Suicide mortality among psychiatric patients in Northeast Italy: a 10-year cohort study

Abstract

Aims: The present study investigated the relationship between suicide mortality and contact with a community mental health centre (CMHC) among the adult population in the Veneto Region (northeast Italy, population 4.9 million). Specifically, it estimated the effects of age, gender, time elapsed since the first contact with a CMHC, calendar year of diagnosis and diagnostic category on suicide mortality and modality.

Methods: The regional mortality archive was linked to electronic medical records for all residents aged 18-84 years who had been admitted to a CMHC in the Veneto Region in 2008. In total, 54 350 subjects diagnosed with a mental disorder were included in the cohort and followed up for a period of 10 years, ending in 2018. Years of life lost (YLL) were computed and suicide mortality was estimated as a mortality rate ratio (MRR).

Results: During the follow-up period, 4.4% of all registered deaths were from suicide, but, given the premature age of death (mean 52.2 years), suicide death accounted for 8.7% of YLL; this percentage was particularly high among patients with borderline personality disorder (27.2%), substance use disorder (12.1%) and bipolar disorder (11.5%) who also presented the highest suicide mortality rates. Suicide mortality rates were halved in female patients (MRR 0.45; 95% CI 0.37-0.55), highest in patients aged 45-54 years (MRR 1.56; 95% CI 1.09-2.23), and particularly elevated in the 2 months following first contact with CMHCs (MRR 10.4; 95% CI 5.30-20.3). A sensitivity analysis restricted to patients first diagnosed in 2008 confirmed the results. The most common modalities of suicide were hanging (47%), jumping (18%), poisoning (13%) and drowning (10%), whereas suicide from firearm was rare (4%). Gender, age at death and time since first contact with CMHCs influenced suicide modality.

Conclusions: Suicide prevention strategies must be promptly initiated after patients' first contact with CMHCs. Patients diagnosed with borderline personality disorder, substance use disorder and bipolar disorder may be at particularly high risk for suicide.

Keywords: Cohort study; mental disorder; record linkage study; suicide; suicide mortality.

Fig. 1.

Cumulative mortality risk estimated by Fine and Gray cumulative incidence estimator by diagnostic group for suicide mortality and other causes.

Fig. 2.

Predicted probability of suicidal modality estimated by multinomial regression model for combinations of age of death, gender and time since first contact. HSS, hanging, strangulation and suffocation.