Suicide in Canadian veterans living in Ontario: a retrospective cohort study linking routinely collected data

To compare the risk of death by suicide in male veterans with age-matched civilians.

Retrospective cohort study linking provincial administrative databases between 1990 and 2013 with follow-up complete until death or December 31, 2015.

Population-based study in Ontario, Canada.

Ex-serving Canadian Armed Forces and Royal Canadian Mounted Police veterans living in Ontario who registered for provincial health insurance were included. A civilian comparator group was matched 4:1 on age and sex.

Death by suicide was classified using standard cause of death diagnosis codes from a provincial registry of mandatory data collected from death certificates. Fine and Gray sub-distribution hazards regression compared the risk of death by suicide between veterans and civilians. Analyses were adjusted for age, residential region, income, rurality and major physical comorbidities.

20 397 male veterans released to Ontario between 1990 and 2013 and 81 559 age-sex matched civilians were included. 4.2% of veterans died during the study time frame, compared with 6.5% of the civilian cohort. Death by suicide was rare in both cohorts, accounting for 4.6% and 3.6% of veteran and civilian deaths, respectively. After adjustment for confounders, veterans had an 18% lower risk of dying from causes other than suicide (HR 0.82, 95% CI 0.76 to 0.89) and a similar risk of dying by suicide (HR 1.01, 95% CI 0.71 to 1.43), compared with civilians.

Deaths by suicide were rare in male veterans residing in Ontario. Our findings demonstrate that veterans had a similar risk of suicide-related mortality as an age-matched civilian population. A better understanding of effective suicide prevention as well as clarifying pathways to seeking and receiving mental health supports and services are important areas for future consideration.