Suicide and self-harm in recent immigrants in Ontario, Canada: a population-based study

Objective — To estimate the rates of suicide and self-harm among recent immigrants and to determine which immigrant-specific risk factors are associated with these outcomes.

Methods — Population-based cohort study using linked health administrative data sets (2003 to 2017) in Ontario, Canada which included adults ≥18 years, living in Ontario (N = 9,055,079). The main exposure was immigrant status (long-term resident vs. recent immigrant). Immigrant-specific exposures included visa class and country of origin. Outcome measures were death by suicide or emergency department visit for self-harm. Cox proportional hazards estimated adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

Results — We included 590,289 recent immigrants and 8,464,790 long-term residents. Suicide rates were lower among immigrants (n = 130 suicides, 3.3/100,000) than long-term residents (n = 6,354 suicides, 11.8/100,000) with aHR 0.3, 95% CI, 0.2 to 0.3. Male–female ratios in suicide rates were attenuated in immigrants. Refugees had 2.1 (95% CI, 1.3 to 3.6; rate 6.1/100,000) and 2.8 (95% CI, 2.5 to 3.2) times the likelihood of suicide and self-harm, respectively, compared with nonrefugee immigrants. Self-harm rate was lower among immigrants (n = 2,256 events, 4.4/10,000) than long-term residents (n = 68,039 events, 9.7/10,000 person-years; aHR 0.3; 95% CI, 0.3 to 0.3). Unlike long-term residents, where low income was associated with high suicide rates, income was not associated with suicide among immigrants and there was an attenuated income gradient for self-harm. Country of origin-specific analyses showed wide ranges in suicide rates (1.4 to 9.9/100,000) and self-harm (1.8 to 14.9/10,000).

Conclusion — Recent immigrants have lower rates of suicide and self-harm and different sociodemographic predictors compared with long-term residents. Analysis of contextual factors including immigrant class, origin, and destination should be considered for all immigrant suicide risk assessment.