Suicide following discharge from inpatient psychiatric care: A retrospective case control study

The period following discharge from psychiatric hospitalization is associated with high suicide risk. This study sought to determine the rate and associated risk factors of individuals who die by suicide after discharge in Ontario, Canada.

This retrospective case-control study, spanning from 2006-2018, utilized Ontario data to compare individuals who died by suicide within 7, 30, and 90 days of discharge with controls. Clinical, demographic, and healthcare utilization factors were compared. A Cox proportional hazards model was utilized to determine factors independently associated with suicide.

Across 615,067 psychiatric discharges, there were 320, 771, and 1325 suicide deaths within a 7-, 30-, and 90-day period respectively. These deaths correspond to a suicide rate of 2713, 1525, and 882 deaths per 100,000 person-years and 0.52, 1.25, and 2.15 suicides per 1000 discharged individuals. Cases were more likely to be male, aged 45-54, involve unplanned discharge and a history of suicidal behaviour, and admitted for mood or adjustment disorders. Rural residence, income, medical comorbidity, alcohol, substance use disorder, and psychotic illness were not significantly associated with suicide. Healthcare service utilization did not differ significantly.

The suicide rate is highest immediately following discharge and remains elevated above that of the general Canadian population throughout the 90 days afterward. Risk factors identified include mood disorders, male sex, middle age, shorter length of stay, and unplanned discharge - consistent with previous work. Individuals with unplanned discharges and shorter lengths of stay may be good candidates for closer follow-up to mitigate risk.