011 - Longitudinal study on suicide ideation in Canada: exploring associations with suicide attempts, suicide deaths and health service utilization

Suicide is a significant cause of premature death. Suicide is a low base-rate event, 10 suicides per 100,000 per year in Canada, and this makes research challenging. Its predictors exist commonly within people with mental illness, making it difficult to parse out those who will have elevated suicidal risk from those who will not. Many investigations focus on the more readily identifiable stages of the suicidal spectrum: suicidal ideation and suicide attempts rather than suicide deaths. Investigations on help-seeking behaviours of suicidal individuals largely focus on utilization of formal mental health services due to the prevailing conception of suicide as heavily linked to mental illness.
Suicide studies typically use clinical samples, patients with schizophrenia for example, or sample high-risk groups such as adolescents and veterans. In contrast, the studies in this proposal will focus on the general population, and use a large community-representative survey, the Canadian Community Health Survey (CCHS), which has been linked to other health administrative data as well as mortality data. With these large and linked datasets, a unique opportunity exists to study the rare phenomenon of suicidality: sourcing individuals who self-reported suicidal ideation and their rich sociodemographic characteristics from the CCHS, then following these subjects over time to examine their service utilization and suicide attempts patterns using health administration databases, and, if they have died during the follow-up periods, causes of mortality using the Canadian Vital Statistics Database.
Extant literature in this area is also largely cross-sectional in design which, although useful in assessing prevalence and identifying risk factors, do not allow causal inferences to be made. The proposed studies will add value due to their prospective cohort design and multiple follow-up periods (1 year for service utilization, and 1, 3, and 5 years for suicide attempts or suicides) which will provide information of what happens to people with suicidal ideation (PWI) as time passes.
The Poster will present the protocol for three papers: a Scoping Review will be conducted to examine the association between mental health service provision and suicide rates in the general population. The review is near completion and is revealing mixed results (both positive and negative correlations) on this association. Therefore, it is uncertain if mental health service provision makes a difference in improving the suicide rates in the general population.
Second, a prospective cohort study will be conducted on PWI and their use of mental health services by frequency and type over a one-year follow-up period. The study will explore whether PWIs of higher severity use more and specific types of services, compared to those of lesser severity, and compared to persons with no suicidal ideation (PWNI). The impact of mental and substance use disorders will be studied to see if these disorders have a moderating impact on the relationship between suicide ideation and mental health service utilization.
Third, a prospective cohort study will be conducted on PWI and their risk of attempting suicide or dying by suicide. The study will explore if PWIs of greater severity are at higher and earlier risk of suicidal behaviour (attempting suicide or suicide) over 1-, 3- and 5-year follow-up periods. The impact of mental and substance use disorders will be studied to see if these disorders have a moderating impact on the relationship between suicide ideation and suicidal behaviour.
Poisson regression analysis will be used to analyze health service utilization. Cox proportional hazard models will be used to explore suicide attempts and suicide outcomes. Additionally, competing risk analysis will be performed to take into account competing causes of mortality, using the Fine Gray model.

suicide

survival analysis

Poisson regression

competing risk analysis, Fine Gray model 

Beginner

Community

International Conference on Health Policy Statistics 2023