A new study shows that being admitted to an intensive care unit (ICU) is linked to a small increased risk of future suicide or self-harm after discharge.
The findings show that survivors of critical illness who later died by suicide or had self-harm events had a tendency to be younger, with a history of psychiatric illness, and had received invasive life support. These results are particularly important in light of the large number of ICU survivors due to the COVID pandemic. The study was published in The BMJ.
The researchers stressed that while the overall risk is still very low, knowledge of these factors “might allow for earlier intervention to potentially reduce this important public health problem.”
Survival after critical illness is associated with important effects, including muscle weakness, reduced exercise capacity, fatigue, cognitive impairment, pain, and financial hardship. Evidence is piling up that shows that ICU survivors have higher rates of psychiatric illness. Some 17–44% of ICU survivors have psychiatric symptoms. However it is yet not known whether that results in an elevated risk of suicide and self-harm.
Researchers in the Canada and the US therefore set out to analyse the association between survival from critical illness and suicide or self-harm after hospital discharge.
For their study, the researchers drew on health records for 423 000 adult ICU survivors in Ontario, Canada from 2009 to 2017.
They matched health records for 423 000 adult ICU survivors (average age 62 years, 39% women) with 3 million non-ICU hospital survivors with similar risk factors for suicide in Ontario, Canada from 2009 to 2017.
The researchers took into account possible confounding factors such as age, sex, mental health history, and previous hospitalisation for self-harm.
Among ICU survivors, it was found that 0.2% of patients died by suicide compared with 0.1% of non-ICU hospital survivors.
Self-harm was seen in 1.3% of ICU survivors compared with 0.8% of non-ICU hospital survivors.
ICU survivors were found to have a 22% higher risk of suicide compared with non-ICU hospital survivors risk of self-harm was 15% higher. The increased risk was greatest after discharge, and persisted in a reduced manner for several years afterward.
Younger ICU survivors (ages 18-34), were most likely to be at risk for suicide, along with those with pre-existing diagnoses of depression, anxiety or PTSD, and those who received invasive procedures such as mechanical ventilation or mechanical blood filtration due to kidney failure in the ICU.
This is a large study involving a cohort of consecutive ICU survivors from an entire population, with minimal missing data. However, given the observational design, the researchers cannot rule out the possibility that other unmeasured factors may have affected their results, and say these associations require further study.
Despite being a large cohort study from an entire population with little missing data, because it is an observational design the researchers cannot rule out the possibility of unknown factors affecting their results. However, the links do warrant further study.
“Survivors of critical illness have increased risk of suicide and self-harm, and these outcomes were associated with pre-existing psychiatric illness and receipt of invasive life support,” they wrote.
“Knowledge of these prognostic factors might allow for earlier intervention to potentially reduce this important public health problem,” the authors concluded.
Source: News-Medical.Net
Journal information: Fernando, S.M., et al. (2021) Suicide and self-harm in adult survivors of critical illness: population based cohort study. BMJ. doi.org/10.1136/bmj.n973.
