Surveillance of Child and Youth Mental Disorders and Associated Service Use in Canada

Introduction

Public health surveillance is defined as the continuous and dynamic process of observing and measuring a target in a specific population over time and space. It includes continuous measurement, data collection, analysis, interpretation, knowledge production, and dissemination to a directed audience including policymakers. ¹ The ultimate goal of public health surveillance is to generate timely evidence to inform public health responses designed to improve population health. ²

Mental disorders, in aggregate, are the leading contributors to disability in children and youth worldwide. ³ Unlike other noncommunicable diseases, which start later in life, approximately half of all mental disorders emerge prior to age 18. ⁴ These disorders are commonly untreated and often persist into adulthood contributing to significant impairment over the life course. ³

In Canada, over the past decade, mental ill-health among youth and young adults aged 12 to 24 has increased, particularly symptoms of depression, anxiety, suicidality, and substance use, disproportionately impacting females. ⁵ In Ontario, perceptions of the need for professional help for mental health concerns among children and youth aged 4 to 16 years tripled from 6.8% to 18.9% between 1983 and 2014. ⁶ Evidence also suggests large and disproportionate mental health treatment gaps, impacting children and youth from immigrant families, and females with mood and/or anxiety disorders. ⁷

Despite these concerning trends, Canada has yet to establish a comprehensive, national approach to the surveillance of mental disorders and associated service use among children and youth.

Current evidence is fragmented and disparate, reflecting heterogeneity in (a) data sources, including both general, population-based surveys and health administrative data; (b) geographical coverage, comprising evidence from local, regional, provincial/territorial, and national levels; and (c) conceptualization and measurement, including measures of perceptions of treatment need, symptoms, functioning, and diagnoses. Furthermore, current surveillance methodology has been largely limited to the use of singular data types (i.e., survey or health administrative data) in isolation (see Supplement 1). We believe there is a need for a national surveillance strategy for children and youth that concerns the unique aspects of this population. Compared to the general population, children and youth require distinct measurement approaches which vary across developmental stages (i.e., preschool-age, children, and youth). Measurement must take into consideration the onset of specific classes of disorders across developmental stages, which require information from multiple informants (youth, parent, and teacher) to be accurate. ⁸ Furthermore, it is required to capture relevant sectors providing mental health care for children and youth, inclusive of school-based services.

Both survey and health administrative data provide distinct coverage of the population and are characterized by a diverse range of strengths and limitations for measuring mental disorders at the population level (see Figure 1). One key distinction between these data sources is that both capture different estimates of prevalence. Specifically, survey data is used to estimate the population prevalence of mental disorders (i.e., an estimate that can be generalized back to the target population). In contrast, health administrative data is most appropriately used to estimate the contact or treated prevalence of mental disorders (i.e., an estimate of who contacts, or who is treated in the health care system (often limited to physicians) with signs or symptoms of a mental disorder). ⁹

OPEN IN VIEWER

Figure 1.

Using population surveys and health administrative data to monitor child and youth mental disorders and associated service use. The three boxes present the strengths and limitations of (a) general population surveys; (b) health administrative data; and (c) the linkage between these two data sources to monitor child and youth mental disorders and associated service use. The Venn diagram in the centre describes a theoretical estimate of different proportions of the population of children and youth (depicted as overlapping circles). The outer circle of the diagram (green) describes the entire population of interest, and the inner circles reflect samples of children and youth ascertained through the various data collection methodologies. The yellow circle represents general population survey samples, and the blue circle represents population health administrative data samples. The red overlapping circle represents the sample of the total population of interest with a mental disorder that is captured to varying degrees by general population survey sampling and population health administrative data.

