of death was self-harm in 27%, possible self-harm in 32% and medical disease in 41%. The only factors associated with mortality were male sex, older age and re-admission to ICU with self-harm. Further population studies are required to confirm these findings, and to understand what interventions may improve long-term survival in this relatively young group of critically ill patients.