Adolescent injury, substance use, and mental health, by Mark Asbridge


Lunchtime conference, September 20, 2022, by Mark Asbridge, Ph.D., Professor, Interim department Head, Community Health & Epidemiology | Emergency Medicine, Dalhousie University, Halifax, Canada 


Summary : Injury is an important public health concern as it is the leading cause of death among Canadian adolescents, produces substantial health, social and economic costs, and disparately affects certain population subgroups such as youth and young adults. Much of the previous research in this area relies on hospitalization records, which only capture the most severe injuries and usually do not include detailed information on patient characteristics or broader structural determinants. This report addresses an important gap in the research by providing a more fulsome picture of adolescent injury with a focus on the “hidden figure” of adolescent injury in Canada – injuries not captured by hospitalization records – as well as key social, mental health, and substance use related determinants. This study draws on data from six national or provincial self-reported surveys to assess the injury burden faced by Canadians ages 11 to 19.  We provide estimates of the prevalence of total, intentional, and unintentional injuries among children and youth in Canada and in each   province. Injury rates are also calculated across ten key social, mental health, and substance use categories to examine differences between population groups. There was substantial heterogeneity in prevalence estimates across the six datasets because of the measures employed in each dataset. For this reason, injury rates in different locations were compared using one dataset with national (excluding the territories) and provincial-level data. Total injury rates based on this dataset ranged from 28% in Nova Scotia to 41% in Saskatchewan, with a national average of 31%. A large majority of these injuries were unintentional (such as falls or injuries resulting from sports or inclement weather), ranging from 80% of total injuries in Québec to 89% of in Saskatchewan and a national average of 84%. There are no clear regional differences in injury rates. Other datasets provided essential contextual information, especially where small sample sizes in the principal dataset either caused imprecise estimates or prevented results from being published entirely. This study finds no consistent association between social disadvantage and higher injury rates. Instead, age, sex, socioeconomic status, and employment status exhibit inconsistent and frequently non-significant associations with injury rates. Conversely, mental health and substance use were more consistently associated with increased injury rates. Adolescents with either a mood or anxiety disorder have higher injury rates in most provinces. Using tobacco, alcohol, cannabis, and/or partaking in binge drinking is associated with higher injury rates in most jurisdictions and in each of the six datasets. The cross-sectional data used in study prevents us from identifying mental health and substance use as causes of adolescent injury in Canada. However, a classic lens through which to understand the determinants of injury suggests that these correlates likely have a causal relationship with injury. This study complements previous research which has largely relied on administrative data focusing on more serious injures, and includes less serious, unreported or unrecorded injuries that are absent from administrative data as they are not reported to the health care system. By shedding light on the ‘hidden figure’ of injury, this study offers a fuller picture of the injury burden among Canadian adolescents. Additionally, considering injury rates in the context of broader social determinants allows for the implementation of interventions directed at specific subpopulations or regions with an elevated risk.


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