To investigate clinical associations within Canadian psychiatric inpatient suicides.
We conducted a case-control study comparing 98 patients who died by suicide while in hospital and 196 similarly admitted living inpatient controls. All were admitted to an Ontario psychiatric bed between 2008 and 2015 inclusive and had data collected at admission using the Resident Assessment Instrument for Mental Health (RAI-MH). The data were analyzed with bivariate tests and logistic regression modeling.
The strongest associations with inpatient suicide were prior admission to any Ontario psychiatric bed within the previous 30 days (odds ratio [OR] = 6.13), self-harm assessed at prior admission to a psychiatric hospital other than the hospital of suicide (OR = 6.07), and prior admission to a psychiatric hospital other than the hospital of suicide in the previous year (OR = 5.38). A multivariate model using risk factors assessed at admission had an area under the curve (AUC) of 0.77. The model improved to (AUC) 0.81 using a retrospective search of all Ontario admissions to more accurately detect prior admissions. The risk model was optimized to (AUC) 0.83 when the model also included a “discrepancy” variable to denote records in which admission assessment data and retrospective search data did not agree regarding past month admissions.
In addition to the well-known risks of suicide associated with previous suicide attempts and depressive conditions, our data suggest a particular risk of inpatient suicide associated with inpatient care in more than one hospital, particularly when the treating clinicians were unaware of recent previous admissions.