Rather than relying on either general population-based surveys or health administrative data for surveillance purposes, recent methodological and data analytic advances have highlighted the benefits of linking survey and health administrative data to generate prevalence estimates of mental disorders and service utilization. ¹⁰ Linked data can be used to overcome certain limitations present in each data type, including adding longitudinal follow-up of administrative data for survey participants and adding more comprehensive coverage, such as standardized measures of mental disorders, service use by other providers, and sociodemographic data for health administrative data. Data linkages offer the ability to improve both the temporal coverage and the accuracy of various indicators that have been proposed to be essential components for informing mental health care systems.^10,11 For example, the accuracy of mental health-related service use among children and youth, commonly measured using health administrative data alone, would be improved if estimates of nonphysician and private practitioner service use, obtained through survey data, or from institutions themselves, were integrated using data linkages. Furthermore, administrative-survey data linkage is currently our best means of measuring the alignment of population mental disorders and service use/nonuse over time, which is an important indicator measuring potential gaps between need and use that could be used to inform policymakers.^7,11,12 It is important to note that the introduction of data linkage brings with it unique challenges and potential sources of bias arising both from the survey and administrative data. Specifically, recall bias can affect the validity of survey-based measures and probabilistic classification of administrative data (e.g., using probabilistic case definitions) can result in error. ¹³ Moreover, misclassification of mental health-related service contacts for children and youth can arise when parents or caregivers seek care for a child with mental health concerns on their own. In addition, bias can arise from the linkage process itself, which is determined by a combination of participant consent and patterns of missing data, both of which can potentially impact the representativeness of linked cohorts (see Figure 1). ¹⁴ Here, we outline current surveillance efforts, highlight content and methodological gaps, and propose a vision for the future of surveillance of child and youth mental disorders and associated service use in Canada.

Current Surveillance Methodology

Evidence Gaps

There is currently a lack of consensus on how to measure and quantify mental disorders at the population level. As a result, we lack robust empirical evidence to answer fundamental questions related to the number of children and youth in Canada with a mental disorder. Furthermore, we have no centralized way of tracking the numbers seen by service providers for mental health-related concerns, inclusive of all sectors that serve this population, that is, health, education, community mental health and social services, and justice services. ⁷ Another important gap is our capacity to conceptualize and measure the reach and targeting of mental health services, including the alignment of “need” for mental health services and service receipt—defined as the proportion of children with and without a mental disorder who have and have not received mental healthcare.^11,12 These 3 core concepts—prevalence of mental disorders, service use, and reach and alignment of mental health services—represent critical information gaps that are central for informing policymaking. ¹¹ These gaps exist for both national and provincial/territorial approaches to surveillance.

Vision for the Future of Surveillance

Current surveillance in Canada lacks the specificity required to meaningfully inform child and youth mental health policy. We must both create high-quality population-level data and make better use of the data we currently have, to support policymakers as they plan to address the population-based needs for mental health services for children and youth in Canada. The development of analytic methods that combine multiple sources of data, including individually linked high-quality survey and health administrative data, is also needed to arrive at valid and generalizable estimates.

Future surveillance initiatives for child and youth mental disorders should be supported by federal leadership and facilitated by collaborative cross-sectoral and interprovincial/territorial partnerships. We need to include a diverse range of young people and caregivers with lived experiences, clinicians, senior administrators, researchers, and policymakers to help ensure the data are appropriate and useful for all stakeholders. The national leadership of surveillance efforts has numerous strategic advantages including collaborative partnerships across the country and the establishment of national standards for conceptualizing, measuring, collecting, appraising, integrating, and interpreting child and youth mental health data. Examples of successful national surveillance efforts include major disease surveillance systems for cancer and diabetes (see Supplement 1).

Conclusion

Given increases in mental ill-health, ⁵ associated impairments, ³ and service shortages ²⁹ affecting Canadian children and youth—and when considering current and future economic costs ³⁰ of mental disorders—it is imperative that we invest now in evidence-informed mental health policy by building capacity for the collection, use, and integration of mental health data for children and youth in Canada. Surveillance is at the heart of understanding health conditions and is key to informing policymakers as they address population-based needs. It is time to prioritize child and youth mental health in Canada by investing in developing, sustaining, and continuously enhancing a robust mental disorder surveillance system developed explicitly for children and youth.

Supplemental Material