Dementia In the Population: Investigation Using Population-Level Administrative Health Data In Ontario, Canada

Abstract

As life expectancy increases and populations age, the burden of disease from dementia is becoming an increasingly significant concern worldwide. The goal of this thesis was to support population health decision-making for dementia, including health resource planning and the development of preventative strategies. A population risk tool for predicting dementia risk among community-dwelling older adults was pre-specified, developed and validated using survival methodology and population-based health surveys linked to administrative data in Ontario. The resulting Dementia Population Risk Tool (DemPoRT) is discriminating and predicts dementia risk across a range of health profiles. This algorithm was then applied to a recent national population health survey and used to describe the population risk and future burden of dementia in Canada, and the impact of unhealthy lifestyle behaviours. In five years, there were approximately 450,000 new dementia cases among individuals 55+ years of age in Canada, of which 40% were associated with unhealthy lifestyle behaviours. Lastly, life expectancy and health care utilization of individuals with dementia was investigated. Administrative data was used to identify all individuals with physician-diagnosed dementia in Ontario from 2014 to 2017, and complete period life table methodology was used to estimate life expectancy and the expected health care utilization of individuals from diagnosis to death. Life expectancy at dementia diagnosis was 5.8 years and was longer for women and those diagnosed before the age of 75. Approximately half of this time was spent in long-term care or receiving home care, inpatient care or outpatient care. Development of policy to prepare for and reduce the burden of dementia requires population health planners to have reliable projections of future disease prevalence and resource requirements, and understanding of what subgroups of the population are at the highest risk and have the highest absolute burden. The results of this thesis will support implementation of Canada’s recently-released dementia strategy by providing detailed information about the current and future burden of dementia, and by informing the development of population-based primary prevention strategies.