Introduction: Mapping Connections: An understanding of neurological conditions in Canada

Neurological diseases, disorders, and injuries, referred to collectively as neurological conditions, have been estimated to affect 3.6 million Canadians living in the community and a further 170,000 Canadians living in long-term care facilities.^{Footnote 2} The existence of a neurological condition affects not only the individual living with the condition, but also family members and caregivers both within and outside the health care system, thereby increasing the number of Canadians touched by these conditions.

Canadians living with a neurological condition – whether severe or mild, progressive or non-progressive, uncontrolled or controlled – face unique challenges and have specific needs. Symptoms related to these conditions can include paralyzed or weakened muscles, impaired coordination, loss of sensation, seizures, confusion, pain, and altered memory and capacity to think. Neurological conditions can often have an impact on the general physical and mental health of those affected, as well as their relationships with others, capacity to work, and ability to socialize. In the case of children with a neurological condition, their life paths may be altered significantly.

Neurological conditions can occur in individuals of all age groups. Certain conditions that affect the brain, spinal cord, or peripheral nervous system have an onset during infancy or childhood, while others present during adulthood. The prevalence and incidence of some of the most common neurological conditions tend to increase with age.

The aging of the Canadian population

Over a 20-year period from 2011 to 2031, the Canadian population is projected to grow to more than 40 million people. A shift in the population age structure will result in an increase in the number of Canadians age 65 years and older; this proportion will rise from 15% in 2011 to close to one quarter (23%) by 2031 (Figure I-1).^{Footnote 3}  Since the incidence of some of the more common neurological conditions increases with age, as our population ages and grows, both the number of individuals facing the challenges associated with neurological conditions and the cost of caring for these individuals are expected to rise. This burden on health and disability, as well as the need for informal caregiving by families and friends, will result in economic consequences to individuals, caregivers, and the health care system.

Figure I-1: Projected population distribution, by age group, Canada, 2011 and 2031

SOURCE: POHEM-Neurological, cerebral palsy model (Statistics Canada and Public Health Agency of Canada).

Worldwide, there has been an increasing focus on neurological conditions and their relationship to the aging population. In 2006, the World Health Organization (WHO) released a publication entitled 'Neurological disorders: Public health challenges',^{Footnote 4} which brought global awareness to the approaching challenges associated with neurological conditions and an aging population. In Canada, a 2007 report released by the Canadian Institute for Health Information (CIHI), the Canadian Neurological Sciences Federation (CNSF), and the Canadian Brain and Nerve Health Coalition (CBANHC) entitled 'The burden of neurological diseases, disorders and injuries in Canada' echoed the call by the WHO for collective action on neurological conditions.^{Footnote 5} Cognizant of the mounting evidence gathered from Canadian health data, in addition to the ever-increasing health care costs and aging of the population, neurological health charities came together to support these calls for coordinated action in addressing neurological conditions.^{Footnote 6}

The National Population Health Study of Neurological Conditions

The National Population Health Study of Neurological Conditions (the 'Study') was jointly planned and initiated in 2009 through a unique partnership between Neurological Health Charities Canada (NHCC), the Public Health Agency of Canada (the 'Agency'), Health Canada, and the Canadian Institutes of Health Research (CIHR). This Study was designed to: enhance understanding of the scope of targeted neurological conditions in Canada and their impacts on affected individuals, families, and the health care system; support the development of effective programs and services; and reduce the burden of neurological conditions in Canada.

The four focus areas covered by the National Population Health Study of Neurological Conditions

After receiving advice from advisory groups comprised of over 50 experts from the Canadian neurological research community, and with consideration to both the potential population disease burden and key knowledge gaps, the Study was designed to investigate neurological conditions across four focus areas:

1. The impacts on affected individuals, their families, caregivers, and communities;
2. The use of health services, gaps in services, and recommended improvements;
3. The scope in Canada (in terms of prevalence, incidence, and comorbidities); and
4. The risk factors for the development and progression of these conditions.

With a commitment of $15 million over four years (2009 to 2013), thirteen research projects were funded, along with three national surveys (see Appendix 1 for descriptions). In addition, a set of seven microsimulation models was developed by the Agency with Statistics Canada to project the health outcomes and costs of selected neurological conditions. Finally, the Agency's Canadian Chronic Disease Surveillance System (CCDSS) was expanded to use provincial and territorial health administrative data for the surveillance of selected neurological conditions.

Neurological conditions covered by the National Population Health Study of Neurological Conditions

At the onset, 14 diseases, disorders, and injuries of the brain, spinal cord, and peripheral nervous system were selected as part of the Study (Table I-1).Footnote 7 While some research projects and components of the Study focused on subsets or broader groupings of these conditions, others expanded their scope to include additional conditions such as migraine, spinal cord tumour, Rett syndrome, and stroke (Appendix 1; Table A-1). Taking into consideration the varying focus on individual conditions, in addition to certain data limitations (especially for less common conditions), it was not always possible to provide uniform coverage of each neurological condition under study in this report.

A synthesis of the findings from the National Population Health Study of Neurological Conditions

This report describes key findings of the Study, which were identified during a comprehensive synthesis process managed by the Study Implementation Committee that focused on reports prepared by a Scientific Advisory Committee and Synthesis Panel (Appendices 4 to 6). After content review by the Scientific Advisory Committee, the Synthesis Panel reviewed each project and highlighted key findings, knowledge gaps, and main themes in relation to the four focus areas of the Study. In this report, each study component (project or survey) is referred to by its 'short title' or '[reference number]' identified in Appendix 1. Given the vast extent of the issues and topics covered in the Study, this report only attempts to provide a high level overview of the findings from the Study's various components.

The first chapter of this report touches upon the wide spectrum of impacts experienced by Canadians living with a neurological condition – men and women, adults and children, and First Nations and Métis individuals. Impacts on informal caregivers are also presented.

Informed by the diversity and complexity of the impacts of neurological conditions on affected individuals and their families, the second chapter highlights how these impacts translate into unique health service needs across the continuum of care. Although some needs are common across conditions, others are specific to each neurological condition or vary according to the age of the individual affected. The second chapter also presents the health service needs of informal caregivers as well as estimated costs associated with the use of health services for neurological conditions.

To better plan for health service needs and related costs, estimating the number of Canadians living with a neurological condition (as well as the number of new cases that develop each year) is essential. The third chapter presents prevalence and incidence estimates of neurological conditions in Canada, by age and sex for some conditions, and information on their comorbidities. This chapter also explains the necessary requirements for the surveillance of neurological conditions based on valid and accurate estimates.

The human, health service, and economic implications of neurological conditions in Canada constitute strong motivations for an improved understanding of their risk factors. The fourth chapter of this report presents preliminary insights gained by the Study relating to risk factors for neurological conditions, and the remaining challenges associated with the identification of risk factors that are not only supported by statistical evidence but are also relevant from a clinical and public health perspective.

Finally, throughout the report, projections obtained from the microsimulation models are incorporated, to provide insights into the health outcomes and costs of selected neurological conditions in the future. As the understanding of the four focus areas of this Study continues to improve – the impacts (Chapter 1), health service use and needs (Chapter 2), scope (burden) (Chapter 3), and risk factors (Chapter 4) for neurological conditions – governments, health care providers, and stakeholders will have access to a stronger evidence base that can inform policies and the development of strategies that best meet the health and social needs of affected Canadians and their families.