Aims of the study: In Switzerland, suicide is a major cause of years of potential life lost. Among people who died by suicide, a significant number suffered from mental illness and were treated by psychiatric care institutions. Psychiatric patients are thus a specific target for suicide prevention. Based on data from a clinical committee reviewing every death by suicide of psychiatric patients in the Canton of Vaud (Switzerland), this observational study aimed to gain knowledge on sociodemographic and clinical characteristics of psychiatric patients who died by suicide by comparing in- and outpatients.

Methods: Sociodemographic and clinical characteristics of patients who died by suicide in our department from January 2007 to December 2019 were analysed. In- and outpatients were compared.

Results: The sample included 153 patients (64.7% males, n = 99). Three quarters (76.4%, n = 81) of the patients had at least one previous suicide attempt. In- and outpatients did not differ significantly in terms of sociodemographics data, psychiatric diagnosis or method of suicide. Almost all (97.2%) of the outpatients had at least one past psychiatric hospitalisation. We found gender disparities for several variables and a lower male/female suicide ratio than in the general Swiss population. Seventy-two percent of the outpatients (n = 49) had a last personal contact with clinicians less than a week before their suicide and 38.8 % of those less than 24 hours (28% of outpatients, n = 19).

Conclusions: Patients dying by suicide present most of the time a serious psychiatric history. In- and outpatients seem to have a similar clinical and sociodemographic profile and suicide prevention should thus not be addressed differently in these two groups. The time between death of outpatients and last contact with a therapist was shorter than expected.